Abstract: Purpose This study was to obtain suitable methods and the combination of market organic waste to make better organic fertilizer.
Method The data were obtained experimentally in the decomposer room. The experimental design was a completely randomized design. The market organic waste consisted of comparing cabbage, banana peduncle, pineapple, added rice straw, and cow manure as bedding. The study used 12 treatments with three replicates. 4 treatments for composting methods (without earthworm) and 8 for vermicomposting (4 treatments using Lumbricus rubellus and 4 treatments using Eudrillus eugeniae). The compost and vermicompost characteristics variables were final weight, reduction, color, texture, and smell. The variables for chemical properties were pH, C-organic, Total Nitrogen, Total Phosphoros, and Total Potassium.
Results Vermicomposting method reduced market organic waste higher than compost 48.67 to 58%. Vermicompost is black like soil and more crumble. C-organic, pH, total Nitrogen, total Phosphorous and total Potassium following quality of SNI 19-7030-2004. The results show the compost with the combination of cabbage and banana peduncle combination (C-T1) had better values on total N (1.95%) and Total K (4.96%). Vermicompost with the combination of banana peduncle and pineapple with Eudrillus eugeniae (E-T3) had better average values on total P (0.43%). The combination of market organic waste used to produce organic fertilizers can be made on a small or larger scale.
Conclusion Vermicomposting is an effective strategy to reduce market organic waste. Composting with T1 combination (C-T1) and vermicomposting T3 combination (E-T3) had better value and was recommended for the following research stage.
Abstract: Purpose Much cattle manure and Tithonia are in abundance in the Guinea savanna of Nigeria where sesame has been found to do well. The cost of inorganic fertilizer is going beyond the reach of the average sesame farmer; the need therefore arises to synthesize farming practices that incorporate the rich organic materials locally available as a substitute for inorganic fertilizer for sustainable food production.Methods A study was conducted at the Teaching and Research Farm, University of Ilorin, Nigeria during the 2018 and 2019 cropping seasons, to evaluate the performance of sesame using T. diversifolia and cattle manures. The following treatments; T. diversifolia (control, 0.9, 1.8 and 2.7 tha-1) and cattle manure (7.5, 15 and 22.5 tha-1) were used. Treatments were laid out in randomized complete block design, and replicated four times. Data on soil water content, growth and morphological characters and yield were collected.Result Results showed that T. diversifolia and cattle manures application improved soil water and nutrient contents, growth and yield attributes of sesame. Tithonia diversifolia applied at 2.7 tha-1 and cattle manure applied at 22.5 tha-1 gave the highest growth attributes, T. diversifolia applied at the rate of 1.8 tha-1 gave a yield of 547.2 kgha-1 and 527.6 kgha-1 in the 1st and 2nd seasons respectively. Cattle manure at 15 tha-1 gave a yield of 517.3 and 517.2 kgha-1 in first and second season respectively.Conclusion Farmers are advised to use T. diversifolia at the rate of 1.8tha-1 for high yield.
Abstract: Purpose Soybean is critical in the global food scenario, and increased grain productivity and sustainability are always sought. This study evaluates the agronomic performance of soybeans with biofertilizer (BF) applications in different soybean phenological stages.
Method Experiments were performed in two regions and designed in randomized blocks using a 2×4 factorial scheme (two cultivars and four BF managements). Representative plants from each parcel were used. Plant biometric variables were assessed on plants at the full bloom stage. At the beginning of grain filling, the leaf and seed biochemical components were measured. Quantitative yield components were measured at harvest.
Results In both areas, the BF did not affect the soybean leaf area index, leaf dry biomass, and branch dry biomass. The BF application improved the total sugars, starch, and reducing sugars in area 1. In area 2, the chlorophyll was similar among the BF managements. Soybean cultivars and BF did not affect seed protein content in area 1. In area 2, the BF application presented a similar or greater soybean yield compared to control (no BF). The divergences observed between areas may be related to interactions between the soil-climatic conditions and the soybean cultivars.
Conclusion Choosing a more appropriate soybean cultivar is fundamental to obtaining higher yields. Nutritional management with leaf-applied BF is an alternative to increase soybean field performance. However, it is still necessary to consider the interactions of the BF with the crop genetics chosen for the region of cultivation and the best dose and time of application.
Abstract: Purpose This paper investigates the composting recovery of different bio-wastes and the use of the composts produced as soil fertilizer and organic amendment.Method A composting process was carried out for 111 days using different organic wastes (fruits, vegetables, olive pomace, poultry, and cattle manure). The physicochemical properties of the generated compost were determined. The quality of the compost produced was evaluated by measuring pH, carbon/nitrogen (C/N), dry matter, and organic matter. A phytotoxicity test (germination test) was conducted to complete the analysis.Results The results of the physicochemical properties complied with AFNOR standards. The pH ranged between 7.3 and 8.7. The C/N ratio was between 10.05 and 18.46, and organic matter content varied between 33.6 and 72.7%. The phytotoxicity test showed that the safety of compost as a soil amendment is related to the applied dose and the type of crop.Conclusion The physicochemical parameters and phytotoxicity test showed that the compost obtained can be used as organic fertilizer due to its organic matter content and mineral elements.
Abstract: Purpose Our study concerned the recovery and reuse of sludge from aquaculture system implemented in Ain Defla District situated in the North-West of Algeria. As a biotreatment and ecological stabilization technique, vermicomposting of aquacultural sludge with Eisenia fetida earthworms has been advocated. The main goals were to assessthe impact of vermicomposting on the quality of aquacultural sludge in terms of stabilization and hygienization, and to investigate its potential use in agriculture as a biofertilizer without compromising the quality of agricultural products.
Method The vermicompost was used to amend the soil and assess its impact on some growth parameters of Phaseolus vulgaris.L snap bean was considered. The physical and chemical parameters of sludge were also evaluated.
Results Significant increase of earthworms’weight and length by more than 27 and 22%, respectively, after 21 days of sludge vermicomposting was obtained. Also, significant differences were noted for selected plants’ agronomic parameters in soils amended with aquacultural sludge, compared to the control (unamended soil). In fact, beans with vermicomposted sludge had substantial increases in plant height, leaves weight, and chlorophyll (a) level of 29 cm, 3.6 g, and 0.8 g/g, respectively, compared to 20 cm, 1.5 g, and 0.46 g/g in control.The results also showed that the vermicomposting process allowed for decreased faecal coliforms and streptococcus in the aquacultural sludge.
Conclusion The end-product was a safe biofertilizer for use in agriculture.
