International Journal of Recycling of Organic Waste in Agriculture
Volume:8 Issue: 1, Winter 2019

Intensification of rice cultivation to meet the growing demand has imbalanced the nitrogen level in soil. Amendments of inorganic fertilizers increase yield, but at the same time affects the environment. Hence, different amendments are to be investigated which acting sustainably on soil and the environment upholds yield gains.

A study was carried out on acidic sandy loam soil in the irrigated summer seasons of the years of 2015–2016 and 2016–2017 to examine the effects of various amendments on rice growth, soil health and yield. The applied amendments were inorganic fertilizer blended with crop residues, farm yard manure and compost made of daily household green wastes.

The highest yield of 53.33 ± 2.09 Q/ha was recorded with application of inorganic fertilizer blended with compost and the lowest yield of 32.71 ± 3.09 Q/ha without amendment. Strong positive correlations were found between soil moisture and volumetric water content (0.982 at p < 0.001), manganese and copper (0.900 at p < 0.001), whereas available phosphorus and manganese showed a strong negative correlation (− 0.901 at p < 0.001). Performing stepwise regression analysis, yield was found affected mostly by soil moisture and total carbon out of evaluated 17 soil traits.

The inorganic fertilization blended with the compost increased rice yield by 13.61% over inorganic fertilizer but a higher yield associated with compost demoted total nitrogen contents in soil, leading to lower soil nitrogen fertility and providing a negative feedback to sustainable agriculture. More research is required on compost development and application in different rice agroecosystems.

A suitable strategy for bioconversion of agricultural waste into quality organic manure and its efcient utilization was assessed in the hilly ecosystem of Northeast India.

Pits were dug in terrace lands and flled with chopped plant biomass (rice straw, maize stover and mixed weed biomass) with alternate layers of cow dung at 3:2 ratio. The treatment consisting of control (plant biomass+cow dung), plant biomass+cow dung+earthworm (Eisenia fetida) (with or without poly lining in the pit) and plant biomass +cow dung+earthworm+cellulose-degrading microorganism (Pseudomonas sp.) (with or without poly lining in the pit) was used for the bioconversion process.

Combined inoculation of E. fetida and Pseudomonas sp. with poly lining in the pit signifcantly enhanced compost recovery (29.8%), cellulase activity (55.2%) and the C:N ratio (1.9%) as compared to control. Signifcant achievement in yield components and nutrient status in soil was observed after combined application of compost with 50% recommended dose of fertilizer.

The current investigation established dual inoculation efect of E. fetida and Pseudomonas sp. with poly lining in the pit as a suitable technology for faster decomposition and efective bioconversion of agricultural waste into quality organic manure. A treatment imposed with such organic manure will be supportive in enhancing crop production as well as improving soil health.

Rice straw is a waste product from the harvesting of Oryza sativa L. It is recurrently burned resulting in producing overheating, soil degradation, and air and water pollution.

A pot experiment was designed under polyhouse conditions to evaluate the efects of rice straw as a substrate with Sorghum bicolor (L.) Moench, Hordeum vulgare L. and Triticum aestivum L. as diferent host on mass multiplication of Glomus mosseae.

AM fungi multiplication was greatly infuenced by the presence, concentration (0, 25, 50 or 100 g/pot) and type of substrates. Soil amendment with compost rice straw proved more suitable for AM fungal multiplication over dry substrate. Sorghum bicolor acts as a suitable host and produced the most inoculum followed by Triticum aestivum.

Assessment of the efects of substrates and hosts on the multiplication of pure culture of AM Fungi is an important prerequisite condition for large-scale agricultural application and exploration as biofertilizers.

A study was conducted to extract calcium chloride from eggshell and also to check the efect of commercially available and extracted calcium chloride on quality characteristics of fresh-cut fruits.

Eggshells were mixed with a hydrochloric acid solution and stirred occasionally until no gas bubbles were observed (3 h). The mixture was centrifuged at 3500 rpm for 10 min at 4 °C, the supernatant was separated and heated to 110–115 °C until dried, this yielded calcium chloride crystals or eggshell calcium chloride. The fresh-cut fruit cubes were separately dipped in a solution of 2% calcium chloride extracted from egg shell and 2% commercially available for 5 min. The cubes are packed in polypropylene plastic bags and stored at 5 °C. Analyses were done at 5-day intervals for a time period of 25 days. The microbial count, physical (frmness, weight loss and color), chemical (pH, titratable acidity, total soluble solids, DPPH, reducing sugar, total phenolic content, and ascorbic acid content), and sensory analysis were determined at regular interval throughout the storage period.

Calcium chloride extracted from egg shell was capable to maintain shelf-life for 15 days, whereas commercial calcium chloride was able to maintain shelf-life for 20 days. This shows calcium treated fresh-cut fruits have an improved and enhanced shelf-life than control (non-treated samples).

The study proved that dipping fresh cut fruits in CaCl2 solution (extracted from eggshell and commercially available) extend its shelf-life for 15 days.

This research aimed to produce biochar from cofee residues (CR) as well as to develop the guidelines for using it as a fuel and a soil amendment.

Initial properties of cofee residues have been characterized before experimenting with a biomass kiln, designed for use in biochar production. By carbonization method, using biomass kiln at the temperature of 350–550 °C with 45 min of the reaction time.

It was found that the biochar made from cofee residue (BCR) possessed a high heating value and fxed carbon (7360 cal/g and 77.77%) whereas it produced such a low amount of ash, moisture and volatile matter (6.18, 4.16 and 11.89%, respectively). The atomic ratio of H/C (0.71) and O/C (0.28) ratios of BCR were shown that were in the range of coal. Moreover, BCR showed adsorption of iodine (612.28). According to the analysis of the chemical properties of BCR, its pH, EC, Nitrogen, Phosphorus, Potassium, OM and C/N ratio were 9.9, 1.66 dS/m, 3.1, 1, 1.7, 19.5 and 28.9%, respectively.

From the results of this study, it can be concluded that BCR could be potentially used not only as an efcient source of the fuel production but also suitable material for soil amendment due to its direct contribution in nutrient absorption along with retardation of nutrient leaching, thereby helping improve the efcacy of nutrient use and increase crop yields.

The objectives of this study were to assess the black soldier fy larvae (BSFL) composting potential and to analyse the quality of organic fertilizer produced for agricultural purposes.

The waste biodegradation was determined by varying waste feed treatment (2, 2.5, 3.0, 3.5, to 4 kg) and control treatment of (2 kg) of heterogeneous mixture of municipal organic solid waste from market, restaurant and households. Each of the setups received equal number of viable larvae (i.e. 2000) which were 5–6 days old. To analyse the nutrient concentration of the compost residues with BSFL, the substrate and fnal compost were evaluated based on the levels of NPK as well as the C:N ratio. To evaluate the toxic levels of the fnal compost in terms of heavy metals, the presence and levels of As, Cd, Fe, Pb and Ni were investigated.

The analysis showed that there was high percentage increase of nitrogen, phosphorus and potassium levels, i.e. 41.2% (SD ± 0.71%), 32.4% (SE ± 0.2%) and 77.1% (SE ± 0.19%), respectively. It was found that the larvae degraded more than half of the total substrate within 2 weeks. The study showed a decrease in heavy metal concentrations after larvae composting.

The study revealed that the concentration of NPK increased signifcantly among the treatment groups. The study further revealed that some of the heavy metals under investigation had reduced to an acceptable level according to the standards of both local and international regulatory bodies.

Adoption of co-composting to treat swine slurry can reduce risks of pollution and produce organic fertilizer. Wood shavings and sawdust are the usual bulking agents used in such treatments, however planted forest is a feedstock source of slow renewability rate. Thus, the prospection of alternative biomass feedstock in regions of high animal density, may enable the pig slurry co-composting. Therefore, this manuscript describes a case study carried in Southern Brazil, region that houses 56% of Country’s swine herd, and where ryegrass is a common winter cover crop.

A study was conducted to evaluate the efect of increasing shares of ryegrass straw in the bulking agent of swine slurry co-composting, as follow: wood shaving (W), ryegrass straw (S) and blends (W/S=50/50 and 30/70). Composting evolution was monitored during 85 days by measuring daily the temperature and emissions of CO2, CH4 and NH3, afterwards at 100th day the resulting composts were characterized.

