INTERNATIONAL JOURNAL OF RECYCLING OF ORGANIC WASTE IN AGRICULTURE
Year:2017 | Volume:6 | Issue:1|Papers Count:9

urpose: Chemical decomposition was studied as a potential method for the rapid conversion of waste to organic fertilizer.Methods: Chemicals were screened, and process parameters were optimized. The physicochemical properties, phytotoxicity, and manurial efficiency of the product were assessed. A prototype machine was fabricated for the operation.Results: Chemical treatment of ground fresh waste with HCl (0.25 N, 50 ml kg-1) for 30 min followed by KOH (0.5 N, 100 ml kg-1) for 30 min at 100 oC, and ambient pressure yielded a product that could be used in place of conventional organic manure. Only 8–14 h were required to complete the entire process. No by-product or leachate was produced. The quality of the product was comparable to that of conventional composts, except for the absence of microorganisms. The fortified organic fertilizer enhanced the yield of vegetables in pot trials. The process and the prototype machine were found beneficial by a public evaluation.Conclusions: The new thermochemical waste processing method provides a quick and sustainable solution for hygienic waste disposal and the production of organic fertilizer.

Purpose: Effect of various combinations of potting substrates was assessed to enhance vegetative growth, plant productivity and mineral composition of Caladium bicolor.Methods: Different substrates like leaf compost, farmyard manure, coconut compost, compost and perlite were used in different combinations with silt. Bulbs were sown in pots filled with different combinations of potting substrates, which were arranged under completely randomized design (CRD), with three replications, and totally there were ten treatment combinations.Results: Application of different treatments of growing media either alone or in combinations led to considerable improvement in plant growth characteristics as compared to respective control. However, response differed according to the type of media manipulation. The highest stimulatory effect with maximum plant growth in terms of early sprouting, plant height, leaf area, chlorophyll contents, fresh and dry weights of tubers was observed in plants treated with silt? leaf compost? perlite combination; this combination significantly enhanced plant growth (30-150%) as compared to control. In case of NPK and protein contents, treatment combination of silt? leaf compost. coconut compost was greatly affected which lowered the pH, increased available organic matter and consequently maximized nutrient uptake by the plants.Conclusions: The best selection of conventional organic and inorganic potting media is the key to successful mass propagation of containerized plants. Generally, it could be concluded that application of potting mixes with silt, perlite, leaf composts and coco-based residues is a good cultural practice to improve the crop productivity and provide a better growing environment for plants.

Purpose: Faecal sludge (FS) has been co-composted with many organic solid wastes globally. Agricultural wastes, such as oil palm empty fruit bunches (EFB) and cocoa pod husks (CPH), have received very little research attention as far as combining with FS is concerned. This study aimed at co-composting these wastes at different ratios to produce safe compost for use as soilless medium for raising tomato transplants.Methods: Dewatered FS (DFS) was mixed with shredded EFB and CPH at five different ratios: 1DFS: 1EFB, 1DFS: 1CPH, and DFS: EFB: CPH in ratios of 1: 1: 1, 2: 1: 1, and 2: 2: 1 and composted for 3 months. Select physicochemical parameters and pathogens were monitored every fortnightly and 3 weeks, respectively.Results: Maximum temperatures obtained ranged 46.8–54.5 oC. Though these temperatures were lower than sanitizing temperatures prescribed by USEPA, no E. coli was found in any of the piles at the end of composting. The ratio 2DFS: 2EFB: 1CPH was found to be the safest formulation and hence was used to grow tomato under greenhouse conditions. Tomato seeds were sown in three different growing media: 100% FS-based compost, 100% rice husk biochar, and 50% FS-based compost–50% rice husk biochar mix.Conclusion: Results showed that FS-based compost was a suitable growing medium for tomato. Further studies into the optimal rate and frequency of application of compost teas on tomato are recommended.

