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  Subjects -> AGRICULTURE (Total: 781 journals)
    - AGRICULTURAL ECONOMICS (78 journals)
    - AGRICULTURE (528 journals)
    - CROP PRODUCTION AND SOIL (92 journals)
    - DAIRYING AND DAIRY PRODUCTS (31 journals)
    - POULTRY AND LIVESTOCK (52 journals)

AGRICULTURE (528 journals)                  1 2 3 | Last

Showing 1 - 200 of 263 Journals sorted alphabetically
Aceh International Journal of Science and Technology     Open Access   (Followers: 1)
Acta agriculturae Slovenica     Open Access   (Followers: 3)
Acta Agronomica Hungarica     Full-text available via subscription   (Followers: 1)
Acta Agronomica Sinica     Full-text available via subscription   (Followers: 5)
Acta Scientiarum. Animal Sciences     Open Access   (Followers: 1)
Acta Scientiarum. Technology     Open Access  
Acta Technologica Agriculturae     Open Access   (Followers: 1)
Acta Universitatis Sapientiae, Alimentaria     Open Access  
Advances in Agriculture     Open Access   (Followers: 3)
Advances in Agriculture & Botanics     Open Access   (Followers: 9)
Advances in Agronomy     Full-text available via subscription   (Followers: 13)
Advances in Life Science and Technology     Open Access   (Followers: 9)
AFBM Journal     Open Access  
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 9)
African Journal of Agricultural Research     Open Access   (Followers: 3)
African Journal of Food Science     Open Access   (Followers: 3)
African Journal of Food, Agriculture, Nutrition and Development     Open Access   (Followers: 12)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 5)
Agra Europe     Full-text available via subscription   (Followers: 3)
Agribusiness : an International Journal     Hybrid Journal   (Followers: 7)
Agricultura Tecnica     Open Access   (Followers: 6)
Agricultura Tropica et Subtropica     Open Access   (Followers: 1)
Agricultura, Sociedad y Desarrollo     Open Access   (Followers: 1)
Agricultural Advances     Open Access   (Followers: 3)
Agricultural and Food Science     Open Access   (Followers: 14)
Agricultural Commodities     Full-text available via subscription  
Agricultural Economics     Hybrid Journal   (Followers: 43)
Agricultural History Review     Full-text available via subscription   (Followers: 5)
Agricultural Research     Hybrid Journal   (Followers: 3)
Agricultural Science     Full-text available via subscription   (Followers: 4)
Agricultural Science     Open Access   (Followers: 1)
Agricultural Sciences     Open Access   (Followers: 7)
Agricultural Sciences in China     Full-text available via subscription   (Followers: 3)
Agricultural Systems     Hybrid Journal   (Followers: 25)
Agricultural Water Management     Hybrid Journal   (Followers: 22)
Agriculture     Open Access   (Followers: 4)
Agriculture & Food Security     Open Access   (Followers: 8)
Agriculture (Poľnohospodárstvo)     Open Access   (Followers: 1)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Food Sciences Research     Open Access  
Agriculture and Human Values     Hybrid Journal   (Followers: 12)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 45)
Agriprobe     Open Access  
Agrivita : Journal of Agricultural Science     Open Access   (Followers: 2)
Agro-Science     Full-text available via subscription  
Agroalimentaria     Open Access  
Agrociencia     Open Access   (Followers: 1)
Agrociencia Uruguay     Open Access  
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
Agronomía Colombiana     Open Access  
Agronomía Costarricense     Open Access   (Followers: 1)
Agronomía Mesoamericana     Open Access  
Agronomie Africaine     Full-text available via subscription  
Agronomy     Open Access   (Followers: 8)
Agrosearch     Open Access   (Followers: 1)
Akademik Ziraat Dergisi     Open Access  
Alinteri Zirai Bilimler Dergisi : Alinteri Journal of Agricultural Sciences     Open Access  
Ambiente & Agua : An Interdisciplinary Journal of Applied Science     Open Access   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 10)
American Journal of Botany     Full-text available via subscription   (Followers: 15)
American Journal of Economics and Sociology     Hybrid Journal   (Followers: 26)
American Journal of Potato Research     Hybrid Journal   (Followers: 2)
American Journal of Rural Development     Open Access   (Followers: 3)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Annales des Sciences Agronomiques     Full-text available via subscription  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annals of Agricultural Sciences     Open Access   (Followers: 2)
Annals of Silvicultural Research     Open Access   (Followers: 1)
Annual Review of Resource Economics     Full-text available via subscription   (Followers: 10)
APCBEE Procedia     Partially Free   (Followers: 1)
Applied Economics Letters     Hybrid Journal   (Followers: 24)
Applied Financial Economics Letters     Hybrid Journal   (Followers: 7)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
Archivos de Zootecnia     Open Access   (Followers: 1)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arthropod-Plant Interactions     Hybrid Journal   (Followers: 2)
Asian Economic Papers     Hybrid Journal   (Followers: 4)
Asian Journal of Agricultural Research     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 1)
Asian Journal of Plant Sciences     Open Access   (Followers: 1)
Australian Cottongrower, The     Full-text available via subscription   (Followers: 1)
Australian Economic Papers     Hybrid Journal   (Followers: 8)
Australian Economic Review     Hybrid Journal   (Followers: 7)
Australian Forest Grower     Full-text available via subscription   (Followers: 2)
Australian Forestry     Full-text available via subscription   (Followers: 2)
Australian Grain     Full-text available via subscription   (Followers: 3)
Australian Holstein Journal     Full-text available via subscription  
Australian Journal of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3)
Australian Journal of Agricultural Engineering     Open Access   (Followers: 1)
Australian Sugarcane     Full-text available via subscription  
Avances en Investigacion Agropecuaria     Open Access   (Followers: 1)
B.E. Journal of Theoretical Economics     Full-text available via subscription  
Bangladesh Agronomy Journal     Open Access  
Bangladesh Journal of Agricultural Research     Open Access   (Followers: 2)
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Bioagro     Open Access  
Biocatalysis and Agricultural Biotechnology     Hybrid Journal   (Followers: 4)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 6)
Biodiversity     Hybrid Journal   (Followers: 22)
Biodiversity : Research and Conservation     Open Access   (Followers: 23)
Biological Agriculture & Horticulture : An International Journal for Sustainable Production Systems     Partially Free   (Followers: 11)
Biosystems Engineering     Hybrid Journal   (Followers: 4)
Biotemas     Open Access  
Boletín Semillas Ambientales     Open Access  
Bragantia     Open Access   (Followers: 2)
Brazilian Archives of Biology and Technology     Open Access   (Followers: 1)
British Poultry Science     Hybrid Journal   (Followers: 5)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Buletin Veteriner Udayana     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
California Agriculture     Open Access   (Followers: 1)
Cambridge Journal of Economics     Hybrid Journal   (Followers: 40)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 17)
Capitalism Nature Socialism     Hybrid Journal   (Followers: 11)
Ceiba     Open Access  
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
CERNE     Open Access  
CESifo Economic Studies     Hybrid Journal   (Followers: 7)
Change and Adaptation in Socio-Ecological Systems     Open Access   (Followers: 1)
Chemical and Biological Technologies for Agriculture     Open Access  
Chilean Journal of Agricultural Research     Open Access   (Followers: 1)
Ciencia & Natura     Open Access  
Ciência e Agrotecnologia     Open Access  
Ciencia e investigación agraria     Open Access  
Ciência e Técnica Vitivinícola     Open Access  
Ciencia forestal en México     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Ciencia y Agricultura     Open Access  
COCOS : The Journal of the Coconut Research Institute of Sri Lanka     Open Access   (Followers: 1)
Coffee Science     Open Access  
Cogent Food & Agriculture     Open Access  
Competition & Change     Hybrid Journal   (Followers: 9)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 2)
Contributions to Tobacco Research     Open Access   (Followers: 1)
Corps et culture     Open Access   (Followers: 5)
Cuadernos de Desarrollo Rural     Open Access   (Followers: 1)
Cultivos Tropicales     Open Access  
Cultural Geographies     Hybrid Journal   (Followers: 16)
Cultural Sociology     Hybrid Journal   (Followers: 27)
Cultural Studies - Critical Methodologies     Hybrid Journal   (Followers: 15)
Cultural Studies of Science Education     Hybrid Journal   (Followers: 5)
Cultural Trends     Hybrid Journal   (Followers: 13)
Culture & Agriculture     Hybrid Journal   (Followers: 10)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 5)
Current Life Sciences     Open Access   (Followers: 2)
Current Research in Dairy Sciences     Open Access   (Followers: 5)
Dairy Mail Africa : Publication for the Dairy Industry in Africa     Full-text available via subscription   (Followers: 2)
Derim     Open Access  
Developments in Agricultural Economics     Full-text available via subscription   (Followers: 4)
Developments in Agricultural Engineering     Full-text available via subscription  
Diatom Research     Hybrid Journal  
Die Bodenkultur : Journal of Land Management, Food and Environment     Open Access  
Dossiers Agraris     Open Access  
Ecological Applications     Full-text available via subscription   (Followers: 117)
Economic Affairs     Hybrid Journal   (Followers: 6)
Economic and Industrial Democracy     Hybrid Journal   (Followers: 6)
Economic Bulletin     Hybrid Journal   (Followers: 4)
Economic Policy     Hybrid Journal   (Followers: 25)
Economic Record     Hybrid Journal   (Followers: 4)
Empirical Economics     Hybrid Journal   (Followers: 8)
Encuentro     Open Access  
Engineering in Agriculture, Environment and Food     Hybrid Journal  
Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde     Open Access  
Environment and Development Economics     Hybrid Journal   (Followers: 26)
Eppo Bulletin     Hybrid Journal   (Followers: 2)
Ethology     Hybrid Journal   (Followers: 7)
EU agrarian Law     Open Access   (Followers: 3)
Euphytica     Hybrid Journal   (Followers: 7)
Eurochoices     Hybrid Journal   (Followers: 1)
European Agrophysical Journal     Open Access  
European Journal of Agronomy     Hybrid Journal   (Followers: 9)
European Journal of American Culture     Hybrid Journal   (Followers: 2)
European Journal of Health Economics     Hybrid Journal   (Followers: 17)
European Journal of Law and Economics     Hybrid Journal   (Followers: 58)
European Review of Agricultural Economics     Hybrid Journal   (Followers: 10)
EvoDevo     Open Access   (Followers: 2)
Extensão Rural     Open Access   (Followers: 1)
Farmer’s Weekly     Full-text available via subscription  
Farmlink Africa     Full-text available via subscription  
Fitosanidad     Open Access  
Folia Horticulturae     Open Access   (Followers: 1)
Food and Agricultural Immunology     Hybrid Journal   (Followers: 2)
Food and Energy Security     Open Access   (Followers: 4)
Food Biotechnology     Hybrid Journal   (Followers: 11)
Food Economics - Acta Agriculturae Scandinavica, Section C     Hybrid Journal   (Followers: 2)
Food New Zealand     Full-text available via subscription   (Followers: 3)
Food Policy     Hybrid Journal   (Followers: 28)
Forestry Chronicle     Full-text available via subscription   (Followers: 10)
Forum for Health Economics & Policy     Hybrid Journal   (Followers: 7)
Frontiers in Science     Open Access   (Followers: 1)
Frontiers of Agriculture in China     Hybrid Journal   (Followers: 2)
Future of Food : Journal on Food, Agriculture and Society     Open Access   (Followers: 1)
Geoderma     Hybrid Journal   (Followers: 8)
Ghana Journal of Agricultural Science     Full-text available via subscription   (Followers: 2)
Global Approaches to Extension Practice : A Journal of Agricultural Extension     Full-text available via subscription   (Followers: 1)
Global Economic Review     Hybrid Journal   (Followers: 6)
Global Journal of Agricultural Sciences     Full-text available via subscription  
Hacquetia     Open Access  
Handbook of Agricultural Economics     Full-text available via subscription   (Followers: 4)