The increase in straw shares, elevated temperature peaks (>60° C), accelerated the biomass stabilization from>85 to 65 days, and produced fertilizers with higher nutrient content due to its higher biodegradability, though NH3-N emission increased up to 10%. The maintenance of a share of wood shavings can mitigate that emission, besides improve the stability of pile temperature and decrease leaching.

Although ryegrass straw can total or partially substitute wood shavings in swine slurry co-composting, substrates blends were more promising. Further studies approaching management adjusts are required to prevent increasing the emission of NH3-N and leaching.

Traditional methods of composting are limited in timely production of good-quality compost due to recalcitrant nature of materials of plant origin. This study focused on evaluating the use chicken and donkey manure as starter cultures to biostimulate bioconversion of rice straw into bioorganic fertilizer. Use of starter cultures would enhance composting as a strategy for rice straw management to enhance soil fertilization and reduce environmental pollution.

In this study, chicken manure and donkey manure were used as starter cultures to enhance bioconversion of recalcitrant and abundant rice straw in Mwea, the main rice-producing area in Kenya. Treatments of the study included rice straw co-composted with chicken manure (T1), rice straw co-composted with donkey manure (T2) and a control (T0) consisting of un-treated rice straw. Temperature, pH and electrical conductivity (EC) were monitored throughout the composting period. Resultant compost types were characterized in respect to their macro-nutrient concentrations, cation exchange capacity, pH and heavy metal content.

Levels of temperature, pH and EC among the treatments of the study revealed signifcant diferences at 5% level of confdence using Tukey’s test. The three resultant compost types obtained were also physicochemically diferent as revealed by analysis of variance of cation exchange capacity, phosphorus, nitrogen and carbon content.

Results indicated that use of chicken and donkey manure signifcantly improved the composting process and the quality of resultant compost.

This research work described the efect of organic waste (poultry manure) on soil cumulative infltration rate (CIR), soil organic matter (SOM), and maize performance on two contrasting alfsols of southwestern Nigeria.

Six treatments of poultry manure were applied in split at 0 Mg/ha, 2 Mg/ha, 4 Mg/ha, 6 Mg/ha, 8 Mg/ha, and 10 Mg/ha, in replicate under a completely randomized design to clay loam (CL) and sandy clay loam (SCL) soils, at 3, 6, 9, and 12 weeks after the initial application.

The results showed signifcant increases (P<0.05) in CIR, SOM, and maize performance compared to the control in both soils. Poultry manure at 10 Mg/ha recorded the highest SOM which was signifcantly (P<0.05) diferent from other application rates in both soils. The mean values for SOM in SCL were between 0.67 and 3.75% for 0 Mg/ha and 10 Mg/ha, while the mean values recorded for CL were between 0.80 and 4.35% at 0 Mg/ha and 10 Mg/ha. Poultry manure reduced CIR in the SCL, but improved CIR with increasing rates on CL. Poultry manure at 4–10 Mg/ha increased the maize shoot biomass signifcantly (P<0.05). However, the application rate of 6 Mg/ha manure recorded the highest fresh shoot biomass, while 8 Mg/ha increased dry shoot biomass in both soils.

This study indicated that poultry manure applied at 10 Mg/ha gave the best results in improving CIR, SOM, and maize performance on diferent soil types.

Rapid nutrient depletion in soils is one of the major problems that afect food production and food security in SubSaharan Africa. Studies have linked the growth of food crops with seasonal variation and diferences in weather conditions. This study was conducted to assess the efects of various organic fertilizer formulations (OFFs) on the growth and yield of selected crops (Zea mays L.; Glycine max, TX 114 and Dioscorea rotundata Poir) during rainy and dry seasons to ensuring climate-smart agriculture.

The OFFs used were plant-based (PB), animal-based (AB), rock-based (RB), organic mixture (OM-mixture of PB, AB and RB), synthetic/chemical (SC) while ordinary compost without fortifcation served as control. Efects of OFFs on growth parameters (number of leaves, plant height, stem girth, leaf area, and crop yield) of maize, yam and soybeans were assessed in plot experiments across the two seasons.

The RB gave highest growth performances in maize and soybean plots at both seasons when applied at 2.5 t ha−1. It also improved yam growth when applied at 2.5 t ha−1 (rainy season) and 3.0 t ha−1 (dry season) more than any other fertilizer. The largest yield of maize in the dry season was obtained from plots with PB at 2.0 t ha−1. The AB at 2.0 t ha−1 gave the largest soybean yield in the rainy season.

Organic fertilizers enriched especially with rock-based and plant-based materials have the potential to ameliorate the threat of climate change and seasonal variation to food security

Biochar application could be a sustainable way to enhance the nitrogen fxation in Bambara groundnut and other legumes. The research was conducted to study the efect of rice husk biochar and the Christmas Island Rock Phosphate application on the performance of Bambara groundnut in the study area.

Two levels of rice husk biochar (0 and 10 t/ha) and four levels of Christmas Island Rock Phosphate (0, 20, 40 and 60 kg P2O5/ha) were factorially combined to make a total of eight treatment combinations which were laid out in a randomized complete block design (RCBD) with three replicates. Data were collected on nitrogen content and fxation of the crop.

Application of rice husk biochar increased the total mean of nitrogen content and N fxed by the crop from 120.0 and 90.9 kg/ha to 147.6 and 114.1 kg/ha, respectively. However, the efect of rock phosphate application on the nitrogen content and fxation of the crop was not observed.

Rice husk biochar application at 10 t/ha alone was sufcient for nitrogen content and fxation of the crop. This implies that farmers in the study area can apply rice husk biochar at 10 t/ha to enhance the performance of the crop

The benefcial efects of liquid humus applied to plants are well reported in the literature; however, studies of liquid humic application in the production and quality of garlic culture are practically nonexistent. The objective of this work was to evaluate the efects of foliar application of a liquid humic extract from vermicompost (HEVC) that is well characterized by solid-state 13C NMR on garlic production and fruit quality under feld conditions.

After 45 days in the feld, garlic plants received foliar applications of HEVC at three diferent dilutions: 1:40, 1:60 and 1:80 (v:v). Humic substances (HS) in HEVC were characterized by 13C NMR CP/MAS spectroscopy. At 125 days after planting, the plants were collected, and growth and production parameters were determined: quantity of garlic cloves, fresh and dry bulb, diameter of garlic cloves and bulb, as well as parameters of fruit quality including caliber, frmness, acidity, brix, pungency, carbohydrate and protein contents.

The structure of HS in HEVC is composed mainly of carbohydrates and peptides as well as lignin fragments, explaining the stimulus efects on plant metabolism. The foliar application of HEVC improves the productive, commercial and internal quality parameters of fruits when compared to the control treatment. The HEVC foliar application in 1:40 v:v ratio was the most promising treatment in terms of increases in fruit quality indices, promoting improvements in bulb caliber, numbers of garlic cloves and internal fruit content.

The foliar application of HEVC benefts garlic production and fruit quality. The use of HEVC can be a sustainable alternative within the small-scale garlic phytotechnology package.

Persistence of herbicides in soil is a major concerning world issue due to their negative impacts on environment and human health. Laboratory and bioassay experiments were conducted to evaluate the efects of municipal waste compost (MC) and sheep manure (SM) on metribuzin degradation and phytotoxicity of this herbicide.

In degradation studies, soil samples were mixed separately with amendments at a rate of 2.5% (w/w) and metribuzin at a concentration of 5 mg kg−1 soil was used for fortifcation of selected samples. A liquid extraction method was chosen and fnal extracts were analyzed by HPLC. In bioassay study, the phytotoxic efects of diferent concentrations of metribuzin (0, 0.01, 0.05, 0.1, 0.2, 0.4, 0.8 and 1 mg kg−1 soil) on oilseed rape (Brassica napus L.) were evaluated.

The results indicated 88.8% degradation of metribuzin in MC during 120-day period followed by SM recording 72.2%, compared to non-amended soil where 59.8% of metribuzin were removed. The half-life was 119.48 days in nonamended soil as compared to 87.72 and 103.43 days in MC and SM application, respectively. MC was the most efcient treatment to accelerate metribuzin dissipation from the soil. Bioassay results showed that metribuzin residues had a negative efect on root and shoot biomass of oilseed rape. However, the root parameter was more sensitive than the shoot.