Abstract: Purpose The reuse of treatedt wastewater (TWW) in agriculture may affect the growth of plants. The goal of this study is to investigate the potential use of TWW in irrigating Lily in presence of Arbuscular Mycorrhizal Fungi (AMF) in a closed soilless system.
Method In the first experiment, plants were irrigated with a mixture of 3 part nutrient solution: 1 part treated wastewater (3NS:1TWW) supplemented with 50, 125, 160 or 200 mg L-1 Ca to determine the optimal Ca concentration supplement that would give the highest plant growth. In the second experiment, the plants were irrigated with a nutrient solution or a mixture of 3 part nutrient solution: 1part treated wastewater (3NS:1TWW) supplemented with 160 mg L-1 Ca in the presence or absence of AMF.
Results The results indicated that the plants receiving the higher concentrations of Ca (160 or 200 mg L-1) showed better growth performance. The results showed that the plants receiving (3NS:1TWW) had a significantly higher dry weight of adventitious roots and fresh weight of the flower bud than those receiving nutrient solution. The flower bud was longer in presence of AMF. The highest shoot fresh weight was recorded for non-AMF plants receiving 3NS:1TWW, and the least shoot fresh weight.
Conclusion The most efficient solution is to supplement the 3NS:1TWW irrigation solution with 160 mg Ca L-1 to reduce the salinity effects of TWW. Moreover, it is recommended to inoculate the roots of the Asiatic lily plants with AMF to achieve the longest flower.
Abstract: Purpose To investigate the effects of the usage of different animal additives on physicochemical characteristics in the process of food waste composting and quality ofthe final product.
Method Five binary combinations of FW with 40% of each animal additive (llama, horse, sheep, cow and chicken manure) were used, plus a control treatment (without any additive). Physicochemical (such as temperature, pH, electrical conductivity, loss of organic matter, C/N ratio) and microbiological parameters were determined for each treatment; same as heavy metals content (As, Cd, Cu, Cr, Hg, Ni, Pb and Zn) and phytotoxicity by calculating the germination index. The composting process lasted 50 days.
Results We observed the three typical phases related to temperature changes of composting process (mesophilic, thermophilic and cooling) in treatments with additives. The application of llama, horse, cow and sheep manure in food waste composting favors evolution of physicochemical parameters towards optimal values, improving the process and increasing the quality of products obtained. The values of physicochemical and microbiological parameters, heavy metals and germination index of compost obtained from addition of llama dung were within the permissible limit for Class A compost, without restrictions of use, in accordance with current Argentine Regulations. The other products qualified as Class B, with potential use as fertilizer but presenting some risk for the environment.
Conclusion According to our findings, llama dung was the additive that contributed to produce a more efficient food waste composting process, generating the highest quality compost.
Abstract: Purpose Takakura Composting Method (TCM) is a simple and cost-effective aerobic composting method using locally available materials and has been widely introduced in Indonesia and other countries. This study tracked the progress of scaling the TCM up to 1 tonne/day of organic waste input at the decentralised composting centre in Bandung City, Indonesia. A comparative study was conducted to assess the environmental and economic impacts by using the performance data of TCM.
Method A combination of Life Cycle Assessment and Cost-Benefit Analysis were performed to compare the net greenhouse gas (GHG) emissions and Net Present Value (NPV) of six different municipal solid waste treatment scenarios to treat 1 tonne of food waste. The impacts were also assessed between different system boundaries with or without compost use, and by applying different emission factors for composting to the static windrow and TCM.
Results Home composting showed the least GHG emissions (-601 kg CO2-eq/t) and highest NPV (Indonesian Rupiahs (IDR) 518,790/tonne) and is thus suggested to be the most favourable option. While the least favourable options were either landfilling which showed the highest GHG emissions (628 kg CO2-eq/t), or incineration which showed the lowest NPV (IDR -818,373/tonne).
Conclusion As the home composting was not considered to be a realistic option for wide application, a combination of one large centralised composting centre and a small decentralised composting centre in each sub-district is suggested in the case of Bandung City.
Abstract: Purpose The current use of pesticides and chemical fertilizers harms the environment, alternative substitutions using organic materials are needed. One of them is utilizing the dairy industry sludge waste to become a Super Liquid Fertilizer (SLF). This study aimed to analyze the nutrient quality of SLF (a dairy industry sludge waste that was added to some the microbial activators).
Method The types of microbes and the number of nutrients in pure sludge were identified, followed by composed SLF and applied to the larvae of Spodoptera litura to see the pathogenicity. Data were analyzed using SPSS.26 software.
Results The types of microbes that exist in the pure sludge waste of the dairy industry are dominated by Pseudomonas bacteria, as much as 50%. The nutrient content of SLF is appropriate to Indonesia’s national standard for liquid organic fertilizer. Analysis of varian (ANOVA) analysis shows that the addition of activator microbe at P3 is the best. The number of microbes in SLF is significantly different (P < 0.05) at each treatment, where P3 is the best treatment. The pathogenicity of SLF is also good, as evidenced by the motility of the Spodoptera litura reaching 98% in the P5 treatment for 96 hours.
Conclusion This research has succeeded in producing SLF with the nutritional value of nutrients that are close to the Indonesian Ministry of Agriculture. The number of bacterial colonies in SLF is more than 106 CFU/mL, especially in the P3 treatment. SLF can kill Spodoptera litura caterpillars in a time period of 46 hours.
Abstract: Purpose Agricultural wastes are by-product of agricultural processing. These wastes could serve as alternative materials for soil amendment and nutrient sources for crop production. A screen house experiment was conducted for two successive seasons (2019 and 2020) to evaluate the performance of charred poultry feather waste and plantain peel as nutrient sources on the growth, yield and nutrient uptake of two varieties (Eva and Nemo-netta) of tomato.
Method Four levels each of charred poultry feather waste and plantain peel at 2, 5, 8, and 10 t PF ha-1, control and 200 kg NPK ha-1 were used as treatments. The bags were arranged in a completely randomized design. Treatments were replicated four times.
Results The application of charred poultry feather waste and plantain peel significantly increased vegetative growth and yield parameters of tomato when compared with the control. Results also showed that combined application of the amendments compete favourably with the application of inorganic fertilizer. Higher values for all the parameters were observed when 5 t PP ha-1 + 5 t PF ha-1 was applied though similar values were found on the vegetative parameters with the applications of 2 t PP ha-1 + 8 t PF ha-1, 10 t PP ha-1, and 10 t PF ha-1. Yield and micronutrient concentration of Eva was also found to be higher than that of Nemo-netta.