        1 2 3 | Last

Journal Cover Biosystems Engineering
  [SJR: 0.773]   [H-I: 66]   [4 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1537-5110 - ISSN (Online) 1537-5129
   Published by Elsevier Homepage  [2969 journals]
  • Use of geophysical data for assessing 3D soil variation in a durum wheat
           field and their association with crop yield
    • Abstract: Publication date: Available online 25 July 2016
      Source:Biosystems Engineering
      Author(s): Giovanni Cavallo, Daniela De Benedetto, Annamaria Castrignanò, Ruggiero Quarto, Alessandro Vittorio Vonella, Gabriele Buttafuoco
      From the perspective of Precision Agriculture, the delineation of management zones in agricultural fields to optimise the use of soil and water resources and increase farmer's profitability requires knowledge of fine-scale variability. The objective of this paper is to delineate management zones in terms of yield performance verifying the suitability of Ground Penetrating Radar (GPR) to assess spatial variation of soil properties. In a durum wheat field in southern Italy, yield data were recorded and a GPR survey carried out after harvesting. On the basis of spatial distribution of the yield, the field was split into four management zones (MZs) and the expected values and standard deviations of GPR signal amplitude data were estimated using polygon kriging for each MZ. In order to interpret the results and assess the resistivity of the soil, the total sand content and bulk electrical conductivity from an electromagnetic induction (EMI) sensor were estimated by polygon kriging. The acquisition of very fine-scale soil information with GPR allowed 3D variability in the field to be imaged. Further, the study has shown the existence of a physically-based relationship between the yield of the wheat and the structural properties of the soil detected by GPR.


      PubDate: 2016-07-28T21:23:21Z
       
  • Assessment of laboratory VIS-NIR-SWIR setups with different spectroscopy
           accessories for characterisation of soils from wildfire burns
    • Abstract: Publication date: Available online 18 July 2016
      Source:Biosystems Engineering
      Author(s): Olga A. Rosero-Vlasova ​, Fernando Pérez-Cabello, Raquel Montorio Llovería, Lidia Vlassova
      Thousands of hectares of Mediterranean forests are burned every year. Fires affect all the landscape components. They trigger erosion processes, which can have catastrophic consequences. Thus, detection and post-fire monitoring of soil properties is of great importance. Changes in soil caused by the fire can be detected by proximal soil sensing. In this context, the study evaluates the applicability of laboratory experimental setups for spectral analysis of burnt soils. Three setups of Analytical Spectral Device (ASD) FieldSpec®4 spectroradiometer with different spectroscopy accessories (external integrating sphere, illuminator lamp and contact probe) were used for measurement of reflectance spectra and evaluation of soil organic matter (SOM) in 82 soil samples from wildfire burns in Aragon, Northern Spain. No statistically significant differences were detected between values obtained by different setups. Lower reflectances registered with integrating sphere are probably due to the fact that the internal cavity of the device is not perfectly spherical because of the existence of multiple port windows. Measurements with Illuminator lamp and contact probe were more stable and corresponding calibration models for SOM built using partial least square regression combined with step-down variable selection algorithm (SA-PLSR) demonstrated acceptable predictive ability (0.75 ≤ R2 V ≤ 0.81; 2.00 ≤ RPD ≤ 2.55). The coefficients are ∼10% higher than those obtained with the integrating sphere. The study demonstrated feasibility of using Visible – Near InfraRed – Short Wave InfraRed (VIS-NIR-SWIR) spectroscopy for monitoring post-fire evolution of burnt soils and showed that the choice of the appropriate accessory (e.g., Illuminator lamp) improves the reliability of SOM estimations.


      PubDate: 2016-07-23T21:03:59Z
       
  • Stomatal resistance of New Guinea Impatiens pot plants. Part 2: Model
           extension for water restriction and application to irrigation scheduling
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Patrice Cannavo, Hacène Bouhoun Ali, Etienne Chantoiseau, Christophe Migeon, Sylvain Charpentier, Pierre-Emmanuel Bournet
      In greenhouses, reducing water consumption by increasing water efficiency is of high interest. To reach this goal, predictive models of soil-plant-atmosphere water transfer could be helpful. However, such models have been mainly developed for open field conditions, and very few models exist for greenhouse plants grown in pots. Moreover, most of these models were implemented under well-watered conditions, but very few are available under water restriction. The aim of this study is to develop an integrated soil-plant-atmosphere water balance model applied to potted plants grown in greenhouses, to predict plant transpiration under different restrictive irrigation regimes. Implementing such a model requires an accurate estimation of stomatal resistance R s under water restriction conditions. R s is then used in the Penman-Monteith model to evaluate transpiration. To establish the model parameters, an experiment was conducted for sixteen weeks inside a greenhouse with ornamental plants (New Guinea Impatiens) grown in containers on shelves. Well-watered and water restriction conditions were applied. The peat matric potential, radiation, temperature and humidity were continuously recorded, while R s was measured and transpiration was assessed every half-hour from 8:00 am to 8:00 pm 10, 11, 12, 14, and 16 weeks after planting. The resulting model was first validated against experimental measurements during the twelfth week of the experiment. It displayed good correlations for both the instantaneous data and integrated total transpiration. Different scenarios of irrigation reduction (frequency x volume) were tested and the results indicated real potential for water use reduction. Indeed, by reducing water application by 50% and by applying one irrigation per day, transpiration was not affected.


      PubDate: 2016-07-17T15:06:15Z
       
  • Agricultural robots for field operations: Concepts and components
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Avital Bechar, Clément Vigneault
      This review investigates the research effort, developments and innovation in agricultural robots for field operations, and the associated concepts, principles, limitations and gaps. Robots are highly complex, consisting of different sub-systems that need to be integrated and correctly synchronised to perform tasks perfectly as a whole and successfully transfer the required information. Extensive research has been conducted on the application of robots and automation to a variety of field operations, and technical feasibility has been widely demonstrated. Agricultural robots for field operations must be able to operate in unstructured agricultural environments with the same quality of work achieved by current methods and means. To assimilate robotic systems, technologies must be developed to overcome continuously changing conditions and variability in produce and environments. Intelligent systems are needed for successful task performance in such environments. The robotic system must be cost-effective, while being inherently safe and reliable—human safety, and preservation of the environment, the crop and the machinery are mandatory. Despite much progress in recent years, in most cases the technology is not yet commercially available. Information-acquisition systems, including sensors, fusion algorithms and data analysis, need to be adjusted to the dynamic conditions of unstructured agricultural environments. Intensive research is needed on integrating human operators into the system control loop for increased system performance and reliability. System sizes should be reduced while improving the integration of all parts and components. For robots to perform in agricultural environments and execute agricultural tasks, research must focus on: fusing complementary sensors for adequate localisation and sensing abilities, developing simple manipulators for each agricultural task, developing path planning, navigation and guidance algorithms suited to environments besides open fields and known a-priori, and integrating human operators in this complex and highly dynamic situation.