It could be concluded that application of organic amendments to agricultural soils is an eco-friendly strategy to improve soil conditions and non-target crop protection as well as the removal of herbicide residues from soil environment.

The nursery is the production of vigorous seedlings for field transplantation. Fertilization improves the quality of Moringa oleifera in the greenhouse. Thus, the effect of composts amendments on the survival rate and mineral composition of M. oleifera was studied.

A randomized complete block (RCB) design comprising fourteen treatments and twelve repetitions (pots referring to as repetitions), was led out in greenhouse. Varying compost receipts (0.1 kg, 0.2 kg, and 0.3 kg) were used and an increasing amount of a chemical fertilizer (NPK: 20:10:10) was added in some treatment at 25 days after sowing. Parameters such as germination rate, survival rate, biomass, and mineral composition of M. oleifera plants were assessed.

The germination rate was maximal (100%) in the combined treatment PM1 (0.8 kg of soil + 0.1 kg). A considerable reduction of germination rate and high plantlet mortality were observed in treatments that received chemical fertilizer, although the mineral components’ uptake in young M. oleifera plants was considerably improved. The highest dry root biomass was obtained from the treatments MF1 (0.8 kg of soil + 0.032 kg each of cow dung, goat, chicken manures + 0.003 kg NPK) and CM1 (0.8 kg of soil + 0.1 kg of cow dung compost), with, respectively, 0.62 g and 0.59 g per plant.

All composts types used in this study have appeared as appropriate amendments to improve the M. oleifera production in nursery, through an increase of the vigour and mineral composition of this valuable plant.

Purpose Climate change and global food demand in coming decades urge efective actions for more efcient uses of water and soil resources. This paper reports the preliminary fndings of a study assessing the potential of sheep scoured wool residues (SWRs) as soil amendments to enhance the physical and hydraulic properties of a sandy loam soil under rain conditions. Methods Two diferent SWRs were used: scoured residues (white wool, WW) and carbonized scoured residues (black wool, BW) at diferent SWRs/soil ratios (0.0, 0.5, 1.0 and 2.0%). Soil bulk density (BD), total porosity (TP), aggregates stability, aggregate size distribution, saturated hydraulic conductivity, and water retention properties were determined under rain conditions, in addition to rainwater balance (storage, percolation and runof). Results Both WW and BW, particularly at the high wool/soil ratio (2%), signifcantly reduced soil BD by 11.98% and 9.85%, respectively. Moreover, WW and BW increased TP by 16.45% and 13.57% and available water capacity by 6.5% and 18.1%, respectively. SWRs increased the formation of macro-aggregates and increased aggregate stability. The results of rainwater balance showed higher percolation percentages and less rainwater storage in the wool-treated soil. Conclusions The increase in water percolation is in line with the increased total porosity and the higher saturated hydraulic conductivity of wool-treated soil. Despite the high capacity of absorbing water, SWRs afected the water movement of the soil more than its water retention.

The aim of this study was to prove that the Fe-containing by-products (compost, sewage and lime sludge) have potential infuence on the correction of Fe defciency in sunfower and maize.

The physiological parameters used were the dry matter (DM), the relative chlorophyll content, and the content of photosynthesis pigments (chlorophyll a, chlorophyll b and carotenoids).

The results showed that sewage sludge was efective even when applied at low concentration (2 g L−1) for both sunfower and maize plants. In maize, however, chlorophyll a was the only pigment induced after sewage sludge treatments in contrast to sunfower, which could be the reason for lower DM in maize. Compost could only be efective when applied at higher concentrations (4 g L−1) for sunfower because of its low-Fe content, further showing that maize plants require more Fe. Despite its high-Fe content, lime sludge could not be efective in alleviating Fe defciency for both sunfower and maize plants because of its high pH, which makes Fe unavailable for uptake by the plants.

Although the investigated by-products can be hazardous depending on their origin, their use as micro-element fertilizer can be a very economical way of utilization in the agricultural felds, which may limit the use of high quantities of expensive Fe-containing fertilizers. Among the three waste products, sewage sludge application proved to have a great potential of correcting Fe defciency by inducing accumulation of the photosynthesis pigments, leading to high photosynthesis and eventually high DM.

Nitrogen loss as ammonia (NH3) in a waste cocoa pod co-composting process was determined following the addition of three potential chemical amendments that could lower NH3 loss. Further, amended compost products were assessed for quality and possible phytotoxicity in a pot experiment.

Pod borer damaged cocoa pods were co-composted in lab-scale vessels under ambient conditions with double superphosphate, phosphoric acid, and gypsum at 2%, 5% and 1% of fresh weight, respectively. NH3 emitted during composting was trapped in standard H2SO4 and determined titrimetrically. Composting mixtures were sampled on days 0, 7, 56 and 90 to monitor pH, total C, total N, and C:N ratio. Mature co-composts were incorporated to the soil at 20 t ha−1 and growth response of Chinese cabbage plants (Brassica rapa chinensis) assessed for the phytotoxicity.

The chemical amendments were inefective (p>0.05) in preventing loss of NH3 but the quality of composting mixtures were signifcantly (p<0.0001) improved. The manure compost generated had acceptable parameters (C, 31.2–31.9% and C:N ratio, 9–10:1) and were free from phytotoxicity for soil application as revealed by the response of Chinese cabbage crop.

Chemical amendments used in the co-composting process mainly modulated pH without any detrimental efects on quality. The results also demonstrated that the NH3 loss is insignifcant from the cocoa waste-composting process. Further studies are required with increased rates of acidifying amendments like phosphoric acid to further augment the quality of cocoa pod composts.

Industries are generating numerous amount and types of organic wastes to the environment. The aim of the present study was to investigate the efects of agro industrial wastes compost on soil physicochemical quality, soil microbial population, growth and yield of onion (Allium cepa L.) under feld condition .

The experiment was conducted in a completely randomized plot design at feld condition. Allium cepa L. was grown using fve diferent levels of agro industrial wastes compost, three diferent levels of inorganic fertilizers and three controls.

Compost amendment improved the soil pH, TOC, TKN, feld capacity (FC), permanent wilting point (PWP), and available water content (AWC), cultivable bacterial count and fungi. But no signifcant efect was found on electrical conductivity (EC), available phosphorus (P) compared to the control. Exchangeable Na, K, Ca, Mg, Fe, Zn, and Cu increased while Pb, Cr, and Mn value showed no signifcant change with compost application. Field application of compost improved onion shoot numbers, shoot girth, and shoot length. Further, signifcant shoot weight and bulb weight were also obtained after compost treatment.

After compost amendment signifcant improvement in soil fertility and onion yield was obtained. This can be recommended for small scale farmer’s food security improvement and combined with agro industrial wastes management.

Soil fertility management requires a precise assessment of nutrient release from organic amendments to decide the rates and frequency of application.

Time-dependent release of some macro- and micro-nutrients from farmyard manure, mushroom compost, poultry manure, vermi-compost, biogas slurry and biochar of Lantana sp. was studied during 120 days incubation through entrapment of released nutrients on ion exchange resins.

Highest total concentration of K, Ca, Mg and S was in farmyard manure, Fe and Mn in mushroom compost, P, Zn and Cu in biogas slurry and B in biochar. Farmyard manure had the highest C:N ratio (34.2), while other organic amendment had C:N ratio<20. The highest release of P, Ca, Mg, Zn and Cu was recorded from biogas slurry, of K and S from farmyard manure, of B from poultry manure and of Fe and Mn from mushroom compost. Mean percentage of total nutrient released was 30.5% P, 71.8% K, 23.1% Ca, 24.4% Mg, 29.3% S, 47.2% Zn, 22.9% Cu, 38.6% Fe, 46.6% Mn, and 70.9% B. Nutrient release from diferent organic amendments conformed to zero-order kinetics. The percent of total released nutrient, release kinetic constants and half-life of nutrients was related to the properties of organic amendments.

Based on the released amount of nutrients from diferent organic amendments, the best source seemed to be farmyard manure for S and K, mushroom compost for Fe and Mn, biogas slurry for P, Ca, Mg, Zn and Cu and poultry manure for B.

Huge quantity of paper mill wastes are dumped at the outskirt of factory as unwanted materials. Vermicomposting is an eco-friendly technique for benefcial conversion of diferent biodegradable/organic wastes into useful organic manure utilizing earthworms. Solid wastes generated in paper mills contain appreciable quantity of organic matter. Attempt was made for bio-conversion of Emami paper mill wastes with diferent numbers of Eisenia fetida (5–30 earthworms/2 kg substrate) for studying its infuence on vermi-conversing time and quality of prepared vermicompost.