Conclusion The effects of 5 t PP ha-1 + 5 t PF ha-1 showed clear increase in vegetative, yield and nutrient uptake of Eva variety as compared to Nemo-netta.
Abstract: Purpose Because of the steep shortage in freshwater supply in the Israeli-occupied West Bank, raw wastewater (RWW) has been widely used to irrigate vegetable crops. This study aims to detect the effects of irrigation with raw wastewater on crops cultivated in Wadi Al-Far’a, Palestine.
Method A total of 300 soil, crop, and RWW samples were randomly collected from Wadi al-Far'a, an area with a long history of irrigating crops with raw wastewater. A survey questionnaire was also used to collect data on the parasites-infected farmer.
Results Results showed that percentages of contaminated vegetables, soil, and RWW samples were 10.2%, 27.0%, and 47.5%, respectively. Crops leave indicate contamination with parasite eggs depending on their contact with surface soil, e.g., contamination of zucchini (leaves rest on surface soil) and mallow (upright plant stand) was 19.0% and 2.0%, respectively. The highest and lowest soil contamination with parasites eggs pertained to A. lumbricoides (30.0%) and T. trichiurid (19.2%).
Conclusion Certain mitigation measures should be used to limit the danger of farmers becoming infected with common parasites, particularly Ascaris lumbricoides. Farmers' awareness of the manner of parasite transmission and adherence to safety regulations should be among them.
Abstract: Purpose The main aim of this study was to treat olive mill wastewater (OMW) using a photo-Fenton's solar reactor; to investigate its potential use as liquid fertilizer and to evaluate its impact on pepper crop.
Method Olive mill wastewater was collected in a tank 1000 L and supplemented with 2000 gr FeSO4.7H2o. After that, 150 ml H2O2 was added to the tank to start Fenton's reactor. The treated OMWwas collected in a container and NaOH with a concentration of 1 M was added to improve the pH of the treated OMW. Pepper seedlings were cultivated on 16 February, 2020 inside the greenhouse for a period of five months. The treated OMW was used as liquid fertilizer and compared with chemical fertilizer as control.
Results The pH and electrical conductivity of treated OMW were 7.5 and 7.6 dS/m, respectively. Furthermore, the control produced the highest yield and fruit number significantly (p < 0.05) compared to the other treatments, followed by OMW treated by stabilization bond (SB-OMW100%). Also the treatments fertilized by OMW treated by solar reactor (SR-OMW50%) and stabilization bond (SB-OMW100%) produced the same plant length at the end of the growing period.
Conclusion The concentrations of N, P, and K of treated OMW (0.21, 0.06, and 0.68 respectively) were quite low and supplementary fertilization was necessary to improve the nutrients value of the treated OMW. The solar reactor could be a valuable and useful tool in treatment of olive mill wastewater for agricultural purposes mainly on small scale sites.
Abstract: Purpose This study aimed to evaluate the biochemical characterization of solid state fermented maize (Zea mays) cob and its use in poultry feed production.
Method Solid state fermentation was carried out at room temperature for 72 hours using Rhizopus oligosporus inoculum with a well prepared phosphate buffer (50 mM , pH 6).
Results Results showed a significant (p< 0.05) increase in glucose and decrease in sugars and soluble proteins concentration in the R. oligosporus fermented maize cob. At 10% inoculum, the highest concentrations of glucose, reduced sugars and soluble proteins were 1.15±0.21, 45.7±0.6 and 12.9±0.3 mg g-1, respectively. Similarly, the total phenol, flavonoid content and antioxidant activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and amylase activity of maize cob increased significantly (p < 0.05) with fermentation. Broiler chickens fed with fermented maize cob of 10% inoculum had the same weight gain as the control (1.4±0.1kg). Fermentation did not induce a significant difference (p<0.05) in the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP).
Conclusion The observed increase in proteins and sugars in the fermented products suggests their suitability as excellent components for animal feed production. Thus, the livestock feed formulation industries might benefit from the usage of fermented maize cob as a raw material in animal feeds as well as a protein fortifier.
Abstract: Purpose Rice biomass waste can be used as a soil amendment. This study examined the effect of the application of rice husk biochar and straw compost on several soil properties and yields of rice and soybeans in tropical upland.
Method Field experiments were carried out with two applications of rice husk biochar and straw compost on upland rice and soybean cultivation, respectively. Three-levels of rice husk biochar application (5, 10, and 20 t ha-1) and straw compost (5 t ha-1) along with the control. The changes in soil chemical properties like pH, C, N, CEC, P, K, Mg, Ca, Na, and physical properties including soil bulk density, particle density, total porosity, macropores, micropores, permeability, and soil water content at various pressures were measured. The grain yields of rice and soybean were also recorded.
Results Total-C and exchangeable-K increased after the second application of rice husk biochar and straw compost. There was a significant improvement in total porosity and micro-pores, soil water content especially at PF 2.54 (0.33 Pa) and PF 4.2 (15 Pa), and increased soybean yield compared to control. Based on the overall results, we got a significant effect of rice husk biochar at higher doses (10 and 20 t ha-1).
Conclusion The application of rice husk biochar (at doses 10 or 20 t ha-1) and straw compost 5 t ha-1 gave a positive effect on several soil properties including total-C, soil porosity, and soil water content, especially at pF 2.54 and pF 4.2, and also increased soybean yields.
Abstract: Purpose To evaluate the production and the quality of seedlings of different pepper genotypes produced on millicompost as an organic substrate.
Method Three experiments were carried out, one for each pepper genotype (ENAS-5007, ENAS-5031 and ENAS-5032) in which three substrates were evaluated: 100% Millicompost (S1); Millicompost MIX (50% millicompost + 50% powdered coconut fiber) (S2) and Carolina organic® commercial substrate (S3). Variables evaluated: shoot and root dry mass (SDM and RDM), number of leaves (NL), plant height (PH), seedling vigor (SV) and clod stability (CS). The data were subjected to the analysis of variance and the means were compared by the Tukey’s test at 5% probability level.
Results For the ENAS-5007 and ENAS-5032 genotypes, there was a significant difference in all the variables analyzed, being S1 and S3 the substrates with the highest and the lowest performances, respectively. In the ENAS-5031 genotype, SDM and RDM did not differ between S1 and S2. For ENAS-5031, there were significant differences in PH, NL and SV, in which S1 promoted the best results; however, no significant difference was observed for CS.
Conclusion The 100% millicompost substrate promoted the best development of pepper seedlings in all the three genotypes evaluated. However, the combination of the millicompost MIX has the potential to be used, as it promotes seedlings of superior quality in comparison to the commercial substrate, maximizing the use of millicompost as a substrate for the production of organic pepper seedlings.