      PubDate: 2016-07-17T15:06:15Z
       
  • Integration of visible branch sections and cherry clusters for detecting
           cherry tree branches in dense foliage canopies
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Suraj Amatya, Manoj Karkee
      To minimise the demand for seasonal workers in sweet cherry production, there is a need to develop automated harvesting systems. The first step in automating a shake-and-catch type harvesting system is to develop a machine vision system for detecting tree branches and localising shaking points in those branches. In this study, an image processing algorithm was developed to detect branches of cherry trees using segmentation of branch and cherry pixels. Firstly, partially visible branch segments within the tree canopies were connected using morphological features of the segments to form whole branches. Then, the positions of cherry clusters in the canopy were used as an indication to detect branch sections that were occluded by cherries and leaves. Different cherry clusters were grouped together based on their spatial location and distance between them. Branch equations were then defined through those cherry clusters using minimum residual criteria. Overall, 93.8% branches were detected in a Y-trellis fruiting wall cherry orchard, with 55.0% of branches detected using only branch pixels and 38.8% additional branches detected using cherry clusters. The method resulted in a total of 12.4% of false positive detection. The results showed that branch detection accuracy can be substantially improved by integrating cherry location information with the location of segments of partially visible branches. This study has shown the potential of machine vision systems to detect cherry tree branches in full foliage season, which is highly promising for the development of automated sweet cherry harvesting systems.


      PubDate: 2016-07-17T15:06:15Z
       
  • Soil physical property estimation from soil strength and apparent
           electrical conductivity sensor data
    • Abstract: Publication date: Available online 16 July 2016
      Source:Biosystems Engineering
      Author(s): Yongjin Cho, Kenneth A. Sudduth, Sun-Ok Chung
      Proximal soil sensing is an attractive approach for quantifying soil properties, but many currently available sensors do not respond to a single soil property. For example, soil strength and apparent electrical conductivity (ECa) sensor measurements are significantly affected by soil texture, bulk density (BD), and water content (WC). The objective of this study was to explore the potential for estimating soil texture, BD, and WC using combinations of sensor-based soil strength and ECa data obtained from sites with varying soil physical properties. Data collected from three research sites in Missouri included on-the-go horizontal soil strength at five depths up to 0.5 m on a 0.1-m interval, cone index measurements at the same depths, ECa measured by a Veris 3100, and depth-dependent, laboratory-determined soil properties. An ECa model inversion approach was used to generate layer EC values corresponding to the depth increments of the other variables. Fits of models using EC to estimate WC were variable (R2 = 0.31–0.79). Best fitting BD estimation models (R2 = 0.11–0.55) generally included EC, but soil strength was included in fewer than half of the models. BD model fits were improved considerably by adding lab-measured WC to the model (R2 = 0.30–0.86), suggesting the need for a WC sensor. Soil clay texture fraction models based on EC and WC fit well (R2 = 0.80–0.93). This study showed the potential of combining data from multiple mobile proximal sensors to estimate important soil physical properties.


      PubDate: 2016-07-17T15:06:15Z
       
  • Assessment of soil properties in situ using a prototype portable MIR
           spectrometer in two agricultural fields
    • Abstract: Publication date: Available online 5 July 2016
      Source:Biosystems Engineering
      Author(s): Wenjun Ji, Viacheslav I. Adamchuk, Asim Biswas, Nandkishor M. Dhawale, Bharath Sudarsan, Yakun Zhang, Raphael A. Viscarra Rossel, Zhou Shi
      Mid-infrared (MIR) soil spectroscopy has shown applicability to predict selected properties through various laboratory studies. However, reports on the successful use of MIR instruments in field conditions (in situ) have been limited. In this study, a small portable prototype MIR (898–1811 cm−1) spectrometer was used to collect soil spectra from two agricultural fields (predominantly organic and mineral soils). Both fields were located at Macdonald Campus of McGill University in Ste-Anne-de-Bellevue, Quebec, Canada. In each of the 120 predefined field locations, in situ spectroscopic measurements were repeated three times and one representative soil sample was analyzed following conventional laboratory procedures. For every soil property, a field-specific partial least squares regression (PLSR) model was developed and evaluated using a leave-one-out cross-validation routine. Each soil property was evaluated in terms of the accuracy and reproducibility of model predictions. Among tested soil properties, soil organic matter, water content, bulk density, cation exchange capacity (CEC), Ca and Mg yielded higher model performance indicators (R2 > 0.50 and RPD > 1.40) as compared to soil pH, Fe, Cu, phosphorus, nitrate-nitrogen, K or Na. In most instances, the error estimate representing the prediction reproducibility was found to be as high as 50% of the overall prediction error. This was due to the combination of optical and electrical noise and soil micro-variability causing soil spectra representing the same field location to yield different predictions.


      PubDate: 2016-07-08T23:01:51Z
       
  • Editorial Board
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148




      PubDate: 2016-07-08T23:01:51Z
       
  • Experiments and discrete element method simulations of distribution of
           static load of grain bedding at bottom of shallow model silo
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Józef Horabik, Piotr Parafiniuk, Marek Molenda
      The influences of a filling method, seed size and seed aspect ratio on the radial distribution of the vertical pressure at the bottom of a shallow model silo were studied. Two filling methods were applied: central and circumferential. Seeds of five varieties were used: horse bean (Vicia faba), field pea (Pisum sativum), wheat (Triticum), vetch (Vicia) and rapeseed (Brassica napus). The vertical pressure at the bottom was influenced by the filling methods and seed size. A significant dip in the vertical pressure near the centre of the silo radius was observed in each experimental case except the rapeseed case. Discrete element method (DEM) simulations confirmed the impact of the filling methods on the pressure distribution. The pressure increased with increasing radius for central filling and decreased with increasing radius for circumferential filling. DEM simulations of filling with higher particle kinetic energies produced the greatest vertical pressures near the centre of the silo radius, whereas the lowest values were located close to the silo centre and wall.
      Graphical abstract image

      PubDate: 2016-07-08T23:01:51Z
       
  • In-situ plant hyperspectral sensing for early detection of soybean injury
           from dicamba
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Yanbo Huang, Lin Yuan, Krishna N. Reddy, Jingcheng Zhang
      Drift of dicamba onto non-target crops is a major concern because it is highly active on susceptible crops even at low doses. Early detection of crop injury is critical in crop management. A field study was conducted to determine spectral characteristics of soybean (Progeny P4819LL) treated with dicamba. Drift deposition of dicamba was simulated by direct application at 0.05 to 1.0 times of the recommended label rate (0.56 kg [ai] ha−1) to soybean at the 5- to 6-trifloliolate leaf stage, approximately 6 weeks after planting. The canopy spectral measurements were taken at 24, 48, and 72 h after treatment (HAT) using a portable spectroradiometer in the 325–1075 nm spectral range on 3 randomly selected plants within each plot with device optimisation and data calibration. The results indicated that it was difficult to clearly differentiate the dose response of soybean to different dicamba spray rates within 72 HAT. Regardless of spray rates the soybean treated with dicamba could be clearly differentiated from untreated soybean from 24 to 72 HAT through spectral vegetation index analysis with anthocyanin reflectance and photochemical reflectance indices with accuracies at 24, 48, and 72 HAT ranging from 76 to 86%. Simulated dicamba drift injured soybean and reduced its yield by 71 and 90% at 0.05 and 0.1 times recommended rate, respectively. This study demonstrated that hyperspectral remote sensing has a potential in early detection of soybean injury from exposure to off-target dicamba drift at sub lethal rates in the field.


      PubDate: 2016-07-08T23:01:51Z
       
  • A mobile, in-situ soil bin test facility to investigate the performance of
           maresha plough
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Solomon Gebregziabher, Karel De Swert, Wouter Saeys, Herman Ramon, Bart De Ketelaere, Abdul M. Mouazen, Kindeya Gebrehiwot, Jozef Deckers, Josse De Baerdemaeker
      Ethiopia is well known for its use of an ard plough dating from antiquity – maresha – which fractures and disturbs the soil. However, hardly any notable progress of experimental research on this animal drawn tillage tool in the field has been made. The attendant problems in current practise are soil-maresha interaction, viz., uneven oxen strength along with different pace of walking, uncontrolled implement behaviour, and field conditions. Taking stock of the experimental research on animal drawn tillage tools in general, most of the documented works on the dynamics of the interaction between soil and animal drawn tillage tools tend to rely on trial-and-error based on factors mainly based on experience and cultural context. As such, no research tailored to systematically handle the link between maresha plough and soil bin experiments exists. To this aim, this study developed a mobile in-situ soil bin facility in which the system was calibrated, tested, and evaluated under outdoor experimental conditions, wherein online measurements of draught, speed, and depth of tillage were carried out. The insights and observations gained from the experimentation were discussed and reported in terms of smooth run, overload, cyclic forces, zero speed with minimal force, stoppage, speed measurement with no force, force measurement with no speed, and low speed with low force.


      PubDate: 2016-07-01T18:28:50Z
       
  • Methodology for designing accelerated structural durability tests on
           agricultural machinery
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Dimitris S. Paraforos, Hans W. Griepentrog, Stavros G. Vougioukas
      Structural durability assessment is one of the last stages before an agricultural machine prototype reaches the market. Accelerated structural testing (AST) aims at reducing the time and resources required for this stage. According to existing AST methodologies, strain measurements are used to characterise machine loads under real-world operating conditions, and calculate resulting accumulated fatigue damages. An operation profile is defining the conditions to be monitored but also the target damages of the accelerated testing. Next, rainflow cycles are extrapolated to include non-measured high-amplitude loads. Finally, the machine prototype travels on suitable proving grounds to replicate real-world service loads. The number of laps required to reach the target damage values is the result of optimisation, given the fatigue damages accumulated during each lap. In this paper the above AST methodology was implemented on a four-rotor swather, which is an agricultural implement that drastically changes structure configuration during its working life, depending on its operating mode. Furthermore, recognising the fact that the damage accumulated during each lap varies, automated test facilities were utilised, and Monte-Carlo sensitivity analysis was introduced as part of the AST methodology, to study the effects of damage-per-lap variance on the required numbers of laps calculated via optimisation. When average values were used for lap damages, the total testing time was 1228 h with an acceleration factor of 3.3. However, conservative test design using the 99.9th percentile of the testing time simulation results, required 7.1% longer testing time, leading to a lower acceleration factor equal to 3.1.