Vermicomposting was carried out in trays following heap method and quality of fnal product was determined following both chemical analysis and bioassay on wheat seedlings.

Application of more earthworms up to 20 numbers per 2 kg substrate made bio-conversion quicker but further addition of earthworm, however, delayed the process as some earthworms came out of beds and died probably due to competition for food among earthworms inside beds. Ten earthworms per kg paper mill wastes–saw dust–cow dung mixture (1:0.5:0.5 weight wise) was found as optimum earthworm population for preparing quality vermicompost having more major and secondary plant nutrients. Bioassay of this manure on wheat seedlings also confrmed the analytical fndings.

It is confrmed that earthworm population in vermibed played vital role in faster decomposition of paper mill wastes and releasing of more nutrients, which ultimately helped in better growth of wheat seedlings. Successful demonstration of vermicomposting technique will encourage local farmers for benefcial utilization of paper mill wastes in their agriculture.

Recycling of nutrients from human excreta may offer an opportunity for smallholder farms to improve crop nutrition and soil fertility. However, when applying human urine as fertilizer, it may load natural and synthetic estrogens into the environment. To avoid pollution by endocrine disruptors, treatment methods before field application must be implemented. The present study thus aims to evaluate the reduction in estrogenic activity in human urine during the storage period before urine is applied to the field.

This study evaluated the estrogenic activity in diluted urine (DU) exposed to simulated sunlight (280–700 nm) and under dark conditions for 75 days. Estrogenic activity was analyzed using the recombinant yeast estrogen screen assay. Concentrations of total nitrogen (Ntot), ammonium–N (NH4–N) and dissolved organic carbon were measured, as well as electrical conductivity and pH. Correlation of factors to the reduction of the estrogenic activity was also evaluated.

Decay of estrogenicity occurred in both treatments, though it was faster in DU exposed to light (k = 0.07 day−1) as compared to DU under darkness (k = 0.05 day−1). Exposure of DU to a direct light source enhances decay of estrogenicity, however, losses of available N can be significant.

While reduction of estrogenic activity in DU stored under dark conditions takes longer, it is easy and does not require expensive equipment, energy sources or profound chemical expertise. Therefore, we suggest storage of DU under dark conditions as the best option for small-scale farmers and households in rural areas of developing countries.

Due to the pressures of conforming to environmental quality standards and the increased costs of mineral fertilizer importation, there is growing interest in the use of organic residues as fertilizers. To test the hypothesis that indicates the quantity of animal manure (AM) depends on the phosphorus (P) needs of the crops, an experiment was run using three organic animal manures (chicken—CM, turkey—TM, and cow manure—CoM), enriched with limestone, gypsum, and phosphorus.

A greenhouse experiment was run using AM incorporated in a clayey soil, at a rate that equates to the P needs of Brachiaria sp. Contents of phosphorus, potassium (K+), calcium (Ca+2), magnesium (Mg+2), sodium (Na+), organic matter (OM), and values of pH and cation exchange capacity (CEC) were monitored during 120 days. Plants were collected to determine the dry matter.

Application of enriched AM increased the contents of Ca, Mg, and K over time, while P and OM presented a decrease. Soil fertilized with CoM resulted in the greatest contents of P and OM, while soil with TM presented the highest production of dry matter with the lowest contents of P in soil. There was an increase in Na content in soil with the application of AM.

Fertilization with AM presents the potential to supply P, Ca, Mg and K for plants. Enriched CoM appears to be the most viable option to improve the phosphorus and organic matter in soil because of high C/N. However, farmers may need to pay attention to the quantity of Na.

This study aimed to assess the impact of two biochars applied at the rate of 15 t ha−1 on physico-chemical parameters of an oxisol in Cameroon.

The biochars were made from slow pyrolysis (~ 300 °C, 4 h) of eucalyptus tree bark and corncobs and then incorporated into the top 15 cm of the soil with or without straw. The soil tillage mode was either flat plots or furrows and ridges. Soil porosity, bulk density, saturated hydraulic conductivity, available water content, pH, nitrogen, potassium, phosphorus, cation exchange capacity and electrical conductivity were analysed before biochar application, then 6 and 12 months after.

None of the measured soil physical parameters were affected by the presence or type of biochar. The total porosity was lower during the second production period compared to the first, while available water content and van Genuchten parameters increased during the second production period. No significant difference was observed between soil nitrogen, phosphorus, potassium, cation exchange capacity and electrical conductivity of control and treated plots.

We recommend that straw be pyrolysed and the resulting biochar incorporated into soil instead of burying straw (as is actually done in furrow and ridges tillage mode).

The research was performed to assess the effect of vermicompost and tuber size on the storage behavior of potato during the ambient condition.

The research was consisted of two factors, i.e., factor A: vermicompost level (Vm-4): Vm1: 0 t ha−1 (control), Vm2: 3 t ha−1, Vm3: 6 t ha−1, and Vm4: 9 t ha−1; factor B: tuber size (T-5): T1: 5–10 g, T2: 10–20 g, T3: 20–30 g, T4: 30–40 g, and T5: > 40 g. The research was conducted in a split-plot design where vermicompost levels were assigned to the main plots and tuber sizes to the subplots.

Vermicompost had a significant effect on most of the processing quality contributing parameters of potato. Processing quality parameters increased with increasing vermicompost level irrespective of tuber size. Among the 20 treatment combinations, vermicompost @ 9 t ha−1 with tuber size > 40 g exhibited the highest starch (23.81 mg g−1 FW), antioxidant (478.84 Trolox µMol 100 g−1 FW), polyphenol (96.133 GA mg 100 g−1 FW), and the lowest reducing sugar (0.1020 mg g−1 FW). In respect of ambient storage condition, starch decreased with increasing storage time; reducing sugar gradually increased with increasing storage time up to 40 days after storage (DAS) and after that slightly decreased and finally, potato became non-suitable for both table and processing purpose; antioxidant and polyphenol slightly increased up to 20 DAS and after that gradually decreased with increasing storage time.

Potato growers may use vermicompost for increasing and improving processing quality of potato.

Recovery of nutrients from water using duckweed and their reuse has significance in closing the loop on nutrient transfer from anthropogenic sources. This study investigated the effect of rate of application and pre-incubation period of duckweed on biomass and nutrient uptake of Swiss chard (Fordhook giant).

Two glasshouse experiments were laid out in randomized complete block designs with three replicates. In the first experiment, Swiss chard was grown on two soils (ferralsol and regosol) amended with Wolffia arrhiza biomass at 0, 50, 100 and 200% of the recommended nitrogen rate. In the second experiment, the same vegetable was grown on the ferralsol amended with W. arrhiza and Lemna minor at recommended nitrogen rate, with pre-incubation periods of 0, 14 and 28 days.

Application of W. arrhiza biomass increased Swiss chard dry matter by 23–45% compared to the negative control. The positive control (urea at 100 kg N ha−1 rate) had highest Swiss chard biomass. Higher rates than 100 kg N ha−1 had no added benefit on dry matter accumulation and nitrogen uptake of Swiss chard. Pre-incubation of duckweed for 28 days improved nutrient uptake, resulting in higher dry matter than shorter periods. The Swiss chard dry matter after pre-incubation for 28 days was similar to that from urea application.

Findings from this study suggest that duckweed is a resource with beneficial use for nutrient supply to vegetables, especially when appropriate rates are used with pre-incubation.

Despite durum wheat accounts for only 5% of the global wheat production, it represents an economically important species, as a basic food and primary source of daily caloric intake in the Mediterranean basin area. By-products of agricultural processing, such as pomace, can be used to increase soil fertility, as they are indeed a source of important nutrients useful for crop growth.

The present research was carried out on durum wheat, as part of a long-term experiment. The study aimed at assessing the effects of mineral and organic fertilization with the use of wet olive pomace on a 3-year trial with crops grown in succession (fava beans—wheat—spelt). A split-plot experimental design with three replicates was used. The cultivars (Aureo and Vespucci) were assigned to the main plots and the seven fertilization treatments to the sub-plots.