Purpose: The investigation of the phytoextraction potential of three vegetable plants grown in soils amended with decanter cake.Method: Pot experiments were conducted to investigate the response of decanter cake composition on the phytoextraction of metals (Mg, Zn, Ni and Cu) by lady’s finger, tomato and brinjal plants. The phytoextraction properties of these plants were determined by calculating the bioconcentration and translocation factors at different decanter cake amendments (10, 20 and 30%).Results: Results indicated that in all three plants, there was no transfer of excess metal ions from the control soil or amendments to the fruit portion as evidenced by bioconcentration factor (BCF). In addition, substantial amount of the metals was found to be accumulated in the roots and shoots, which depicts the phytoextraction ability of these vegetable plants. The translocation factors (TF) of the three plants were found to be higher than control plants. The accumulation of metal ions did not exceed the permissible standards for vegetables thus rendering the fruits safe for human consumption.Conclusion: On the basis of significant findings, lady’s finger, tomato and brinjal plants were not found to be suitable for phytoextraction of metals as both BCF and TF were not greater than 1.

Purpose: Declining water resources, increasing drought period and increasing irrigated area cause a shift to deficit irrigated production which is not based on full water requirement. This study was conducted to investigate the impacts of two different deficit irrigation methods, including traditional deficit irrigation (TDI) and partial root-zone drying (PRD) on water use efficiency (WUE) in corn cultivations located at the lands close to the Shahrekord wastewater treatment plant.Methods: A factorial design was employed, consisted of fifteen treatments and three replications. The first factor was three water applications, including 60, 80 and 100 (control) percent of plant water requirement. The second factor was three water sources, including 100% fresh water (FW), 50% water and 50% wastewater (5050), 100% wastewater (WW). T-Tape irrigation type system was used for irrigation of corn (Zea mays L.). The third factor was water management in three levels: full irrigation (FI), PRD and TDI.Results: The result showed that dry and fresh weight, leaf area index (LAI), dry biomass percentage and WUE were affected by water requirement at 5% probability level expect of height plant that is affected at 1% probability level. Water quality was affected on all the study indicators of corn plant expect of WUE. WUE among PRD by deficit irrigation treatments were higher than TDI and it was the minimum in FI. The dry and wet weight and LAI were maximum at FI and then PDR80 than TDI80. The height of corn plants were high at FI and TDI80 than PRD80.Conclusion: Finally, wastewater application in treatment named 5050-PRD80 and 5050-TDI80 compensated water deficit in WUE, LAI and dry biomass percentage. PRD method recognized more suitable than TDI for corn plants.

Purpose: Microbial pathogens can lead to health problems and disease transmission. Present study aimed to evaluate the microbial quality and quantity of vermicompost production and to compare to the current Iranian standards to protect public health and environmental concerns.Method: This is a pilot-scale experimental study conducted in the Public Health laboratory of Shahid Sadoughi University of Medical Sciences. The samples included organic municipal solid waste, cow manure and wastewater treatment plant sludge which are used for vermicompost production. The samples are mixed as cow manure–organic waste and cow manure–sewage sludge in two reactors. Microbial tests such as fecal coliforms (FC) and parasite egg (Ascaris) were carried out during start, processing and curing time with duplication analysis in 56 days. Totally, a number of 128 samples was analyzed. Analyses were conducted according to standard methods. Data analysis was conducted through one-way ANOVA and Duncan tests.Results: The results showed a significant reduction in number of FCs in cow manure–organic waste so that the number of 350, 000 MPN/g in the raw sample decreased to 800 MPN/g within 8-week period, also FC in the case of cow manure–sewage sludge was achieved to 2400 from 6, 500, 000 MPN/g. In two cocomposting cases, the parasite eggs were completely removed in the second week.Conclusion: The results showed vermicomposting as a feasible method to convert waste into fertilizer humus in agriculture which also enables to achieve Iranian class A compost standard.