      PubDate: 2016-07-01T18:28:50Z
       
  • Comparison of CO2- and SF6- based tracer gas methods for the estimation of
           ventilation rates in a naturally ventilated dairy barn
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Nadège Edouard, Julio Mosquera, Hendrik J.C. van Dooren, Luciano B. Mendes, Nico W.M. Ogink
      Livestock production is a source of numerous environmental problems caused by pollutant gas emissions. In naturally ventilated buildings, estimating air flow rate is complicated due to changing climatic conditions and the difficulties in identifying inlets and outlets. To date no undisputed reference measurement method has been identified. The objective of this paper was to compare CO2- and SF6-based tracer gas methods for the estimation of ventilation rates ( V R C O 2 vs. V R S F 6 ) in naturally ventilated dairy barns both under conventional and very open ventilation situations with different spatial sampling strategies. Measurements were carried out in a commercial dairy barn, equipped with an injection system for the controlled release of SF6, and measurement points for the monitoring of SF6 and CO2 concentrations to consider both horizontal and vertical variability. Methods were compared by analysing daily mean V R C O 2 / V R S F 6 ratios. Using the average gas concentration over the barn length led to more accurate ventilation rates than using one single point in the middle of the barn. For conventional ventilation situations, measurements in the ridge seem to be more representative of the barn average than in the middle axis. For more open situations, both V R C O 2 and V R S F 6 were increased, V R C O 2 / V R S F 6 ratios being also more variable. Generally, both methods for the estimation of ventilation rates gave similar results, being 10–12% lower with the CO2 mass balance method compared to SF6 based measurements. The difference might be attributed to potential bias in both methods.


      PubDate: 2016-06-26T18:04:16Z
       
  • Non-destructive measurement of nitrogen status of leafy ornamental
           cuttings by near infrared reflectance spectroscopy (NIRS) for assessment
           of rooting capacity
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Dieter Lohr, Peter Tillmann, Siegfried Zerche, Uwe Druege, Thomas Rath, Elke Meinken
      An adequate nitrogen supply to stock plants is a well-known key factor in adventitious root formation of herbaceous ornamental cuttings. Both slight deficiency and luxury amount of nitrogen in the tissue can impair rooting. Due to a lack of fast, cheap and reliable analytical methods, parameters characterising the nitrogen status of cuttings are not used as quality indicators. Near infrared reflectance spectroscopy (NIRS) might bridge this gap, especially if sample preparation such as drying or grinding is avoided. NIR spectra of intact chrysanthemum and pelargonium cuttings were taken and partial least square regression models were developed for various nitrogen fractions as well as for total nitrogen. Calibration equations with high prediction performance were developed for insoluble, organic and total nitrogen (R2 > 0.8). Calibration models for various soluble nitrogen fractions were at least suitable for a rough screening (R2 > 0.6). In a second experiment, calibration models were extended to poinsettia, impatiens and osteospermum cuttings by adding a few samples to the calibration data set. Thus, analysing nitrogen status of ornamental cuttings by NIRS might be a valuable tool for optimisation of stock plant cultivation and assessment of rooting capacity of cuttings.


      PubDate: 2016-06-26T18:04:16Z
       
  • Effects of temperature and material on sensing moisture content of
           pelleted biomass through dielectric properties
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Murat Sean McKeown, Samir Trabelsi, Ernest William Tollner
      The production of pelleted biomass represents a significant emerging industry in the United States. Solid biomass can be formed from the waste products of different natural and manufactured products. In this study, the effects of temperature and pellet material type on the dielectric properties were investigated. The resulting information was used to develop temperature- and material-independent moisture prediction equations. Dielectric properties of peanut-hull, pine, and hardwood pellets were measured at microwave frequencies for temperatures between 10 °C and 50 °C and at moisture contents between 4.9% and 16.0%. Further work was performed in investigating the dielectric properties of pine, peanut-hull, and hardwood pellets to determine whether a “unified” calibration for moisture content might be developed. Results showed that a temperature-compensated calibration for moisture content could be developed for different pellet types with standard errors of calibration between 0.50% and 1.04%. In addition, a unified calibration for pine, peanut-hull and hardwood pellets at 20 °C was developed that provides moisture content for the materials with a standard error of calibration between 0.48% and 0.56%.


      PubDate: 2016-06-26T18:04:16Z
       
  • Estimation of the density of pomegranate fruit and their fractions using
           X-ray computed tomography calibrated with polymeric materials
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Ebrahiema Arendse, Olaniyi Amos Fawole, Lembe Samukelo Magwaza, Umezuruike Linus Opara
      The application of microfocus X-ray computed tomography (μCT) with a density calibration with homogenous polymeric materials ranging from 910 to 2150 kg m−3 and its accuracy for differentiating fruit fractions (albedo and arils) and the effects of detecting false codling moth and blackheart disease in pomegranate fruit was investigated. A commercial microfocus X-ray (μCT) system in combination with image analysis techniques was used to generate two-dimensional (2-D) radioscopic images which were reconstructed into three dimensional (3-D) images. Optimum μCT settings were obtained using an isotropic voxel size of 71.4 μm based on a radiation source generated from a voltage of 100 kV with the electric current set at 200 μA. The density of whole pomegranate fruit, its fractions (arils and albedo), false codling moth, and blackheart infected portions were successfully determined within the calibration range. Furthermore, the density of larva moth (9400 ± 40 kg m−3) were found to be significantly (p < 0.0001) lower than whole fruit (1070 ± 20 kg m−3) and fruit fractions (arils 1120 ± 40 kg m−3 and albedo 1040 ± 30 kg m−3). Similarly, the differentiation between healthy and blackheart affected fruit was successfully accomplished. The density of healthy fruit was significantly (p < 0.0001) higher (1070 ± 20 kg m−3) than that of fruit affected by blackheart which ranged from 870 to 1000 kg m−3. The results thus demonstrated that X-ray μCT with associated algorithm can be used to accurately detect and quantify internal defects caused by false codling moth and blackheart disease in pomegranate fruit.


      PubDate: 2016-06-22T17:52:01Z
       
  • Editorial Board
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147




      PubDate: 2016-06-22T17:52:01Z
       
  • Thank you to reviewers
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147




      PubDate: 2016-06-22T17:52:01Z
       
  • Detection of cucumber green mottle mosaic virus-infected watermelon seeds
           using a near-infrared (NIR) hyperspectral imaging system: Application to
           seeds of the “Sambok Honey” cultivar
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Hoonsoo Lee, Moon S. Kim, Hyoun-Sub Lim, Eunsoo Park, Wang-Hee Lee, Byoung-Kwan Cho
      The cucurbit diseases caused by cucumber green mottle mosaic virus (CGMMV) have led to a serious problem to growers and seed producers because it is difficult to prevent spreading through pathogen-infected seeds. Conventional detection methods for infected seeds such as biological, serological, and molecular measurements are not practical for measuring entire samples due to their destructive nature, and time, and cost issues. For this reason, it is necessary to develop a rapid and non-destructive novel technique for detecting seeds infestation. A near-infrared (NIR) hyperspectral imaging system was used to discriminate virus-infected seeds from healthy seeds with partial least square discriminant analysis (PLS-DA) and least square support vector machine (LS-SVM). The classification accuracy for virus-infected watermelon seeds were 83.3% with the best model, demonstrating the potential of NIR hyperspectral imaging for detection of virus-infected watermelon seeds.


      PubDate: 2016-06-18T18:00:44Z
       
  • Detecting tomatoes in greenhouse scenes by combining AdaBoost classifier
           and colour analysis
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Yuanshen Zhao, Liang Gong, Bin Zhou, Yixiang Huang, Chengliang Liu
      Despite the rapid development of agricultural robotics, a lack of access to automatic fruit detection and precision picking is limiting the commercial application of harvesting robots. An algorithm for the automatic detection of ripe tomatoes in greenhouse was developed for a simple machine vision system. The images of tomato planting scenes were captured by a colour digital camera, and most of the ripe tomatoes were correctly recognised using the proposed algorithm. The proposed tomato detection approach worked in two steps: (1) by extracting the Haar-like features of grey scale image and classifying with the AdaBoost classifier, the possible tomato objects were identified; (2) the false negatives in the results of classification were eliminated using average pixel value (APV) based colour analysis approach. Comparative test results showed that the C style of Haar-like features and I component image were optimum in the proposed algorithm. The results of validation experiments show that combination of AdaBoost classification and colour analysis can correctly detect over 96% of ripe tomatoes in the real-world environment. However, the false negative rate was about 10% and 3.5% of the tomatoes were not detected.