Our result showed that supplying wet olive pomace as soil improver was not sufficient to significantly improve soil fertility compared to the unfertilized control. However, when 60 kg ha−1 of nitrogen was supplied in coverage before tillering, in addition to 70 Mg ha−1 of wet olive pomace yield an increase of 66% in Aureo cv and of 222% in Vespucci cv, in comparison to the unfertilized crop.

The best management of fertilizers, associated with the use of more nitrogen-use-efficient genotypes, is essential for the development of a sustainable agriculture.

Aquaponics combine aquaculture with crop production in a mutual system. In this experiment, the growth of Amaranthus in aquaponics with tilapia fish was investigated.

500-liter water tanks containing tilapia fish at four initial stocking densities of 100, 150, 200, and 250 fish/m3 were used in triplicates, with a view to evaluate vegetable yields as influenced by fish biomass to water ratio. 1 g of Amaranthus seeds were sown in a 1 m2 planting trough, which contained gravel with a top layer of sandy soil. The pots were flooded with water from fish holdings by an aquarium pump.

The germination rate of Amaranthus was not significantly different across the experimental setup (P > 0.05). The growth rate of Amaranthus was significantly higher with increasing fish density (P < 0.05). The average lowest and highest of shoots dry biomass yield recorded were 0.36 and 1.95 g/plant at 8 weeks after of sowing, and this corresponds to fish stocking densities of 100 and 250 fish/m3, respectively. A high positive correlation was found between the shoot dry biomass of Amaranthus and fish stocking density. The survival of tilapia fingerlings was not significant different, while the production levels were 5.62, 4.77, 4.57, and 4.00 kg/m2 in 100, 150, 200, and 250 fish/m3.

The growth of Amaranthus in this experiment demonstrated that the plant could effectively utilize the nitrogenous waste from fish tanks for biomass production, even at a higher concentration, while considerations for moderate fish density are only for fish health.

Amylase being one of the most important industrial enzymes requires large-scale production. When producing an enzyme, high productivity, high purity and low production costs need to be considered. This study focuses on comparing various agro-industrial waste substrates, for production of alpha-amylase using Bacillus amyloliquefaciens. Moreover, it studies the stability and activity of amylase–gold nanoparticles composite.

This study is divided into two parts, in the first part various agro-industrial waste substrates, such as wheat bran, rice bran and potato peel were used to produce alpha-amylase using solid-state fermentation (SSF). The production of the enzyme was quantified and compared in specific enzyme activity units. In the second part, change in the stability and activity of amylase in enzyme–gold nanoparticles (AuNPs) composite has been discussed.

Highest enzyme production was observed in wheat bran and potato peel substrate with specific enzyme activity of almost 1.2 U/ug and 1.1 U/ug. Among combination substrates, wheat bran with potato peel showed a high enzyme production of 1.3 U/ug. On the other hand, the optimum temperature for amylase activity shifted to 55 °C in the composite compared to 37 °C for free enzyme.

Comparison of specific enzyme activity of extracts from various substrates showed that wheat bran alone, and in combination with potato peel, produces active and pure amylases. To stress on various catalytic activities of alpha-amylase, the capability of the enzyme to synthesize gold nanoparticles and the effect of conjugation of the nanoparticle on its optimum catalytic activity are also discussed in this paper.

Rice-mill wastes are generated in large amounts in Ishiagu, Ebonyi State, Nigeria. These wastes can potentially be utilized for rice production and in improving soil attributes. This study evaluated the effects of rice-mill wastes on soil chemical properties and rice yield in sawah rice management.

A sawah rice field in an inland valley of southeastern Nigeria was used in 2014 and 2015 cropping seasons for the study. Sawah refers to an Indo-Malaysian term for rice paddy. It involves the manipulation of some soil physical properties in form of ecological engineering works, by bunding, puddling and leveling of lowland rice field for water control and management. Two rice-mill wastes [rice husk ash (RHA) and rice husk dust (RHD) applied at 0, 2.5, 5, 7.5, 10 and 12.5 t ha−1] and the control were built into a split-plot in a randomized complete block design with three replications.

Bio-waste application had significant (p < 0.05) improved effects on the soil organic carbon, available P, soil available Si and total N compared with the unamended (control) treatment. There was significant (p < 0.05) increase in rice grain yield from 5.05 to 5.80 t ha−1 (for RHA) and 6.17–6.96 t/ha (for RHD) compared with 2.35–2.8 t ha−1 (control treatment) in both cropping seasons.

RHD and RHA treatments had significantly higher rice grain yield compared with the control treatment. Overall, rice grain yield was higher under RHD treatment compared with RHA treatment. This result demonstrated that RHA and RHD are potential agricultural resource for rice production in the study area.

Source segregation of food waste is one of the major challenges that inhibit food waste recycling around the world. Therefore, the purpose of this study was to investigate the role of the local authority to implement regulations and encourage an increase in the source separation of food waste within both commercial premises and households, and identifying any gaps that exist in public awareness.

This study was conducted by the Cork County Council in 568 commercial premises and 1362 houses in County Cork, Ireland. This study also included investigations of public and private civic amenity sites and waste collectors that collect kerb side waste located within the region. The interviewee’s responses were documented and a database has been prepared and analysed.

Integrated strategy is crucial to roll out food waste bin within a community for successful implementation of source segregation of food waste. This strategy should involve a dedicated team from the local authority who continue to visit, monitor and co-ordinate the activities of local authorities, waste collectors, civic amenity sites and public to implement and enforce the food waste regulations. In addition to organising appropriate infrastructure for recycling of food waste, continuous awareness raising through education, leaflets and local and national media is also crucial.

The role of local authorities should include facilitating the development of appropriate facilities such as composting, anaerobic digestion within communities and to encourage communities to take ownership of these facilities and reuse the resultant material within the local area.

This study aimed to design a biogas digester that works thermophilically and mesophilically and tested its performance to produce biogas and digestate.

This study used some experimental methods, which consists of: (1) design and construction process of the digester which can facilitate the thermophilic process as a pretreatment of the feedstock and the anaerobic digestion process of the substrate; (2) determination of the quantity of biogas, liquid digestate, and compost; and (3) testing digestate quality as a liquid organic fertilizer for Ipomoea reptans.

The built biogas digester was able to accommodate thermophilic digestion that runs intensely in the pretreatment tank, where the complex organic compounds, namely cellulose and hemicellulose, decomposed intensively, so that it becomes a suitable substrate. As raw material, every 4 kg of banana waste, can produce biogas, digestate and dry compost of 10,200 cm3 (highest yield), 5900 mL, and 1420 g, respectively. The highest Ipomoea reptans growth was achieved by digestate treatment from banana waste.

Thermophilic pretreatment could shorten the processing time to 3 days. Digestate treatment as a liquid organic fertilizer is able to provide a better supply of nutrients for plants.

Utilization of food waste as composting materials offers a sustainable solution to manage waste and reduce reliance on fertilizers.

This study is focused on the efficiency of food waste compost and the effect of the addition of magnetite (Fe3O4) nanoparticles on the growth and heavy metals uptake by roselle (Hibiscus sabdariffa) for the cultivation period of 127 days. Five different treatments were applied, namely soil (S), food waste compost (F), a mixture of soil and Fe3O4 (SM), a mixture of soil and food waste compost (SF), and a mixture of soil, food waste compost, and Fe3O4 (SFM).

After 127 days of cultivation, the plant height averaged at 803 mm with 26 leaves produced across all treatments. Total leaf area, fruit production, and biomass yield were different (P < 0.05) among the treatments. Roselle crops grown under soil and food waste (SF) media produced the highest yield (12.15 g/plant), the most number of fruits (11 fruits/plant), and the highest leaf area (1200 cm2/plant). The accumulation of heavy metals in plant tissues was lower than the toxicity levels. There was no difference in the heavy metal content in all growing media, except for Ni, Mn, and Pb. Roselle crops applied with Fe3O4 showed no difference (P > 0.05) from its control (without Fe3O4) in relation to growth performance.

The findings of this study showed that food waste can be applied in composting to promote plant growth. Therefore, it can be considered as a substitute for chemical fertilizers. Meanwhile, the application of Fe3O4 appeared to be experimental-condition dependent.