Abstract: Purpose Raw and composted oil-cakes of neem, madhuca and simarouba were evaluated for their effect on plant growth, yield, and management of Alternaria tenuissima leaf spot disease, and rhizosphere microorganisms in chilli crop.
Method The oil-cakes were composted in simple pits containing a mixture (6:1:1) of individual oil-cake, soil and rice straw. Growth promotion and disease incidence were assessed in plants grown in soil amended with raw or composted oil-cakes of neem, madhuca and simarouba in pot and field. Rhizosphere microflora was also determined in all treatments.
Result Raw oil-cakes and their composts increased plant growth and yield and considerably decreased disease incidence and severity of A. tenuissima leaf spot in chilli grown in pot and field. The composted oil-cakes of simarouba were most effective in improving plant growth and yield and decreasing leaf spot disease in chilli, followed by madhuca and neem oil-cake compost. Fruit yield and vitamin C content were also high in simarouba compost. All composted oil-cakes increased beneficial microbial population in the rhizosphere, including phosphate solubilizers, free-living N2 fixers and Trichoderma species. The compost amendment decreased A. tenuissima population in the soil at the same time.
Conclusion The growth promotion, yield increase and disease reduction in chilli were attributed to chemical compounds in oil-cakes and stimulation of beneficial microbes in the rhizosphere by raw or composted oil-cakes. This study demonstrated that composted non-edible oil-cakes could be used for soil amendment in place of agrochemicals to increase productivity, manage soil-borne diseases and improve soil health.
Abstract: Purpose The objective of this study was to evaluate soybean production and nutrient availability in the soil using doses of organic fertilizer formed from chicken carcasses, compared to the use of mineral fertilizer.Method The evaluated treatments, produced from chicken carcasses, were calculated to provide 0, 30, 60, 90, 120 kg ha-1 of P2O5, that is, 0; 3.37; 6.71; 10.11 and 13.48 t ha-1, respectively. We also evaluated an additional treatment, in which 60 kg ha-1 of P2O5 were applied, through 400 kg ha-1 of NPK 10-15-15; this was carried out in a rural area located in the municipality of Ubiratã, Western Paraná. After harvest, the plant production components of soybean were evaluated, as well as the P content in the soil. The data were submitted to analysis of variance (ANOVA). The effect of the organic compost doses was evaluated by regression analysis and the additional treatment was compared by contrast analysis.Results The use of organic compost doses based on chicken carcass in soybean cultivation resulted in linear increase in plant height, number of pods per plant, thousand grain weight productivity and oil content in the grains. It was also efficient in increasing P levels of the soil. Compared to mineral fertilizer, the use of organic compost resulted in greater amount of P available in the soil but had a lower productivity.Conclusion Organic fertilizer from chicken carcass was able to increase the production components of soybean as well as to increase the soil P availability.
Abstract: Purpose Agronomic and environmental reasons force farmers to know the total P concentration of composted cattle manure. Laser-Induced Breakdown Spectroscopy seems proper to obtain such information. For logistic reasons (carriage, storage, field application, etc.), a dry matter characterization is also needed.Method Thirty samples of feedlot compost at different stages of stability and maturity were studied. Samples were dried at 50°C for dry matter characterization. As a reference method to determine total P concentration, wet digestion and colorimetry were employed. The area of the P I line emission obtained by laser-induced ablation of the samples was measured to estimate the total P concentration. Randomized calibrations through a modified version of the Kennard-Stone algorithm based on the Mahalanobis distance were performed.Results Dry matter varied from 40% to 90%, and no pattern was found related to compost origin, maturity, or stability. The total P concentration of the studied compost ranged from 1800 ppm up to 11200 ppm. Almost 80% of the calibration fittings have an R2 ≥ 0.895. The mean validation error was less than 22% for about 80% of the calibrations, with a mean prediction error bound to 40%. Discarding outliers, the errors were reduced to 19% and 30%, respectively.Conclusion Water content must be considered in addition to other characterizations due to logistic implications. Calibrations with a 30 percent of prediction error were achieved, which seems enough as a first approximation to predict the total P content in compost for utilization in farms to recycle nutrients.
Abstract: Purpose Fertigation plays an important role in the so-called circular economy since it relies on the reuse of water and nutrients; therefore, this method is fundamental for production in areas with scarce resources. This study aimed to evaluate the effects of fertigation of soil plots with sewage on soil attributes, germination of seeds, and growth of bean and corn.
Method Due to the low concentrations of macronutrients in the sewage, the applied dose was calculated based on the water deficit. Three plots cultivated with maize and three plots cultivated with beans were fertigated, while the same number of plots received irrigation and mineral fertilization in amounts equivalent to the dose of nitrogen administered in the sewage for comparison.
Results There was an increase in the cation exchange capacity (74.6%), nitrogen (10.4%), available phosphorus (190.5%), and organic matter (44.9%) contents in the fertigated soil compared to those in the soil of the plots that received chemical fertilization, resulting in greater germination and corn and bean growth. Analyses indicated that the coliform count in beans is below the detection limit of the technique used.
Conclusion Based on the results obtained, there are indications that fertigation can provide improvements in soil attributes at values higher than those provided by chemical fertilization, reducing the need to apply these macronutrients and irrigation water to the soil. Furthermore, fertigation can be sanitary and safe, since the count of microorganisms in the beans was not higher than that recommended by the World Health Organization (WHO).
Abstract: Purpose Nematode diseases are major constraints in tomato production. Screenhouse and field experiments were conducted to assess the efficacy of Effective Microorganisms-Fermented Plant Extract (EM-FPE) and compost manure singly and in combination on Meloidogyne incognita infecting tomatoes.
Method Screenhouse and field experiments were designed respectively as 2×5 and 2×4 factorial fitted into a completely randomized design (CRD) in the screenhouse and randomized complete block design (RCBD) on the field. For single treatments, 100 ml of EM-FPE or 200 g of compost was used per plant while 50 ml of EM-FPE and 100 g of compost were combined and used per plant for treatment combination. Pots that did not receive any treatment served as control. Data were collected on growth parameters, fruit production, galling, and soil nematode population. The data collected was subjected to analysis of variance (ANOVA) where significant differences in means were separated using Fisher’s Least Significance Difference (LSD) Test at P = 0.05.
Results In both trials, treated plants performed significantly better. No significant difference was recorded among the three treatments for soil nematode population and root galling on the field. But in the screenhouse trial, plants treated with the combination of EM-FPE and compost recorded higher soil nematode population (150) and root galling (7) at harvest but the plants performed well. Among the treatments, compost manure applied singly gave the best result with respect to vegetative growth, flower formation, and yield of the tomatoes.