      PubDate: 2016-06-14T13:10:36Z
       
  • Front end loader with automatic levelling for farm tractors
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Juan I. Latorre-Biel, Ignacio Arana, Tomás Ballesteros, Jesús M. Pintor, José R. Alfaro
      One of the most commonly used accessories in multiple applications with farm tractors is the front end loader. There is a broad variety of loaders that can offer a range of possibilities and advantages to the operator. Depending on the task to be developed, the functionality that the operator requests from the loader may be different. Nevertheless, in order to avoid significant loss of product during transport, in most applications it is desirable for the loader to be level throughout its movement. In this paper, a new methodology for achieving a high quality levelling is described. This methodology, when compared to the alternative options that can be found in the market, presented favourable features. The proposed methodology could be implemented at affordable cost by using a reduced set of inexpensive components and can be applied to both new and old tractors.


      PubDate: 2016-06-14T13:10:36Z
       
  • Compression and relaxation properties of selected biomass for briquetting
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Lei Guo, Decheng Wang, Lope G. Tabil, Guanghui Wang
      Compression and relaxation properties of selected biomass for briquetting (barley, oat, canola and wheat straw) were investigated to determine the correlation with variables (pressure, particle size (hammer mill screen size) and moisture contents). The applied pressure ranged from 7.03 to 14.06 MPa. Three hammer mill screen sizes (19.05, 25.40 and 31.75 mm) were used to grind the biomass samples. The ground biomass materials were conditioned to moisture contents of 9%, 12% and 15% (w.b.). The results indicated that the compact density of biomass increased with increasing pressure and moisture content. The relaxation properties of selected materials were affected by the set variables. Biomass materials had a higher stress relaxation speed with higher applied pressure and lower moisture content.


      PubDate: 2016-06-14T13:10:36Z
       
  • Droplet characterisation of a complete fluidic sprinkler with different
           nozzle dimensions
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Junping Liu, Xingfa Liu, Xingye Zhu, Shouqi Yuan
      The complete fluidic sprinkler (CFS) has the advantages of a simple structure and the ability to work well at a lower nozzle pressures. CFS is a gas–liquid fluidic sprinkler, whose driving moment is achieved by a flow reaction as a result its droplet characteristics differ from those of conventional sprinklers. To study the droplet characteristics of the CFS, droplet diameter and velocity were measured using a Thies Clima laser precipitation monitor (TCLPM). Statistical analysis was conducted on the droplet size distribution using a volume-weighted method and droplet velocity was analysed using a number-weighted method. The results showed that volume mean droplet diameter and volume medium diameter increased with the distance from the nozzle and decreased with the nozzle size. The frequency of droplets with a diameter <3 mm increased with the working pressure. The number of larger droplets decreased with pressure and increased with the nozzle size when the pressure was 0.25, 0.30, or 0.35 MPa. A lognormal distribution model was used to evaluate the drop diameter distribution for each observed distance. With increasing pressure, the slope of the cumulative volume frequency droplet size curve at different distances from the nozzle decreased, and the distribution followed the trend of a Boltzmann function distribution. Droplet velocity increased with the droplet diameter but was not significantly influenced by the nozzle pressure. The results may provide a basis for further systematic research on the CFS.


      PubDate: 2016-06-14T13:10:36Z
       
  • Methodology to analyse farm tractor idling time
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Daniela Perozzi, Michele Mattetti, Giovanni Molari, Eugenio Sereni
      Actual in-service damage to tractor engines could be different from that predicted according to other estimates due to the difficulties in evaluating all the information necessary to completely define the mission profile. Among the different parameters which could be measured or estimated, the idling duration is one of the most influential factors in the calculation of in-service damage. In this paper, a methodology to estimate the idling time from signals recorded through a data logger interfaced to the vehicle-bus is proposed. Through statistical methods, the idling duration distribution was identified for a fleet of 61 New Holland T9 farm tractors used in Europe and in North America. Starting from these distributions the percentiles have been estimated. The recorded values of idling duration range from 5% up to 50% and the average value is about 20% of the tractor life. Furthermore, 97.5% of the analysed tractors run under idling condition for greater than 10% of the whole life of the machine. All tractors have made at least a stop shorter than 1920 s, while not all have made a stop longer than 1920 s. From the analysis, tractors located in areas with extreme temperatures have run under idling conditions for a longer time to keep the cab comfortable or to maintain the engine on temperature. This data confirms the importance to considering the geographical distribution of the machines and the necessity of performing a wide acquisition campaign to define the tractor mission profile.


      PubDate: 2016-06-14T13:10:36Z
       
  • Field phenotyping system for the assessment of potato late blight
           resistance using RGB imagery from an unmanned aerial vehicle
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Ryo Sugiura, Shogo Tsuda, Seiji Tamiya, Atsushi Itoh, Kentaro Nishiwaki, Noriyuki Murakami, Yukinori Shibuya, Masayuki Hirafuji, Stephen Nuske
      In tests for field resistance of potato (Solanum tuberosum L.) to late blight, crop scientists rate the disease severity exclusively using visual examinations of infections on the leaves. However, this visual assessment is generally time-consuming and quite subjective. The objective of this study was to develop a new estimation technique for disease severity in a field using RGB imagery from an unmanned aerial vehicle (UAV). For the assessment of disease resistance of potatoes a test field was designed that consisted of 262 experimental plots on which various cultivars and lines were planted. From mid-July to mid-August in 2012, conventional visual assessment of disease severity was conducted while 11 aerial images of the field were obtained. The disease severity was estimated using an image processing protocol developed in this study. This estimation method was established so that the error of the severity estimated by image processing was minimal when compared with the visual assessment. Comparing the area under the disease progress curves (AUDPCs) calculated from the visual assessment and time series of images, the coefficient of determination was 0.77. A further experiment was conducted to validate the developed method. Eleven images of a field planted the following year were taken, and the resulting coefficient of determination was 0.73. The breeders concluded that these correlations were acceptable and that the UAV image acquisition and the disease severity estimation from the image were more efficient than the conventional visual assessments. Therefore, the developed technique based on aerial imagery allows high throughput, objective, and precise phenotyping with regard to field resistance to potato late blight.


      PubDate: 2016-06-14T13:10:36Z
       
  • Remote detection of the swarming of honey bee colonies by single-point
           temperature monitoring
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Aleksejs Zacepins, Armands Kviesis, Egils Stalidzans, Marta Liepniece, Jurijs Meitalovs
      Precision Beekeeping (or Precision Apiculture) aims to help beekeepers monitor bee colonies remotely and identify different colony states including deviant behaviour. One monitoring target is the remote identification of bee colony swarming since this is one of the factors that can significantly reduce profitability. To identify temperature dynamics and its patterns for swarming detection, ten colonies were constantly monitored for four months from 1 May to 31 August 2015. Nine swarms were observed during experiments. During the warm-up stage, in the last 10–20 min before take-off, a temperature rise by 1.5–3.4 °C from typical range 34–35 °C to range 37–38 °C was registered by a temperature sensor placed above the polyethylene foil covering the upper hive body under the pillow. For all swarming events it was common that a bee colony needs a relatively small amount of time (from 8 to 20 min) to warm up before take-off. It was concluded that a single temperature sensor above the bee nest combined with a proposed decision support algorithm can be used for automatic remote detection of swarming at take-off stage.


      PubDate: 2016-06-14T13:10:36Z
       
  • Effects of an extended c-phase on vacuum conditions in the milking cluster
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Franziska E. Bluemel, Pascal E. Savary, Matthias E. Schick
      The objective of this study was to examine how a prolonged closing phase in the pulsation chamber cycle would affect vacuum conditions on the teat and liner movement. Wrong vacuum conditions and liner movements, controlled by pulsators, could cause discomfort on the teats and have negative effects on udder health. Therefore, 18 focal dairy cows were randomly subjected to two types of pulsation chamber cycles (treatments A and B) for 12 milkings in a low-line 2 × 3 auto tandem milking parlour. The treatments differed in the duration of closing and closed phases (c- and d-phases, respectively). In treatment A, the c-phase was 70 ms and the d-phase was 330 ms, whereas in treatment B, the c-phase lasted 130 ms and the d-phase 270 ms. Using a vacuum measuring device, measurement series with 5 s intervals were conducted during three phases of the milking process: the plateau phase, the decreasing phase, and the over-milking phase. Differences between the treatments were detected in the total pressure per cycle and maximum vacuum on the teat-end. Treatment B showed on average a 1 kPa s lower total pressure per cycle than treatment A, whereas values of maximum vacuum at the teat-end were on average 0.2 kPa higher in Treatment B than A. Further, differences could be detected between the three phases during the milking proceedings, showing that the observed parameters were related to the milk flow rate. The results indicate that treatment B might be gentler and more comfortable for dairy cows, which will be established next.


      PubDate: 2016-06-14T13:10:36Z
       
  • An experimental system for extraction of pectin from orange peel waste
           based on the o-core transformer structure
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Na Yang, Yamei Jin, Yaoqi Tian, Zhengyu Jin, Xueming Xu
      An experimental system based on the o-core transformer structure was established and used to extract pectin from orange peel waste. Unlike other electric-field-assisted techniques, it avoids the use of powered electrodes. The acidic solvent acts as the secondary coil connected to a purpose-made glass chamber which forms a closed loop. Then the induced electric field in the system appears to be under the influence of alternating magnetic flux based on Faraday's law of induction. We found that an increase in the excitation voltage causes enhancement of the pectin yield. Increasing frequency from 20 to 200 kHz had a negative impact on pectin yield partially due to the increased impedance of the primary coil. The ionic conduction was enhanced at the same excitation voltage since there are more free ions in the mixture at lower pH. This means that a lower impedance in the mixture is conducive to extraction. This multidisciplinary technique combines the transformer concept with the electric-field-assisted process, thus providing a reference for the application into agricultural by-products treatment.