Purpose This study aims to evaluate the potential negative effects of rice husk as a source of fertilizer on plant growth. Methods Growth tests were conducted on komatsuna (Brassica rapa var. perviridis) using three types of experiment. A pot experiment was conducted to compare different fertilizers on an individual basis. A second pot experiment was conducted to compare different mixtures of fertilizers. Finally, a field experiment was performed to determine the effects of the application of different quantities of silica. Results The results showed that komatsuna grew better with the application of silica mixed with fertilizer, and that there was an optimal quantity of silica to be used, when used on its own. It was found that, in all cases, the silica in the rice husk ash did not have any measurable negative effects on the growth of the komatsuna. Conclusions We, therefore, conclude that rice husk silica can undoubtedly be used for plant cultivation.

During the apple processing procedures, a large amount of apple pomace is generated which is contains peel, core, seed, calyx, stem, and soft issue. The polyphenolic compounds in apple pomace are strong antioxidants that are able to counterbalance the free radicals; also, it is a rich source of many nutrients such as carbohydrates, minerals, fiber except protein. The experiment was conducted to investigate the effect of different levels of dried apple pomace in broilers diet.

The incremental levels of dried apple pomace (4, 8, 12, 16 and 20%) with and without enzyme were used in broilers diet (8 dietary treatments). The growth performance, immune response, gut development, antioxidant capacity (TAC) and blood biochemical parameters were evaluated.

The lowest daily weight gain, body weight and poorest feed conversion ratio was obtained by F treatment (P < 0.05), enzyme inclusion along with dried apple pomace had positive effect on growth performance. The antibody titter against Newcastle, Influenza and SRBC was increased by C, H, G and H treatments, respectively (P < 0.05). Antibody titer against NDV, IDV, and SRBC by 4, 8, 12 and TAC by 12, 16 and 20% of dried apple pomace significantly increased. The villous height by 4, 8, 12 and crypt depth by 12, 16 and 20% dried apple pomace significantly and insignificantly decreased, respectively.

The results suggested that the incremental levels of dried apple pomace deteriorate growth performance, modified antibody titer production, total antioxidant capacity and blood parameters of broilers.

Present work aims at studying the influence of active (using external aerator) and passive (natural) aeration on composting of household biodegradable wastes.

To study the suitability of these reactors to household conditions, continuous loading was carried out for a period of 60 days. Both the reactors were loaded with cooked as well as raw vegetable and fruit waste. Physico-chemical parameters such as temperature, pH, C/N ratio, moisture content, total organic content, Total Kjeldahl Nitrogen and seed-germination parameters such as Germination Index (GI) and Root Length Index (RLI) of the mulch were analyzed at different stages of the composting process.

Results confirmed that, although both types of aeration seem to have performed well under continuous loading, the maturation period required for actively aerated reactor was 37.30% lesser than that of naturally aerated reactor.

Active aeration found to be more suitable to household conditions as odor and fly nuisance was relatively less.

Mulching is a practice recommended for soil moisture conservation in potato. The wheat straw and rice straw obtained as major crop residues were used as mulching materials to compare their effectiveness for soil moisture retention in potato crop.

The field experiments were conducted in a randomized complete block design replicated thrice with three treatments viz. plots incorporated with wheat straw mulch, rice straw mulch at the rate of 10 tonnes per hectare each and no mulch serving as control. The soil moisture was determined using a soil moisture probe and data were recorded daily at 10 cm, 20 cm and 30 cm soil depths. The Field Emission Scanning Electron Microscopy was used to investigate moisture retention characteristics of the mulch materials.

Soil moisture retention varied as wheat straw mulch > rice straw mulch > no mulch at 10 cm, 20 cm and 30 cm soil depths, respectively. Highest moisture retention in wheat straw mulch at 10 cm depth is attributed to better moisture absorption ability of wheat straw in comparison to rice straw. Field Emission Scanning Electron Microscope images indicated the presence of smaller sized micro tubes in wheat straw than rice straw, which resulted in more water retention, thereby substantiating the findings of the study.

Wheat straw mulch is more effective than rice straw mulch for shallow rooted crops like potato, due to better moisture absorption and retention in upper soil layer.

The effect of different initial carbon to nitrogen (C/N) ratios on the prevalence of Salmonella spp., fecal coliforms and helminth eggs over composts produced from several mixtures of maize straw (S) and dairy manure (M) was investigated.

Four C/N ratios (21, 22, 27, and 38) were evaluated, including one with manure only (C/N 21). The composting process was performed under field conditions in northern Mexico.

The process lasted 51 days; Salmonella spp. was reduced 1–2 log (> 94%) in most treatments, except for the C/N ratio of 27 which achieved < 1 log reduction (about 35%). Fecal coliforms elimination was 3–4 log (> 99%) in all treatments while helminth eggs achieved < 1 log (72–87%, depending on treatment). In this study, the mixture with initial C/N ratio of 22 (25% S + 75% M), which had the lowest amount of straw, resulted in the highest elimination of Salmonella spp., fecal coliforms, and helminth eggs. This mix complied with current Mexican sanitary regulations for compost use. The composts produced from the other C/N ratios complied only with the limits for one or two of the microorganisms that were analyzed.

The initial C/N ratios in compost from straw and manure influences microbial reduction. The final C/N of the mixes ranged from 14 to 16, indicative of stable compost. Compared to fecal coliforms, Salmonella spp. and helminth eggs were more resilient.

An 8-week incubation study was conducted to monitor soil inorganic nitrogen (N), dissolved organic carbon (DOC), greenhouse gases (GHG) [CO2, N2O and CH4] and cumulative global warming potential (GWP) in dryland soil.

Soil was amended with variable rates of compost (zero, 15, 30 and 45 dry Mg ha−1) and soil moistures [5% (dry), 7% (normal) and 14% (wet) water filled pore space (WFPS)] and experienced biweekly temperature transitions from 5 °C (late winter) to 10 °C (early spring) to 15 °C (late spring) to 25 °C (early summer).

The addition of 30 and 45 Mg ha−1 compost enhanced N mineralization with 13% more soil inorganic N (7.49 and 7.72 µg Ng−1 day−1, respectively) during early summer compared with lower compost rates. Normal and wet soils had 35% more DOC in the late spring (an average of 34 µg g−1 day−1) compared to the dry WFPS, but transitioning from late spring to early summer, DOC at all soil WFPS levels increased. Highest rates of compost were not significant sources of GHG with normal soil WFPS, compared with lower compost rates. Carbon dioxide emissions increased by 59 and 15%, respectively, as soil WFPS increased from dry to normal and normal to wet. Soils with normal WFPS were the most effective CH4 sink.

One-time application of high compost rates to dryland soils leads to enhanced N and C mineralization under normal soil moisture and warmer temperature of the summer but will not pose significant global warming dangers to the environment through GHG emissions since soils are rarely wet.

Municipal sewage sludge generated from three operational wastewater treatment plants, located in the Bekaa valley of Lebanon, was assessed for its potential use as agricultural soil amendment.

Sludge samples were taken from three treatment plants located in the villages of Iaat, Ablah and Joub Jannine during the summer season of 2018, from June to September, on a monthly basis. The evaluation was based on characterizing the physicochemical parameters such as the metal content, the pathogenic microorganisms (Salmonella, E.Coli, Staphylococcus aureus, Helminth eggs, Ascaris, Acinetobacter) and the phytotoxicity–stability indicators of the sludge samples.

The obtained results were compared to the Lebanese guidelines for sludge reuse in agriculture. For the physicochemical analysis, all the samples showed a possibility to be used in agriculture due to the high content of minerals and organic matter. Considering the metal content of sludge, Iaat and Ablah sludge were classified as Class A according to the Lebanese guidelines; however, sludge from Joub Janine was classified as B due to its high content of zinc that exceeded the limit of 700 ppm. Helminth eggs and Salmonella were absent in the sludge samples. Pathogenic organisms, mainly E. coli, were detected in Iaat dry sludge, Staphylococcus aureus was present in Joub Jannine sludge and Acinetobacter in Ablah station (> 100 CFU/100 g).

It is recommended to submit the sludge which did not meet the required criteria, for further treatments, particularly the composting process to reduce the metal content and pathogenic microorganisms for a safer reuse in agriculture.

Green waste (GW) composting is of increasing importance to the waste management industry in addition being a useful agricultural product that is rich in nutrient and organic matter (OM). The combination of aerated static windrow with GORE(R) cover membrane and an air-floor aeration system is a relatively new industrial-scale composting technology that has not been previously explored. Therefore, the aim of this research study was to evaluate the effectiveness of composting GW using this new technology.