Conclusion This study reveals that both treatments, EM-FPE, and compost manure could be relied on for effective control of Meloidogyne incognita in tomatoes.
Abstract: Purpose This study evaluated the response of hot pepper (Capsicum annuum var. Red chili) towards cow vermicompost application under field conditions.
Method Cow vermicompost was supplied in four levels (0, 5, 10, and 15 t ha-1) across the two growing seasons in 2017 and 2018.
Results Vermicompost application significantly increased the plant height, internode distance, and the number of lateral branches in both seasons. It was noticed that manuring with 15 t ha-1 of cow vermicompost resulted with enhanced chlorophyll contents, fruit yield, and fruit number in both years. In both seasons, the highest leaf number, fruit weight, and total soluble solids are related to the third treatment (10 t ha-1 of cow vermicompost). The results showed that 1000-seed weight and vitamin C content were affected by cow vermicompost. Data showed that manuring with vermicompost (5 t ha-1) caused the best quality components in 2017 and 2018.
Conclusion It was concluded that the application of vermicompost had a significant impact on vegetative and reproductive growth and fruit quality of hot pepper.
Abstract: Purpose This study investigated the potentials of crop residues to improve the growth and yield of plantain as well as its proximate compositions.
Method Biochar, Cocoa pod husk and Rice bran were applied at the rates 4, 6, 8, and 10 tons/hectare after three weeks of sucker establishment on experimental plots. The experiments were carried out in two different locations; FUTA and Ejigbo, and were laid out in a completely randomized block design with four replications. The following growth parameters including leaf number, plant height, stem girth, leaf area, and sucker number were monitored for six consecutive months commencing from 90 days after sucker establishment while the yield parameters including bunch weight, finger number, finger girth, bunch length, and yield per hectare were determined during harvesting. These parameters were determined for both parents and ratoon. Also, the proximate composition of the plantain was determined.
Results There was no statistically significant difference for all the growth parameters determined in both FUTA and Ejigbo locations for both the parent and ratoon crops except the leaf area which increased significantly in amended soils compared to the control. All amendments produced higher bunch weight, finger number, and yield per hectare compared to the control. The different soil amendments did not alter the proximate compositions of the plantain significantly for the two locations.
Conclusion It is therefore concluded that crop residues especially cocoa pod husk at the rate of 10 tons/hectare be used as alternative to mineral fertilizers to enhance soil health and productivity.
Abstract: Purpose This study aimed to produce a value-added product by co-composting sawdust with food waste using a small-scale composter.
Method The composting experiment was carried out using 60L composting bins with a hole of 3 mm and 10 cm apart drilled on its side. Three experimental trials 1, 2 and 3 were adopted in this study with mixture of sawdust and food waste (Trial 1= 80% sawdust + 20% food waste, Trial 2 = 70% sawdust + 30% food waste, Trial 3 = 60% sawdust + 40% food waste). The composting process lasted for 90 days. Parameters examined throughout the composting process include temperature, moisture content, pH, electrical conductivity, organic matter content, and organic matter losses.
Results The results indicated that all the compost trials exhibit good development of composting process, with the highest solid organic degradation reached in a shorter period in compost trial 3. The temperature profile of the three trials are the same and above 60 0C after 30 days of composting. The compost samples had a pH ranging from 5.9 to 9.4. The electrical conductivity of the three composting trials was following the recommended value. The best compost trial that produces quality compost is compost trial 3.
Conclusion The results showed that all composts obtained were stable and matured. In brief, recycling sawdust through the composting process to obtain valuable end products is adequate but in the presence of nitrogen-rich waste, such as waste food materials.
Abstract: Purpose Chicken eggshell as a byproduct of the egg product industry makes serious problems to the environment. The aim of this study was to evaluate the effect of eggshell as a potential option in supplementing of the organic matter and improvement of soil conditions in the pot culture and the area.
Method Two pot experiments were carried out to estimate the effects of CD and CDES vermicomposts provided from cow dung and cow dung + eggshell’s powder, respectively, on symbiotic relationships of Serendipita indica with wheat and soil enzyme activities tested under sterilized and non-sterilized soil conditions, respectively. Two in vitro experiments were also conducted to test the effects of eggshell extract and humic and fulvic acids extracted from CD vermicompost on S. indica growth.
Results CDES vermicompost improved soil enzyme activities of urease, phosphatase and invertase. Root colonization of wheat with multiple species of mycorrhiza and facultative symbiont S. indica was improved by CDES. S. indica growth was induced by eggshell extract. Humic and fulvic acids increased in S. indica mycelia mats dry yield. Results revealed when cow dung was amended with eggshell powder provided a better condition for earthworm growth and enhancing the colonization percentage of wheat root with indigenous mycorrhizal fungi. CDES vermicompost caused the increase in soil basal respiration and soil enzymatic activities.
Conclusion Eggshell powder growth promoting effect can be attributed to the biologically active compound that exists in eggshell extract.
Abstract: Purpose The decreasing number of peatlands has driven the search for new cultivation substrates. The aim of this study was to evaluate the use of different composts as growing media in the production of vegetable seedlings (pepper and tomato).
Method Composts were produced from: discarded carrots (ZC), fats (FC), and biosolids (BC) from the dairy industry. They were used as peat substitutes in different doses depending on the germinating species: control (CS-commercial substrate) and three growing media prepared with perlite: 25, 35, and 45% of ZC, FC, and BC for pepper seedlings and 40, 55 and 70% of ZC, FC, and BC for tomato seedlings. When the plants were ready for transplantation they were harvested and the data were collected to assess the development of the seedlings in the different growth media.
Results The obtained results suggest the possibility of total substitution of the CS by ZC, FC, and BC to produce pepper and tomato plants in commercial nurseries. The plants cultivated with composts presented higher concentrations of total dry matter compared to the controls. Photosynthetic pigments were affected by the presence of FC and BC, whereas TSP concentration was favored by BC.
Conclusion Ours results suggest that it is feasible to perform a total substitution of commercial substrates with composts of different origins and compositions for the production of pepper and tomato plants in commercial nurseries.
Abstract: Purpose This field study evaluated the interactive effects of biochar (BC) and sewage sludge (SS) on P bioavailability and spinach yields for two seasons.
Method Treatments were combinations of biochar (0, 2.5 and 5 Mg ha-1) and sewage sludge (0, 6 and 12 Mg ha-1), or mineral fertilizer (200, 28, and 18.9 kg ha-1), amended in a randomized complete block design to Luvisol and Cambisol.