      PubDate: 2016-06-14T13:10:36Z
       
  • Temperature distribution in a packed-bed of canola seeds with various
           moisture contents and bulk volumes during radio frequency (RF) heating
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Daeung Yu, Bijay L. Shrestha, Oon-Doo Baik
      This research investigated temperature distribution in a packed-bed of canola seeds at various moisture contents (5%, 7%, 9%, and 11% wet weight basis) and bulk volumes (small – 196.3 cm3, medium – 1766 cm3, and large – 6503 cm3) during RF heating (1.5 kW, 27.12 MHz). The samples were contained in RF-transparent cylindrical and rectangular sample holders. The RF exposure time required to reach a specific temperature decreased with seed moisture content (MC). The hottest spot (80 °C) was detected at the geometric center of the small and large volume canola seeds, but away from the geometric center and towards the edge of the medium volume canola seeds due to the edge effect. The temperature uniformity index values indicated that the most uniform RF heating was observed in the medium volume canola seeds in spite of the edge effect. The highest temperatures occurred between the middle and outer regions of the medium volume canola seeds. RF heating and thermal imaging were used to obtain temperature profiles for 2% agar gels in small, medium and large holders. The temperature profiles for the gels supported the observations made for the canola seeds.


      PubDate: 2016-06-14T13:10:36Z
       
  • Multi-tree woody structure reconstruction from mobile terrestrial laser
           scanner point clouds based on a dual neighbourhood connectivity graph
           algorithm
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Valeriano Méndez, Joan R. Rosell-Polo, Miquel Pascual, Alexandre Escolà
      A process is presented for the vector reconstruction of fruit plantations based on the model developed by Verroust and Lazarus. To solve occlusion problems, the use of a dual graph of local and extended connectivity is proposed. The process allows vegetation variables such as the length and volume of the ligneous structure to be measured, enabling studies such as intensity of pruning operations. The process has been tested against simulated models and real trees with different training systems: open-vase system (peach trees) and central leader hedgerow system (pear trees). The cost of the algorithm will be given by the cost of the implementation of Dijkstra's algorithm, which in its standard version is of potential ( O ( n 2 ) ). Algorithm accuracy was checked against point clouds of virtual trees. The reconstruction was also applied before and after a pruning operation of real trees to enable a study of the evolution of the vegetation indices. Results showed the algorithm to be suitable for multi-tree reconstruction of both central leader and open-vase training systems.


      PubDate: 2016-06-14T13:10:36Z
       
  • Dust explosions in an experimental test silo: Influence of length/diameter
           ratio on vent area sizes
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Alberto Tascón, Álvaro Ramírez-Gómez, Pedro J. Aguado
      Vented dust explosion tests have been conducted in an experimental test silo in order to analyse the effect of the length/diameter ratio (L/D). The modular design of the silo permitted the assembling of four different vessels with different geometries. The tests were carried out with wheat flour and maize starch, using three different vent area sizes. The silo was equipped with instrumentation which recorded the pressure generated by the explosion at various points in the silo, as well as the instant when the vent panel opened. The length/diameter ratio has been included in the empirical correlations currently employed in standards EN 14491 and NFPA 68 for calculating the size of vents. However, there are marked differences between the two standards when applied to certain situations, in part due to a different vent area correction for slenderness. The results obtained in this experimental test programme were compared with the standards, and indicated the advisability of applying an increase in vent area in elongated vessels when L/D > 1, as stated in EN 14491. However, this same standard appears to apply an excessively severe correction in some situations.
      Graphical abstract image

      PubDate: 2016-06-14T13:10:36Z
       
  • An adaptively controlled modified atmosphere container system for fresh
           produce
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Ji Hye Lee, Duck Soon An, Jae Min Song, Yong Bae Jung, Dong Sun Lee
      Time-variable open/close cycles of a gas diffusion tube may serve as a means to supply the desired gas transfer to attain a beneficial modified atmosphere (MA) in fresh produce containers. Because the produce respiration contributing to the atmosphere modification changes over time, adoption of real-time respiration in the open/close control of the tube may be an innovative tool to maintain the container atmosphere. An adaptive control of the tube responding to the real-time respiration of fresh produce was developed based on a simplified O2 mass balance to generate and maintain the desired MA for the fresh produce. Here, the O2 concentration change in the initially closed container before reaching the target value was used to calculate the respiration rate to determine the starting value of the opening ratio of the cycle time and the average O2 concentration of each cycle after reaching the target value once was used in the mass balance relationship to update the opening ratio for the next cycle. The developed MA container system could attain the targeted O2 concentrations and the expected desirable CO2 concentrations for blueberries and spinach at steady state, helping to preserve their quality.
      Graphical abstract image

      PubDate: 2016-06-14T13:10:36Z
       
  • Parameters and contact models for DEM simulations of agricultural granular
           materials: A review
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Józef Horabik, Marek Molenda
      The discrete element method has been in development since 1970s and has recently found practical application in simulations of granular assemblies to investigate natural phenomena as well as a design tool for technology. Agriculture and food engineering harvests, stores, handles or processes an enormous amount of particulate material of biological origin. Unlike mineral or plastic granular materials, these materials are usually hygroscopic and change their mechanical properties through the absorption of moisture. Information regarding material properties of granular materials of biological origin is insufficient, uncertain and dispersed across various journals. This review presents a collection of material properties that are useful for discrete element method, DEM, simulations gathered from contributions of various laboratories around the world. Peculiar behaviour of materials of biological origin requires not only a specific approach in determining the parameters but also a specific setup of simulations. This article presents findings that appear efficient at the current stage of development of granular mechanics and DEM simulations. Emerging trends in the evolution of DEM are also presented.
      Graphical abstract image

      PubDate: 2016-05-15T13:17:54Z
       
  • A CFD study on improving air flow uniformity in indoor plant factory
           system
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Ying Zhang, Murat Kacira, Lingling An
      Indoor plant factories are one of the alternative ways to meet the demands of food production for the increased urban dwellers. It enables growers to grow food crops consistently and locally with high quality. In an indoor plant factory, a forced convection based ventilation and circulation system is used to control the growing environment and maintain climate uniformity. Lettuce is a common leafy crop grown in indoor plant factories and an improper design could cause the tip burn of lettuces which usually occurs at inner and newly developing leaves with low transpiration rate due to the existence of a stagnant boundary layer under high transpiration demand. A three-dimensional computational fluid dynamics (CFD) model was developed and validated through simulating the growing environment in a single shelf production system. An improved air circulation system was designed and proposed to help providing a dynamic and uniform boundary layer which could help preventing tip burn occurrences in lettuce production. A perforated air tube with three rows of air jets was designed to provide vertical air flow down to the crop canopy surface. Four cases with the perforated air tubes were compared with a control treatment. The results indicated that the case with two perforated air tubes was able to provide an average air velocity of 0.42 m s−1 with a coefficient of variation of 44%, which was recommended as the optimal design of air circulation system among four cases in this study.


      PubDate: 2016-05-15T13:17:54Z
       
  • Comparison of methods for estimating the carcass stiffness of agricultural
           tyres on hard surfaces
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Paula A. Misiewicz, Terence E. Richards, Kim Blackburn, Richard J. Godwin
      Loading soil via pneumatic tyres is a major cause of compaction of agricultural soils, which causes damage to the soil-water-air-plant system. The loads applied to the soil and the resulting pressure influences the degree of soil compaction. This study was conducted to determine an effective method to measure the pressure distribution under a selection of pneumatic agricultural tyres. This was conducted initially on a non-deformable surface; a later study will consider pressures within the subsoil. From this the tyre carcass stiffness was determined and methods to predict carcass stiffness were evaluated. Tyre carcass stiffness is defined as an equivalent pressure resulting from the stiffness of the tyre carcass. In order to estimate the carcass stiffness of tyres a number of approaches were considered including: (i) footprint area, (ii) tyre load – deflection, (iii) pressure mapping and (iv) tyre manufacturer's specification methods. Carcass stiffness values obtained from the footprint area method gave results significantly lower (30–40%) than those obtained using the pressure mapping system. The method based on the tyre load – deflection characteristics was found to give a better estimation of the tyre carcass stiffness of the smooth rather than the treaded tyre. The technique of using the tyre manufacturer's specification data, where the estimation of the tyre carcass stiffness was calculated using the theoretical load that the tyre could support at zero inflation pressure, produced estimates that were within ±20% of the mean carcass stiffness determined using the pressure mapping system.


      PubDate: 2016-05-15T13:17:54Z
       
  • Effects of hydraulic retention time and organic loading rate on
           performance and stability of anaerobic digestion of Spirulina platensis
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Natthiporn Aramrueang, Joshua Rapport, Ruihong Zhang
      The effects of hydraulic retention time (HRT) and organic loading rate (OLR) were investigated during a continuous anaerobic digestion of Spirulina platensis. The continuous process operated with varying HRT (10–25 d) and OLR (1.0–4.0 [g VS] l−1 d−1) resulted in the biogas and methane yields in the range of 0.276–0.502 l [g VS]−1 and 0.163–0.342 l [g VS]−1, respectively. The methane yield decreased with the increase in OLR and the reduction in HRT. Maximum methane yield of 0.342 l [g VS]−1 was produced when the digester was operated at OLR of 1.0 [g VS] l−1 d−1 and 25 d HRT. A mathematical model was developed from a kinetic study for predicting methane yield as the function of HRT during a continuous digestion. The model performed well at OLR lower than 2.0 [g VS] l−1 d−1, at which the digestion was not limited by high ammonia levels or volatile fatty acid accumulation.