The composting process was monitored through changes in the physico-chemical properties, E4/6, and fourier transform infrared (FTIR) spectra.

Disinfection requirements were met by holding composting temperature steady in the thermophilic range for 24 days. The technology greatly improved composting conditions, and final compost product in terms of temperature, pH, electrical conductivity (EC), C/N ratio, OM degradation, nitrogen transformation, humification, and cation exchange capacity (CEC). The FTIR spectra revealed that there was enrichment of aromatic compounds and reduction in aliphatic structures and easily assimilated peptide components by microorganisms, indicating the humification degree increased, the final compost stabilized, and confirming the efficiency of composting. Consequently, the new technology produced a mature compost in only 30 days compared with the standard period of 90–270 days for traditional composting.

Notably, the new technology may be a sustainable alternative for GW management that converts waste into compost and could be beneficial for agricultural uses.

Rice husk is one of the most widely available agricultural wastes in many rice producing countries of the world. Here, we evaluated carrot production under different rice husk-amended media aimed at providing alternative use for rice husk.

The experimental design was 2 × 5 × 4 factorial in completely randomized design with six replications. Factor A consist of two production environments—high tunnel and open field while factor B was five growth media—5:0:0, 4:0:1, 3:1:1, 2:2:1 and 1:3:1 (topsoil:rice husk:poultry manure). Factor C was four carrot varieties; ‘Touchon’, ‘Amazonia’, ‘Carrot New Kuroda’ and ‘Touchon Mega’. Data were collected on seedling emergence and yield parameters. The analysed means were separated using FLSD(0.05).

The biomass yield from plants grown in high tunnel was significantly higher than plants in the open field. Highest root weight, wet and dry biomass yield were obtained from medium 4:0:1 followed by 3:1:1. Harvest index ranged from 32.3% in medium 1:3:1 to 62% in 3:1:1. Days to seedling emergence among varieties ranged from 8.5 to 11.3. ‘Amazonia’ variety produced the highest root weight, wet and dry biomass yield and was followed by ‘Touchon Mega’.

Carrot seedling emergence and yield differed in rice husk-amended media under high tunnel and open field environments. ‘Amazonia’ variety grown in media 4:0:1 or 3:1:1 gave the best yield. Inclusion of rice husk in media formulation beyond an optimum rate resulted in yield reduction in carrot. Carrot is sensitive to the physio-chemical properties of its growth medium.

Biochar addition to soil is immensely beneficial for increasing plant productivity and C sequestration, attenuating nutrient leaching loss, counteracting heavy metal contamination and organic waste triggered environmental pollution. To understand the sustainable benefits of biochar, two pot experiments were conducted under net house condition in Khulna University, Bangladesh.

Biochar was prepared from banana peel waste through slow pyrolysis process under limited oxygen condition. Three lower rates (1, 2 and 3%) of banana peel biochar (BPB) were added with agricultural soil along with control with three replications for each. After incorporation of BPB into soil, pots were kept under field condition for 7 days and then the seeds of Ipomoea aquatica were sown. Plants were harvested after 42 days from seeds sowing and plant height, leaf number, fresh weight, and dry weight were measured. Another pot experiment was also conducted under sand medium to test the BPB as K-rich soil amendment where K was applied from two different sources (KCl and BPB) along with control. Seeds of Cucurbita moschata were sown and 40 days after seed sowing, K deficiency was observed in control treatments.

Banana peel biochar was found to be rich in K content. Plant productivity and above-ground biomass were reduced in 1% BPB treatments, but increased in 2 and 3% BPB treatments as compared to control but statistically insignificant (p < 0.05). In case of second experiment, K deficiency symptoms were observed in 40 days aged Cucurbita moschata seedlings under control treatments, whereas no K deficiency symptom was noticed in plants grown under K supplied from both KCl and BPB. Moreover, the plant grown with BPB was found healthy, stronger and greener in appearance.

This positive influence of BPB on plant growth suggests the alternative way to overcome the use of chemical fertilizer and effective way of utilization of agricultural wastes through recycling.

Litter decomposition is a biological process resulting from enzymatic activities of microorganisms and influenced in a variety of ways by activities of termites in semi-arid regions. We presented a general model of the decomposition process from litter to carbon sequestration and nitrogen. We aimed at building a termite population growth model which could deal with one substrate.

Our model divides the decomposition/growth process at the population level. We put these changes into equations using an analogy with chemical reactions at equilibrium.

Our findings provide evidence that activities of termites can promote the significant activity of microbial decomposers and increase degradation rates of soil organic matter (SOM). Also, termite activity was probably an additional contributor to the difference between fungus-comb chamber and soil environment, in which the fungus-comb compartment was positively related to carbon and nutrients release. According to the developed, observed differences in decomposition rate, changes were strongly affected by the termite communities’ activities in the two types of compartment.

This functional distinction highlights the importance of termites’ activities on microbial activities stimulation through their development featuring their impacts on soil nutrient cycling.

This study sought to investigate the effects of organic amendments on the degradation of hydrocarbons and vegetative properties of Zea mays grown in crude oil-contaminated wetland soils of the Niger Delta, Nigeria.

Two soil types were investigated, namely, fadama soil (oxisol) and swamp forest soil (utisol). For each soil type, 48 treatment cells and 1 control containing 1 kg of soil each were spiked with crude oil at concentrations ranging from 50 to 200 g kg−1, representing 5–20% (m/m) contamination levels, respectively. Then, 5 days after the contamination, the soils were amended with cow dung (CD), poultry waste (PW), and palm oil waste (POW). The ratios of soil to organic amendments used were 1:1 and 2:1. The soils were tilled and irrigated regularly, and monitored for a total period of 112 days. The same conditions were used to investigate the vegetative properties of Z. mays in these oil-contaminated soils with organic amendments.

The total organic carbon (TOC) and pH increased significantly within the first 2 weeks after crude oil contamination; thereafter, the pH of the soil decreased significantly over incubation time, while there was steady increase in TOC with incubation time. The percentage nitrogen and total petroleum hydrocarbons (TPH) decreased significantly. The utisol soil showed better plant performance, despite the lower hydrocarbon degradation rate.

The organic amendments showed a TPH degradation trend that followed the order: PW > CD > POW. They also improved the seed emergence of Zea mays.

Reuse of treated wastewater (TWW) for irrigation can be an effective strategy in Morocco to overcome the pressure on freshwater resources. The M’zar wastewater plant is based on percolation infiltration treatment, allowing the purification of the wastewater of Agadir, and with its UV disinfection system, it is now possible to reuse this water for irrigation. In this sense, the aim of our study is to evaluate the microbiological and physicochemical quality of the treated wastewater of this station, used for irrigation of a Golf course as well as to determine its impact on grass and soil.

A monitoring of TWW quality was carried out monthly on the level of the Ocean’s Golf on water samples, grass and soil. This monitoring is related to the physicochemical (pH, temperature, conductivity, STD, COD, and BOD5) and bacteriological characteristics by counting the indicators of faecal contamination, faecal coliforms (FC), faecal streptococci (FS), Salmonella and Vibrios as well as sulphito-reducers spores (SRS).

The results of microbiological analysis in the three compartments confirm the presence of various organisms such as FC, FS, and SRS in a very significant number with no load in Salmonella and Vibrios during our study period. For physicochemical analyses, we observed that only the conductivity showed fairly a high value of 6.38 dS/m.

The obtained physicochemical and bacteriological results revealed that the treated wastewater with the M’zar plant complies with national and international standards.

Novel protein sources are urgently needed to meet the increasing protein demand of a continuously growing world population. This study is focused on the production of protein rich mushroom mycelia on industrial side streams.

Submerged propagation of mushrooms was carried out in shake flasks which contained agro-industrial side streams as the sole carbon source. The biomass obtained was analyzed for its crude protein, ash and fat content as well as for its fatty acid and amino acid profiles. Vitamin D2 production from ergosterol in the biomass was induced by UV-B irradiation and determined by HPLC–DAD. The share of fungal mycelium in the total biomass was determined by extraction and quantitation of ergosterol. Additionally, water and oil binding capacity (WBC and OBC) were evaluated.