Purpose: A field study was conducted at Dire Dawa, Eastern Ethiopia, with an objective to find out an optimum combination of inorganic (NP) fertilizer and excreta-based vermicompost for best economic yield and quality of tomato and to assess their effect on selected physicochemical properties of amended soil after crop harvest.Methods: The experiment consisted of eight treatments where the mineral (NP) fertilizer and the excreta-based vermicompost were combined in different proportions being arranged in a completely randomized block design replicated three times.Results: Growth, yield and quality attributes of tomato as well as the post-harvest soil nutrient status were markedly influenced by the nutrient treatments. The highest values for the various growth, yield and quality attributing parameters were recorded for the treatment combination consisting 75% of the recommended rate of NP fertilizer ? 11.25 ton ha-1 vermicompost (T6), this treatment was also observed to have the highest net benefit with acceptable economic return as well as a fairly high residual soil nutrient status. Following this treatment, is the integration of 50% of recommended rate of NP fertilizer? 7.5 ton ha-1 vermicompost (T3) which surpassed the sole mineral fertilizer and vermicompost in terms of the crop’s yield and its economic return.Conclusion: 25–50% of the recommended rate of chemical fertilizer can be supplemented through vermicompost. However, in order to generate more reliable information, there is a need to conduct more such studies using more integration ratios of these nutrient sources (NP fertilizer and vermicompost) at various soil and agro-climatic conditions.

Purpose: Wastes were composted and applied as the soils amendment to improve soil fertility and crop productivity. The study aimed at assessing the nutrient uptake and growth of spinach (Spinacia oleracea L.) grown in soils amended with cow manure after a co-composting process.Methods: Sandy loam and silt loam soils were amended with cow manure after co-composting with poplar leaf litter at 1: 0, 1: 1, 1: 2 and 1: 3. The compost was applied to soil at the rate of 20 t ha-1. Spinach was grown for 8 weeks and then harvested to measure plant shoot biomass. Spinach shoot samples were digested and nutrient contents in the shoots were determined.Results: Co-composted manure significantly improved the growth and nutrients availability to the spinach. Dry biomass, P and K contents in spinach shoot varied among manure: leaf litter ratios: 1: 0\1: 1\1: 2\1: 3. Conversely, N, Zn, Fe, Cu and Cd contents in spinach shoot reduced with the manure amendment with increasing amount of leaf litter. Water extractable micro-elements in the post-harvest soils were found in the order of Zn [Fe [Cu [Cd. Co-compost amendments increased the P and K availability except N, NO3 and NH4 in the post-harvest soils. Trace elements in the post-harvest soils reduced with leaf additives in the compost.Conclusions: Co-composted cow manure with leaf litter proved to be superior in terms of bioavailability of plant nutrients over the composted manure without leaf litter. This may also assist in mitigating the environmental contamination of heavy metals in the farm lands.

Purpose: Flower waste dumping in landfills and other disposal sites is causing major environmental issues due to its highly biodegradable nature. Instead, flower waste can be successfully composted for its higher nutrient value. Therefore, this study evaluated the pile composting of flower waste with different combinations of cow dung and saw dust to produce stabilized compost.Methods: Five agitated piles of flower waste mixture were formed in trapezoidal shape to perform the composting. Pile (P0) was a control experiment, which contained 100 kg flower waste. The quantity of flower waste mixture with cow dung and saw dust in the other Piles was a total of 100 kg i.e. P1 (50: 40: 10) kg, P2 (60: 30: 10) kg, P3 (70: 20: 10) kg and P4 (80: 10: 10) kg, respectively.Results: Temperature above 50 oC was observed in all the piles except in P0. Physico-chemical characteristics of compost showed a stabilized compost obtained by proportionate mix of flower waste, cow dung and saw dust.Pile P2 was observed with pH 7.23 and electrical conductivity 3.98 mS cm-1, total organic carbon 30.9%, total nitrogen 2.31% and C: N ratio 14, thus a good proportion for compost amongst all the piles.Conclusions: Appropriate proportion of waste mixture played an important role in providing favorable conditions for the microbial transformation of flower waste to stabilized compost. Temperature influenced the growth of microbes and maximum temperature was helpful in fast degradation of organic matter. Finally, flower waste with a combination of cow dung and saw dust was found to be successful during pile composting.