International Journal of Recycling of Organic Waste in Agriculture
Volume:11 Issue: 3, Summer 2022

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Sole BR could entirely substitute sole RS as a substrate for the production of Pleurotus ostreatus.

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.

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.

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.

Organic fertilizer from chicken carcass was able to increase the production components of soybean as well as to increase the soil P availability.

This study evaluated the response of hot pepper (Capsicum annuum var. Red chili) towards cow vermicompost application under field conditions.

Cow vermicompost was supplied in four levels (0, 5, 10, and 15 t ha-1) across the two growing seasons in 2017 and 2018.

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.

It was concluded that the application of vermicompost had a significant impact on vegetative and reproductive growth and fruit quality of hot pepper.

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.

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.

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.

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.

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.

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.

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.

Composting manure with phosphoric rock could be a low-cost source of macronutrients, minerals, and microorganisms to promote soil health and crop yields.

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.

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.

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.

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.