Results Significant (p < 0.05) yield increase of 53 and 65%, respectively occurred with increasing sole biochar doses on the Luvisol. Both applied alone and in combination with BC, the high rate of SS increased (p < 0.05) yields on the Luvisol over two seasons. Complimentary effects of 6SS+5BC on the Luvisol showed the highest yield increase for the study period. Co-application of amendments on the Cambisol decreased (p > 0.05) yields compared to sole amendments. Mehlich – 3 extractable P (M3-P) in control plots (CONT) increased between seasons, presumably due to P inputs from the irrigation water. Co-amendments on the Cambisol resulted in higher M3-P increase over mineral fertilizer than on the Luvisol in both seasons. Accumulation of M3-P in control plots confounded correlations between crop yields and available P. Higher P under BC compared to SS amended soils emphasize biochar capacity to capture P from irrigation water.
Conclusion The results suggest that combined low rates of SS and BC can have significant effects on P availability and crop yields. Biochar enhanced plant P uptake, but decrease in yields with simultaneous increase in M3-P between seasons warrants further research.
Abstract: Purpose Chicken eggshell (ES) is a global biowaste product of poultry industry and an enriched source of calcium required for plant growth. Therefore, the present study has been carried out to assess the potentiality of the combination of ES with vermicompost (VC) and chicken feather protein hydrolysate (CFPH) on growth and yield improvement of Capsicum plants.Method A field study was conducted through randomized block design (RBD) with eight treatments having three replicates for each. Principle Component Analysis (PCA) have performed to analyze the yield related parameters of plant. Nutritional components of VC and ES were also analyzed.Results The PCA analysis of the field experiment data has indicated that the combination of ES, CFPH and VC (in a ratio of 100:10:3) remarkably increased the agronomic parameters of capsicum plant about four folds as compared to its chemical counterpart and control, while together VC and ES strongly influences the characteristics of fruits. The first two dimensions of first and second PCA analysis showed 88.39 and 66.91 percent of the overall dataset inertia respectively, explaining 88.39 and 66.91 percent of the total variability. These two values are higher than their respective reference values of 36.32 and 46.76 percent indicating substantial variability.Conclusion The co-application of ES, CFPH with VC could enhance the yield parameters of crops by enriching the soil with both micro and macronutrients. It also serves as a source of organic compost with concomitant reduction in the use of chemical fertilizers.
Abstract: Purpose Increase in global population and food demands have necessitated the need to enhance the health status of agricultural soils to overcome retrogresses in crop yields. Thus, amply use of animal manures is critical to improving low fertility status that characterised most agricultural soils in the tropics.
Method This study investigated the effects of various animal manure types on soil properties and performance of okra (Abelmoschus esculentus L) grown on a degraded coarse-textured ultisol. The treatments were: T1, poultry manure; T2, cow manure; T3, pig manure applied at 702 g pot-1 (equivalent to 30 t ha-1) to a 10 kg potted soil and T4, control unamended soil.
Results Amended treatments had 0.73-10.9% increase in organic matter, 191-370% increase in soil N, 30.4-170% and 25.5-76.5% increase in soil P and K, respectively relative to the control treatment. Amended treatments recorded significantly higher (p <0.05) plant height, stem girth, okra biomass and yields compared with the control treatment. Poultry manure showed superiority over cow manure and pig manure for pH, soil nutrients, okra yield, okra growth and yield parameters measured.
Conclusion The results indicate that animal manure application increased okra yield and enhanced the fertility status of a degraded coarse-textured ultisol. Thus, application of animal manures can help overcome low fertility challenges associated with degraded tropical soils.
Abstract: Purpose Scarcity of effective manures frustrates the adoption of organic-based soil fertility management in tropical agriculture. Cattle dung (CD) is hugely generated but underutilized due to its high carbon-nitrogen ratio and low mineralization rate compared with poultry droppings (PD).
Method Effects of CD utilization options on fertility of sandy-loam Ultisols and maize growth were assessed under glasshouse conditions. Four options, CD in its cured form (CD), CD-derived biochar (BC), CD water-soaked fermentation (FM) and CD+urea (CDU), were assessed against cured PD and NPK-15:15:15 as reference manure and fertilizer, respectively. Organic amendments were added to 5-kg potted soils at 10-t-ha–1 equivalent before sowing except FM added alongside CDU’s urea at 250 kg ha–1 and NPK-15:15:15 at 400 kg ha–1 after sowing.
Results After 9 weeks, BC, CDU and PD had similar effects on soil pH, organic matter, total N and available P which increased by 49-51%, 30-34%, 200-333% and 164-176%, respectively relative to the control. The BC always showed maize plants similar to the tallest ones in PD. Maize dry matter was the highest in CDU/PD (35.06-35.56 g pot–1) and the lowest in control (9.56 g pot–1). Residual effects showed that BC and PD maintained the increases in soil pH, while CDU/PD always showed tallest plants and enhanced dry matter over the rest except BC. Soil pH, Mg2+ and base saturation together caused 93% of treatments’ effects on dry matter.
Conclusion Converting CD to BC or supplementing it with urea (CDU) in coarse-textured tropical soils could have prolonged liming and/or biomass productivity-enhancing effects as PD.
Abstract: Purpose Phosphorus (P) is one of the key elements in the agricultural sector, allowing improved production yields. Phosphate rock is a natural source of phosphorus; however, its low reactivity limits the release of P available to plants in the short term, conditioning its application in a direct way. Research was conducted to determine the effect of phosphate rock on a manure compost mix by measuring its availability of P and its microorganism activity.
Method Cattle manure, equine manure, and poultry manure from three provinces of the department of Boyacá, Colombia, were moistened up to 60% with fermented mineralized liquid and composted with different proportions of phosphate rock. After 60 days of composting, the mineral content and microorganism activity were measured.
Results This study revealed three notable results. First, the addition of phosphate rock led to an increase in total and available P and a decrease in water-soluble phosphorus and inhibitory effects of phosphatase activity. Second, composting with the three manures resulted in microorganism activity levels higher than 700*104 CFU, exceeding the NTC’s definition of an inoculant fertilizer in the agricultural process. Third, a strong positive relationship was found between ammonia-oxidizing bacteria and PBII, a medium correlation was found between PSM and TP, and a negative correlation was found between pH and PT.
Conclusion Composting manure with phosphoric rock could be a low-cost source of macronutrients, minerals, and microorganisms to promote soil health and crop yields.