      PubDate: 2016-05-15T13:17:54Z
       
  • Detection of fungal infection and Ochratoxin A contamination in stored
           barley using near-infrared hyperspectral imaging
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Thiruppathi Senthilkumar, Digvir S. Jayas, Noel D.G. White, Paul G. Fields, Tom Gräfenhan
      Aspergillus glaucus and Penicillium spp. infections and Ochratoxin A contamination were detected in stored barley using a Near-Infrared (NIR) hyperspectral imaging system. Fungal infected samples and Ochratoxin A contaminated samples were subjected to single kernel imaging every two weeks, and acquired three dimensional image data were transformed into two dimensional data. The two dimensional data corresponding to each fungal infected sample and Ochratoxin A contaminated sample were subjected to principal component analysis (PCA) for data reduction, and to identify significant wavelengths. The significant wavelengths 1260, 1310, and 1360 nm corresponding to A. glaucus, Penicillium spp., and non-Ochratoxin A producing Penicillium verrucosum infected kernels and wavelengths 1310, 1360, and 1480 nm corresponding to Ochratoxin A contaminated kernels were obtained based on the highest principal components (PC) factor loadings. Statistical and histogram features from significant wavelengths were extracted and used as input for linear, quadratic, and Mahalanobis statistical classifiers. Pair-wise, two-class, and six-class classification models were developed to differentiate between sterile and infected kernels. The three classifiers differentiated sterile kernels with classification accuracy of more than 94%, fungal infected kernels with more than 80% at initial periods of fungal infection and attained 100% classification accuracy after four weeks of fungal infection. Ochratoxin A contaminated kernels can be differentiated from sterile kernels with a classification accuracy of 100%. Different periods of fungal infection and different levels of Ochratoxin A contamination were discriminated with a classification accuracy of more than 82%.


      PubDate: 2016-05-09T12:48:52Z
       
  • Design and performance of a direct and continuous ventilation measurement
           system for variable-speed pit fans in a pig building
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Ji-Qin Ni, Daniel Kaelin, Igor M. Lopes, Shule Liu, Claude A. Diehl, Chao Zong
      Manure pit ventilation is a common design in commercial pig-rearing buildings. However, determining accurate pit ventilation rates is technically challenging. A new pit exhaust airflow measurement assembly (PEAMA) was developed to directly and continuously measure airflow rates for tube-mounting variable-speed pit fans. The PEAMA consists of a PVC pipe, a flow straightener, and an impeller anemometer. A laboratory study revealed good linear correlations between the PEAMA signal outputs and the fan rotational speeds (R2 > 0.999). The ventilation rates measured with the PEAMA were calibrated against those with the standardised traverse measurement with a highly linear correlation (R2 > 0.996). In 2011, 24 PEAMA units were installed in twenty-four 250-mm diameter pit fans in a state-of-the-art pig research building. Multi-year field performance showed that the PEAMA greatly improved data quality during pit fan airflow monitoring compared with previously adopted techniques. This system enabled continuous and real-time ventilation outputs to be determined in volume time−1. It was easy to maintain due to the simple design and outdoor installation. The cost of the 24 units accounted for only a small portion of a comprehensive air quality monitoring setup at the pig research building.


      PubDate: 2016-05-09T12:48:52Z
       
  • Navigation of autonomous tractor for orchards and plantations using a
           laser range finder: Automatic control of trailer position with tractor
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Pawin Thanpattranon, Tofael Ahamed, Tomohiro Takigawa
      The autonomous control of a tractor-trailer system in orchards and plantations has frequently been observed for the transportation, loading and unloading of products between plants and trees. The objective of this research was to develop a control algorithm for a single-sensor tractor-trailer navigation system for navigating within a row plantation and travelling between plots. A control scheme for stopping the tractor-trailer for various in-field tasks, such as product loading/unloading using a laser range finder (LRF), is presented. The LRF was used to navigate a full-size autonomous agricultural tractor equipped with a two-wheeled trailer. For ease of operation in narrow rows, a sliding hitch bar (SHB) was developed to control the trailer by adjusting the position of the hitch-point between the tractor and trailer. Compared to the tractor-trailer system driven by human, the control system could navigate the tractor-trailer with the RMS differences of 0.275 m (SD: 0.009 m), 0.373 m (SD: 0.030 m) and 0.518 m (SD: 0.022 m) for wide curve, tight curve and U-turn experimental paths, respectively. The SHB unit also supported the navigation system with wider turn for the trailer than conventional single hitch point about 0.383 m (7.66% of the 5 m path width, SD: 0.028 m), 0.762 m (15.23% of 5 m path width, SD: 0.010 m) and 1.094 m (21.88% of 5 m path width, SD: 0.037 m) for wide curve, tight curve and U-turn experimental paths, respectively. The control system also stopped the tractor-trailer at the specified landmarks. The results show that the navigation of the tractor-trailer was demonstrated with satisfactory accuracy and that the trailer position was controlled by the SHB with a wider turn in the experimental paths. Therefore, this laser-based landmark navigation system, and the SHB unit, can be adopted for different applications of autonomous tractor-trailer systems with controlled trailer positioning.


      PubDate: 2016-05-04T21:57:53Z
       
  • Diagnosis of potassium nutrition level in Solanum lycopersicum based on
           electrical impedance
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Li Jinyang, Li Meiqing, Mao Hanping, Zhu Wenjing
      Potassium (K) is an essential element for crop growth. Tomato has a long growth cycle and large fertiliser requirement; thus, K stress often occurs and degrades crop yield and quality. It is the most suitable method to provide nutrition based on the actual requirement of crop growth. An accurate monitoring and diagnosis of nutrition during crop growth is key to realise a precise nutrient management. Crop K monitoring methods have been developed to improve K fertiliser management, and most of them are based on leaf or canopy optical property measurements. However, sensitivity to environmental interference remains an important drawback of these methods. Electrical impedance has been applied to determine the physiological and nutritional status of plant tissues, but no studies related to plant K contents have been reported. This study aims to evaluate the K nutrition level based on leaf impedance spectroscopy. Five sets of tomato samples with different K contents were grown. Total K content of leaves was determined, and electrical impedance data recorded in a frequency range of 1 Hz to 1 MHz. The measured impedance data were analysed using an equivalent circuit model for cellular tissues. The change rule of equivalent parameters was obtained, and the sensitive impedance spectroscopy characteristics of K nutrition level were extracted. Moreover, the influence of moisture content on impedance measurement is discussed and the prediction model for K content is established. Results show that electrical impedance can be applied to the detection and diagnosis of plant K nutrition status.


      PubDate: 2016-05-04T21:57:53Z
       
  • Identifying multiple plant diseases using digital image processing
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Jayme Garcia Arnal Barbedo, Luciano Vieira Koenigkan, Thiago Teixeira Santos
      The gap between the current capabilities of image-based methods for automatic plant disease identification and the real-world needs is still wide. Although advances have been made on the subject, most methods are still not robust enough to deal with a wide variety of diseases and plant species. This paper proposes a method for disease identification, based on colour transformations, colour histograms and a pairwise-based classification system. Its performance was tested using a large database containing images of symptoms belonging to 82 different biotic and abiotic stresses, affecting the leaves of 12 different plant species. The wide variety of images used in the tests made it possible to carry out an in-depth investigation about the main advantages and limitations of the proposed algorithm. A comparison with other algorithms is also presented, and some possible solutions for the main challenges that still prevent this kind of tool to be adopted in practice.


      PubDate: 2016-05-04T21:57:53Z
       
  • Estimation of carbon-oxide emissions of tractors during operation and
           correlation with the not-to-exceed zone
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Algirdas Janulevičius, Antanas Juostas, Aušra Čiplienė
      The continuing rise in fossil fuel use significantly aggravates global warming problems because of carbon dioxide (CO2) emissions. This article shows a procedure to indirectly obtain data concerning the environmental pollution of a tractor by starting from direct data. The research confirms that qualitative indicators of a tractor's work for an operational period could be identified from a database compiled from engine processors. The average work rate of tractors measured under field conditions, together with the operating time in an engine's work mode, fuel consumption, and CO2 and CO emissions, have been measured. Correlations between CO2 and CO emissions and the NTE (not-to-exceed) zones during a tractor's operational period have also been determined. The study showed that the tractors worked, on average, 51% of the operational period with the engine working modes within the NTE zone. While working in these modes, the tractors consumed approximately 73.4% of the fuel used for the whole operational period, and emitted into the environment approximately 76% of the CO2 and 9.7% of the CO of the emissions of the whole operational period. It was found that there are possibilities to reduce fuel consumption and CO2 and CO emissions during tractor operational periods by improving the tractor's operation by choosing engine work modes in a more rational way.