Abstract: Purpose Oyster mushroom (Pleurotus ostreatus) is becoming more popular as an efficient biotechnological procedure for upcycling agricultural by-products into valuable human food. This study looked into the possibility of employing banana residue (BR) and sorghum stalks (SS) as localized feasible rice straw (RS) substitutes for cultivating P. ostreatus. This has the potential to improve the livelihoods of rural agricultural communities in Egypt, as well as those in other parts of the world.
Method For two successive trials, three sole substrates (BR, SS, and RS) and six various combinations of SS and BR each with rice straw at 1:1, 1:2, and 2:1 ratio were tested. Agronomic features, antioxidant capacity, and crude protein contents of mushroom basidiocarps were measured. The chemical profile of the three raw and spent sole substrates was also studied.
Results The sole BR substrate was superior to both RS and SS in terms of basidiocarps yield and both exterior (average cap weight, diameter, and thickness) and interior (crude protein and total antioxidant activity, phenols and flavonoids contents) quality attributes. The yield of basidiocarps developed on the sole SS substrate was far lower than that of the other substrates. It is worth mentioning that, BR tended to contain high initial potassium, phosphorus, cellulose, and total carbohydrates concentration.
Conclusion Sole BR could entirely substitute sole RS as a substrate for the production of Pleurotus ostreatus.
Abstract: Purpose The leather industry produces huge quantities of proteinous solid wastes and is being dumped or improperly utilized resulting in economical losses or causing an environmental problem. An efficient, low-cost procedure was developed to convert animal fleshings into plant growth promoters (PGP).
Method The fleshings were hydrolyzed and analyzed for moisture, fat, ash, and nitrogen contents. The protein hydrolysate is incorporated with phosphorous and potassium in a suitable method to convert into plant growth promoters. The obtained product is characterized and field application studies have been conducted with ladyfinger plants (Abelmoschus esculentus).
Results The detailed characterization of PGPs through physicochemical analyses gave a deeper understanding of microstructures. Spectroscopic features and FT-IR studies confirmed the potential of PGP. The bio-metric results have shown that the application of plant growth promoter yielded better results and chemical characteristics.
Conclusion Hence this study provided a viable solution for the conversion of proteinous solid wastes into plant growth promoters.
Abstract: Purpose The study assessed the quality of compost produced by the Black Soldier Fly Larvae (BSFL) in terms of the compost nutrient level, microbial activities, and the bioaccumulation of possible heavy metals in the organic solid waste.Method The study used the pre-experimental study design, one-group pretest-posttest to obtain the data. Five experimental units were used for the study, which include the daily feeding rate for the five different groups of larvae. The experiments were replicated three times. The nutrient level, heavy metal content and presence of microbes were analyzed before and after the decomposition process.Results The study discovered that the Nitrogen, Phosphorus and Potassium (NPK)content increased in the compost produced. Cross-contamination of Total Coliform from feed to the prepupae were significant while regrowth of Total Coliform in compost were insignificant. After the composting process most heavy metals like Fe had insignificantly increased in the compost .Conclusion It can be concluded that larval composting enhance the regrowth of pathogens since the process is entirely mesophilic. Bioaccumulation of most heavy metals was minimum, increasing the level of these heavy metals in the compost. The nutrients were extremely high in the compost to the extent that can cause phyto-toxicity. Post-treatment of the compost is needed to make BSFL compost viable for the market.
Abstract: Purpose Due to the urgent need for sustainable agro-industrial waste management, a field experiment was conducted to evaluate the application of biosolids as organic fertilizer in a corn cultivation crop. In addition, to achieve food security, the study aimed to assess metals concentrations in soil and maize plants and enrichment factors (EF) for soils and plants.
Method Four sites with a biosolids application were studied and compared against a control. Physicochemical properties of soils and heavy metal contents were evaluated after one year of application of biosolids. Metal concentrations, average kernel yield and biomass were measured in corn plants.
Results The results demonstrated that the biosolids increased the content of organic matter, nitrogen, phosphorus, and exchangeable bases in the soil. In addition, the concentration of heavy metals in soils with biosolids was higher than in soils without treatment, and the concentration of heavy metals in the corn kernels did not exceed the maximum recommended limits. However, EF values showed a considerable contamination grade due to the accumulation of metals.
Conclusion Some of the physical and chemical characteristics of soil were improved by incorporating biosolids, but the metal content in the soil increased. Also, the application of biosolids increased the plant height and corn yield. Therefore, biosolids can be used as organic fertilizer sources; however, it is necessary to carry out periodic evaluations to ensure low levels of enrichment in crops and soil, thus guaranteeing the safety of biosolids as soil fertilizers.
Abstract: Purpose Poultry litter (PL) and basalt rock powder (BRP) are raw materials highly produced in some Brazilian regions. The association of these products can generate greater added value for the agribusiness chain and be a sustainable source of fertilizer.
Method The experiment consisted of an incubation trial over time for chemical characterization of the materials. The treatments used were the mixtures 10, 20, 30, 40, and 50 g of BRP per 100 g of PL, as well as the pure PL and BRP controls. During the incubation period, the atmospheric releases of CO2 (40 days) and N-NH3 (43 days) were determined. At the end of the process, the chemical quantification of the essential elements in all treatments was performed.
Results In our study, we observed that adding 30% of BRP to the PL promoted less volatilization and a faster stabilization of the N-NH3 release, associated with a greater release of CO2 into the atmosphere. The extractable P and K contents decreased starting with treatment T30. The T10 treatment showed the highest total nutrient contents, although it showed no statistical difference for some nutrients when compared with PL.
Conclusion The use of up to 30% of BRP in PL can be an economic and advantageous alternative for sustainable agricultural fertilization.
Abstract: Purpose Coir dust was utilized to manufacture soilless mixture for ornamental plant reproduction. Coconut coir provides more air and moisture to the root zone. Growing medium with coir does not shrink from container walls upon drying.
Method This study was performed in a greenhouse, Institute of Agricultural Research, University of Zabol during 2019-2020; the experiment carried out on a completely randomized design with 4 treatments, 8 months of measuring and 3 replications. Treatments had contained equal volume ratio of coco peat+ rice hull; coco peat + spent mushroom compost, cocopeat + leaf mold, coco peat + perlite. Measurable factors like plant height, stem diameter, number of new leaves, fresh and dry weight of leaves and the amount of chlorophyll were assessed for comparison of pothos growth, and finally plants had compared as stated by their general form and morphology too. Characteristics were analyzed with SPSS software and mean comparisons were represented by Duncan test in P≤ 0.05.