      PubDate: 2016-05-04T21:57:53Z
       
  • Region-based colour modelling for joint crop and maize tassel segmentation
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Hao Lu, Zhiguo Cao, Yang Xiao, Yanan Li, Yanjun Zhu
      Crop segmentation is a frequently occurring problem for computer vision applications in agriculture. Meanwhile, the fine-grained shape extraction of maize tassels is also an essential step in the detasselling and field-based phenotyping research. However, existing methods are usually dependent on category, which is hard to transfer to other cultivars with different colours. To address this, the goal of this study is to develop a general method that can process different colours simultaneously and that has good flexibility and expandability. Targeting maize, we proposed to segment jointly the crop and maize tassel. In particular, a novel joint segmentation dataset regarding crop and maize tassel (323 images with corresponding manually-annotated ground-truth images) is constructed, hoping that it can serve as a benchmark to facilitate related studies. Technically, a region-based approach that leverages the efficient graph-based segmentation algorithm and simple linear iterative clustering (SLIC) is developed to generate region proposals. Also, we proposed to model colours with ensemble neural networks specific to each intensity, aiming to achieve robustness to illumination. In addition, two simple but effective strategies are devised to accelerate the colour statistics extraction and ensemble model prediction. The effectiveness and efficiency of our method are demonstrated on the two segmentation tasks, respectively. Results show that our method significantly outperforms other state-of-the-art approaches on tassel segmentation, with average precision of 74.3%, and achieves comparable performance of 77.8% on the traditional crop segmentation even with the naivest colour feature. The dataset and source code are made available online.
      Graphical abstract image

      PubDate: 2016-05-04T21:57:53Z
       
  • Does rearing system (conventional vs. organic) affect ammonia emissions
           during the growing and fattening periods of pigs?
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Marko Ocepek, Dejan Škorjanc
      Ammonia emissions from organic (ORG) and conventional (CON) rearing systems in relation to pig growth rate and behaviour were studied. Microclimatic conditions and ammonia concentrations were monitored. Excretory behaviour was recorded in the growing and fattening periods using video cameras. Throughout the experiment, significantly lower ammonia emission was detected in facilities of the ORG pigs (P < 0.001). The differences in ammonia emission may be partially explained as a consequence of lower level of crude protein, lower feed intake and different growth performance of ORG pigs. Urination and defecation indoor (on the slatted and solid floors) were higher in the CON group (P < 0.05). The results of the present study show that the minimum requirements specified in organic legislation are well suited to normal pig excretory behaviour in both growing and fattening stages and provides pigs cleaner indoor space as well as an improved environment for human and pigs, with around 40% of reduced ammonia emission.


      PubDate: 2016-04-29T03:33:16Z
       
  • Investigation of productivity enhancement and biomechanical risks in
           greenhouse crops
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Raziel Riemer, Avital Bechar
      Labour is the single largest cost contributor and main limiting factor to development of the agricultural industry. Manual labour remains a major, essential factor for greenhouse-grown specialty crops. Furthermore, musculoskeletal injuries are prevalent during manual work processes performed in agricultural environments. This study aims to improve work efficiency and productivity and to identify tasks that can cause musculoskeletal injury. Working procedures were characterised using a work-study method, environmental conditions were recorded and a biomechanical analysis of the inspected task was conducted. An innovative measuring system was developed that enables synchronisation and analysis of the manufacturing, biomechanics, workload and environmental data. The study focused on the trellising and harvesting stages of pepper and tomato in greenhouses on two farms located in southwest Israel. We further conducted several experiments in which we changed the working method and assessed the effect on productivity. Another experiment was conducted to test the effect of three different trellising angles (30°, 60°, 90°) on labour and yield in tomato. The results revealed that in tomato, in comparison to current methods, picking 4 fruit per cycle will increase production rate by 17%, leaf removal from the fruit area will increase production rate by 14.4%—up to 40.2%—and the best trellising angle with respect to yield and labour will be 30°. Analysis of biomechanical risk showed that the maximum weight of lifted boxes should not exceed 12 kg, and when picking fruit growing low to the ground, the workers are exposed to medium to high risk of injury.


      PubDate: 2016-04-29T03:33:16Z
       
  • Optimal reservoir sizing in on-demand irrigation networks: Application to
           a collective drip irrigation network in Spain
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Argenis Izquiel, Rocio Ballesteros, Jose M. Tarjuelo, Miguel A. Moreno
      Optimal reservoir sizing in on-demand irrigation networks with a minimum cost was obtained, taking into account the variability of pressure and flow rate demanded by the network during the irrigation season. With this aim, a model called DRODIN (Design of Reservoirs of regulation in On-Demand Irrigation Networks) was developed under a holistic approach. That obtain the optimal design and management (minimum total annual cost, CT) of the water abstraction systems in an integrated manner to include the aquifer along with the pumping station, reservoir and pumping and distribution pipes in a collective irrigation network. This tool has been applied to an on-demand irrigation network located in Spain with 171 ha of drip irrigation in vineyard and olive crops. The optimal reservoir volume is approximately 5000 m3, and the CT for water lift (WL) = 100 m (the most common case for this aquifer) is 325 € ha−1 yr−1. The energy cost is the primary component of CT, both in the abstraction and the water supply to the irrigation network, representing between 57% and 80%. The operation of the pumping station determines the size of the reservoir and the annual costs of the water supply to the network for a given water supply guarantee. The CT increases linearly with the WL, primarily because of the increase in energy costs (Ce), although there is a clear relation between the investment costs (Ca), Ce and the reservoir size, which is only possible to analyse with tools such as DRODIN.


      PubDate: 2016-04-29T03:33:16Z
       
  • Sensor for monitoring rice grain sieve losses in combine harvesters
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Zhenwei Liang, Yaoming Li, Lizhang Xu, Zhan Zhao
      Grain sieve losses are important parameters to judge the performance of cleaning shoes in combine harvesters. To keep grain sieve loss within acceptable limits, an impact-type piezoelectric sensor was developed for real-time monitoring. Rice grain and short straw particle models were established according to their physical properties, and discrete element method (DEM) simulations were carried out to understand their collision behaviour with the sensor. The influence of grain shape, straw length and impact angle on variations of the maximum normal contact force and force rise-time were analysed in detail. Differences in normal collision force, and force rise-time occurred which lead to corresponding differences in signal frequency and voltage amplitude. A signal processing circuit, which mainly consisted of a band-pass filter circuit and a voltage comparator circuit, was designed to discriminate for full grains. Field tests results indicated that measurement errors recorded by the sensor and checked against manually measurements were <4.48%.


      PubDate: 2016-04-29T03:33:16Z
       
  • Framework to develop the mechanisation of date palm cultivation
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Ahmad Mostaan
      The trends in the mechanisation of date palm production were reviewed and five key obstacles were identified: structural heterogeneity, impact of economic and social factors, changing nature of production cycle, lack of innovation in crown access, and the lack of mechanisation indices. A general date palm mechanisation framework was developed which could help understanding and studying the obstacles to mechanisation and derive factors through the principal concepts of revenue loss and availability of the skilled palm-tree climbing workers. Increasing the rate of operation rate with fewer workers would advance date palm production. This trend could be encouraged through lower machinery costs and higher worker safety. Potential advantages of ground-based mechanisation methods are presented through analytical formulation of crown access methods. The ground-based approach appears to be more efficient than conventional approaches using palm climbing or elevating because it simplifies the three-dimensional nature of the working environment into less complex two dimensions. Ground-based methods have limitations due to the increased difficulty of operating in crown zone with increasing palm height. An operational index was defined to help develop the mechanisation of date palm cultivation. The index can reveal the height limits affordability for any date palm mechanisation systems. For each specific mechanisation operation there could be a minimum or maximum height limit and/or a height gap.


      PubDate: 2016-04-25T03:08:28Z
       
  • Orchard worker localisation relative to a vehicle using radio ranging and
           trilateration
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Stavros G. Vougioukas, Long He, Rajkishan Arikapudi
      Safe navigation of labour-aiding robots in commercial orchards will rely on accurate and continuous worker localisation. In this work, an ultra-wideband radio-based system localises a worker via trilateration of four range measurements between antennas on a vehicle and an antenna carried on the worker's belt. Performance results are presented from measurements inside ‘work zones’ around the vehicle, in open space and in an orchard. At walking speed in open space, when body placement allowed full line-of-sight (LOS) between belt and vehicle antennas, position estimate availability was 99.7% and the distance root mean square error (DRMS) was 57.9 cm. Completely blocked LOS resulted in signal outages and unacceptable performance (11.1% availability; 819.7 cm DRMS). In the orchard, full-LOS performance was similar to that in open-space: 99.3% availability and 63.4 cm DRMS error bound. Orchard trees enabled multipath signal propagation, so blocked-LOS performance was far better than in open-space (60.2% availability; 123.6 cm DRMS). Antenna motion effects were studied in open-space and orchard experiments without body interference. Motion introduced non-collocation errors (individual ranges measured at slightly different positions); DRMS error in open space and orchard were 1.6 and 2.2 times larger than respective static errors. In all experiments the 95th percentiles of the errors were almost twice as large as the DRMS errors. Sporadic large errors and signal outages could be addressed by two belt antennas and filtering. The results indicate that radio ranging offers a practicable approach to orchard worker localisation relative to a nearby vehicle operating at slow walking speeds.


      PubDate: 2016-04-25T03:08:28Z
       
  • Drop test of pear fruit: Experimental measurement and finite element
           modelling
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Somaye Yousefi, Habib Farsi, Kamran Kheiralipour
      Pear fruit has a soft tissue that must be protected against mechanical bruises. In this paper, the bruised area of pear fruit was determined by experimental dropping tests and then was predicted by the Finite Element Method (FEM). Three dropping heights (200, 500 and 1000 mm), two impact surfaces (steel and wood) and two fruit orientations (vertical and horizontal) were studied. In order to simulate the fruit in the ANSYS 14 software, volume, density and elasticity modulus of unripe, ripe and overripe fruits were determined experimentally using standard methods. The minimum bruised area was occurred for unripe pear falling on the wood surface at vertical orientation and 200 mm dropping height whereas the maximum value was obtained for overripe pear falling on the steel surface at horizontal orientation and 1000 mm dropping height. The minimum and maximum error for prediction of bruised area by finite element modelling was 0.00 and −60.50%, respectively.


      PubDate: 2016-04-25T03:08:28Z
       
 
 
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