Results The findings showed that the variables such as substrate, months of measuring and their interplays had significant effects on all factors (except stem diameter). Mainly, media containing leaf-mold characteristics such as plant height, leaf number and leaf area were better than the others. The results of cocopeat + spent mushroom compost were nearly similar to cocopeat + leaf-mold, but two other media didn’t show good growth after 8 months. On the other hand, growth rate of the plants improved by warming the air from autumn to summer and the most growth rate were related to July.
Abstract: Purpose The aim of this work was to study the effect of adding sugar beet molasses on the biochemical properties, microbial flora, fermentation quality, and aerobic stability of prickly pear cactus (Opuntia ficus-indica) waste silage.
Method Molasses (0%, 2%, 4%, 6%, 8% and 10%, w/w) was mixed with the cactus fruit scraps, straw and wheat bran.
Results The dry matter content, pH, total and reducing sugars of the pre-ensiling material increased after adding different percentages of the beet molasses (P < 0.05). During fermentation, we observed substantial protein and sugar degradation. All silage treatments reached stable pH values (pH 4.3-4.6). Among all the concentrations, the 10% beet molasses treatment underwent the highest lactic acid fermentation. Accordingly, the pH drop was higher in the 10% concentration (1.13 units) compared to lower beet molasses concertation (1.03 units). Also, the 10% concentration has the highest number of lactic acid bacteria. The number of yeast and total aerobic mesophiles decreased continuously during silage. Moreover, during post-fermentation testing, the yeast multiplied little for the 10% concentration of beet molasses.
Conclusion The results show that the addition of molasses has a significant effect on silage characteristics of prickly pear cactus.
Abstract: Purpose Food insecurity and poverty are common challenges in arid and semi-arid regions. Diversification into low input agriculture like mushroom cultivation can help address these challenges. However, recommended mushroom substrates in Kenya (rice and wheat straws) are not widely available cheaply. Crop residues found in semi-arid areas can serve as alternative substrates, but their efficiency has not been adequately evaluated. This study evaluated the potential of various agro-waste materials as alternative substrates for cultivation of phoenix oyster mushrooms (Pleurotus pulmonarius) in semi-arid regions.
Method Five agro-waste materials and their combinations were tested: maize stalks, beans straw, maize cobs, rice straw, and Melia volkensii leaves. The study assessed the effects of these substrates on different mushroom growth and productivity parameters. The experiment was set in a randomized complete block design, under relative humidity of 80 - 90% and temperatures of 23 - 24°C, over a 75 day period.
Results Substrates containing M. volkensii failed to colonize fully except in their combination with bean straw, which yielded little. Yields varied significantly by substrate, ranging from 136.2 g/kg of wet substrate in bean straw + Melia volkensii to 434.9 g/kg of wet substrate in rice straw. Mushroom yields from maize stalks + bean straw and maize stalks + maize cobs substrates were not significantly different from those of rice straw, the control substrate.
Conclusion The study showed that combinations of maize stalks, bean straw and maize cobs are suitable alternatives to rice straw, as substrates for oyster mushroom production.
Abstract: Purpose Soil acidity and nutrients deficiency are the major constraints causing low crop yield and food insecurity in the highlands of Ethiopia. A field experiment was conducted in northwestern Ethiopia during 2018 and 2019 cropping seasons to study effects of compost and lime application on soil properties and wheat yield.
Method The treatments consisted of three compost levels (0, 3 and 6 t ha-1) and three lime rates (0, 1 and 2 t ha-1) arranged in a randomized complete block design with three replications. Before planting and after harvest, soil samples were collected from each experimental plot to analyze soil properties.
Results Combination of lime and compost significantly (p<0.05) increased soil pH, soil organic carbon, total nitrogen, available phosphorus and exchangeable base cations. In contrast, exchangeable acidity and aluminum levels decreased substantially compared to individual application of amendments. Compared to the control, application of 2 t ha-1 lime, 6 t ha-1 compost alone and their combination increased wheat grain yield by 24.6%, 42% and 97.5%, respectively. Besides, the combined application of compost and lime provided the highest net benefit (1915.90 US$ ha-1), which was noticeably greater than the control (1034.44 US$ ha-1).
Conclusion The application of lime and compost in combination is an effective option to curb soil acidity while enhancing soil nutrients availability and crop yields at lower input costs. However, to determine the application frequency, long-term effects of compost and lime in combination on acidic soil properties and crop yield need to be investigated through further research.
Abstract: Purpose A study was carried out on composting pistachio hull aided with chemical fertilizer. Recycling of pistachio wastes is one of the major agricultural way in pistachio producing country.
Method The collected pistachio hull was allowed to decompose either naturally through composting or with the addition of chemical fertilizers. Biological and chemical properties with organic matter were monthly measured in both composting methods. The data was analyzed in a completely randomized design. Mean values were compared using Duncan's multiple range test in SPSS software (p < 0.05).
Results Increasing chemical fertilizers reduced the microbial density and diversity during the composting, the concentration of the elements in both composting methods increased over time. The EC in both methods decreased over time from 6.95 to 6.17 dSm-1 in natural composting and 6.95 to 4.85 dSm-1 in adding of chemical fertilizers. The C: N ratios of the produced compost was found to be lowered in adding of chemical fertilizers during composting compared with those naturally composting treatment.
Conclusion Addition of chemical compounds to the primary wastes could accelerate and improve the decomposition process and lead to faster composting as well as nutritional enrichment and lower C: N ratios, but it reduced microbial density and changed their diversities.
Abstract: Purpose Undecomposed rice straw incorporated into the soil can negatively impact rice growth, but it is also an important source of soil carbon. The objective of this study was to evaluate whether the addition of weeds that naturally grow in rice paddy ecosystems could accelerate the decomposition rate of rice straw. The microbes that contribute to the decomposition process were also investigated.
Method Trifolium pratense (clover) and Rumex obtusifolius (bitter dock) both alone and in combination were decomposed along with rice-straw litterbags in rice paddy soils. The rice-straw decomposition rate was measured using the weight changes of the litterbags. The rice-straw carbon-to-nitrogen ratio and microbial abundance (fungi and bacteria) were also measured, as well as the soil respiration rate every seven days.
Results The addition of weed residues increased the soil respiration rates, but it did not influence the rice-straw decomposition rate. However, the carbon-to-nitrogen ratio of the remaining rice-straw and the fungi-to-bacteria ratio in the soil were both affected by the presence of the weeds, and the magnitudes of the effects were dependent on the carbon-to-nitrogen ratio of the added weeds.
Conclusion Given that the addition of weeds altered the quality of the remaining rice straw and the soil microbial community composition, longer term studies are required to determine whether the addition of weed residues primes the rice straw for the later stage of decomposition.
Open Access journal
[18 journals]