A screening of basidiomycetes grown on agro-industrial side streams indicated a fast growth of Pleurotus sapidus on apple pomace. After 4 days of cultivation, the biomass obtained from this mushroom–substrate combination contained 21% true protein in dry matter. In addition to proteins, the amounts of lipids (4%), ash (2%) and carbohydrates (74%) were quantitated. The dominating fatty and amino acids of Pleurotus sapidus grown on apple pomace were linoleic acid and glutamic acid/glutamine, respectively. Concentrations of up to 115 µg (g dry matter)−1 vitamin D2 were formed from ergosterol by UV-B irradiation. Ergosterol was used as a biomarker to monitor the amount of fungal content.

The nutritional value of agro-industrial side streams such as apple pomace can be upcycled by biotransformation with basidiomycetes.

Agricultural chemicals either used as nutrient inputs for soil fertility or pesticides are creating physicochemical and biological deterioration of the soils and disturbing the agro-ecosystems worldwide. Alarming concerns towards integrated agroecology demand for renewed interest in low-external input-based farming practices. These practices comprise strengthening of soil biological properties, recycling of inherent soil minerals and reuse of agricultural residual wastes.

We described approaches for the bioconversion of agricultural residual wastes into value-added compost. The process involves conversion of residual waste into raw compost followed by its fortification with beneficial decomposer microorganisms to produce quality fortified compost product. Finally, incubation of fortified compost with single or consortia of beneficial microorganisms like N-fixers, P-solubilizers or K-mobilizers and biocontrol agents further enriches compost to produce bioorganic products.

Bioconversion of agricultural wastes into compost using potential decomposer microorganisms and fortification of decomposed organic matter with beneficial bacterial and fungal species is of immense importance. Additional enrichment of compost with botanicals, humic acid, amino acids, mineral nutrients, phytohormones etc. may also add value to the bioinput products.

In an integrated way, on-farm production of raw compost using different agricultural residual wastes and its further fortification with bioorganic farm inputs can help farmers produce value-added compost products for direct application in the crop production. Adoption of microbial bioconversion technologies and their field applications may become eco-enterprising for the rural resource-poor farming communities for enhancing their livelihood along with improving farm productivity and soil health.

Chicken feather was thrown into the environments, which causes health hazards and environmental pollution. It contains large number of proteins which can be converted into organic fertilizer to reduce the pollution load. These will help to minimize the protein needs and maintain low cost for utilization as raw material for manure production.

Chicken feather waste was subjected to composting by mixing it with cow dung and agricultural waste. Four different composts were prepared for composting of the chicken feather waste: E1, E2, E3, and E4, along with a control [cow dung (CW) + agricultural waste (AG)]. The major and minor nutrient contents of the compost were analyzed on the 90th day. The prepared compost was applied to Solanum lycopersicum plants; fruits pigments (lycopene, β-carotene, and chlorophyll) were evaluated.

Chicken feather compost has high nutrient level organic carbon (1.83%), nitrogen (7.33%), potassium (4.40%), sulphur (19.69 ppm), zinc (4.96 ppm), boron (0.59 ppm), and iron (6.62 ppm) except phosphorus (0.26%) in the control. Results revealed highest lycopene in E4 (0.5881 mg/100 ml) and β-carotene in E1 (0.2699 mg/100 ml) when compared with the control value lycopene (0.4602 mg/100 ml) and β-carotene (0.1341 mg/100 ml). A positive correlation has been established between lycopene/β-carotene and negative correlation have been existing chlorophyll content vs lycopene/β-carotene.

Chicken feather can be eco-friendly when converted into compost which in turn enriches the quality of tomato fruits (lycopene and β-carotene).

Rice straw which predominantly contains cellulose, hemicellulose and lignin, can be converted into value-added product such as bio-compost. The present study was planned to carry out rice straw degradation, added with agricultural residues like rice bran and fruit waste in different combinations, with standard fungal culture of Trichodermaharzianum MTCC 8230.

Rice straw added with fruit waste and rice bran was moistened with sterilized water in five different proportions. The experimental trays were inoculated with spore suspension (1 × 108 spores/ml) of T. harzanium. The trays were observed for change in pH, appearance and chemical fibres (acid detergent fibre, neutral detergent fibre, and acid detergent lignin).

A continuous increase in bulk density accompanied with a decrease in volume was observed in all the experimental trays including the control. There was an initial increase in pH from 7 to 9 which stabilized to 8 after 12 days of incubation. The crystalline structure of rice straw was transformed into amorphous one in a time frame of 28 days, with a significant decrease in lignin from 20–25% to 13–15% and an increase in crude protein from 5–17%.

The crystalline rice straw was reduced to a brown crumpled and compact value-added composted biofertlizer with a high carbon and crude protein content.

The shell of cocoa beans is one of the cocoa industry byproducts that currently still become waste. Through this research, utilization of cocoa bean shell for producing alkalized fiber powder was observed. The aim of the study is producing fiber powder from the shell of cocoa beans.

The shell of cocoa beans was obtained from the chocolate industry and directly used without any pretreatment. The shell of cocoa beans was alkalized to adjust the pH and remove the possible heavy metal. At the end of the alkalization process, the solid material was measured by atomic absorption spectroscopy (AAS). Later, the solid material was crushed into 30–200 mesh. The possibility for this powder to substitute other fiber powders (oat and whole wheat) was tested by texture profile analysis (TPA) and panelists test for cookies produced of those powders.

The experiment shows that an increase in temperature will cause the product’s color to be more red and yellow, lowering the powder yield, and also increase the coarse fiber content of the alkalized-product.

Powder size analysis, TPA, and acceptance test show that the produced cocoa powder can be utilized for a substitution or mixing flour as there is no significant difference observed among them. It contains rich fiber that is important for dietary food.

Poultry agro-industry generates huge amounts of solid wastes, such as poultry litter (PL) and feathers. Feathers, possessing a substantial amount of organic nitrogen, are mainly converted into feather meal (FM) through the hydrothermal process; however, microbial conversion into feather hydrolysates (FH) is increasingly being focused on. Since waste management strategies include the use of organic wastes as soil fertilizer, PL, FM, and FH were evaluated as fertilizers for lettuce in comparison to urea.

Lettuce seedlings were transplanted to soil pots containing FH, obtained through feathers’ bioconversion by Bacillus sp. CL18, FM, PL, urea, and unfertilized controls. Partial chemical characterization of FH, FP, and PL was performed. Fertilization treatments were applied to reach 180 kg N/ha. Growth, dry biomass, and chlorophyll contents of lettuce were evaluated to indicate fertilizer performance.

After 60 days of greenhouse lettuce cultivation, leaves per plant were superior after FH treatment. Lettuce fertilized with urea and FH presented higher and similar foliar areas. FH treatment resulted in increased dry weight (DW) of leaves, which then decreased in the order urea > FM > MM ~ controls > PL. Dry weight of leaves and roots was 33% and 64% higher with FH than with urea. Leaf total chlorophyll content was higher with FH, but similar to urea and FM. Lettuce growth was negatively affected by PL when compared to controls.

FH, obtained from microbial processing of abundant and inexpensive feathers, could be a candidate N-rich fertilizer for lettuce cultivation.

The consecutive amendment of composted tannery sludge (CTS) could promote changes in the status of soil microorganisms. Thus, this study evaluated the changes on microbial C and enzyme activities in soil after 9 years of CTS amendment.

CTS was amended from 2009 to 2018 at five rates: 0, 2.5, 5, 10, and 20 ton ha−1. In 2018, the soil chemical properties (pH, electric conductivity, P, K, Cr, and total organic C), microbial C and enzyme activities were evaluated after 30 days from the amendment.

The values of chemical properties increased after nine years of CTS application. The content of microbial C and the enzyme activities increased with the amendment of 2.5 and 5 ton ha−1, and decreased with the amendment of 10 and 20 ton ha−1.

This study showed that the amendment of 10 and 20 ton ha−1 of CTS increased soil pH and Cr concentration and promoted a decreasing on soil microbial C and enzyme activities.

The main objective of the present study was to evaluate the effects of compost formulation made from agricultural by-products and thermal treatment of fresh mushrooms on the postharvest quality parameters.

Quail manure was evaluated as an alternative ingredient to the broadly used chicken manure for compost preparation. In addition, the treatment of fresh mushrooms by hot water to extend shelf-life was tested. Quality parameters including color (browning due to microbial activity), cap opening and the weight loss (senescence) were evaluated.

The nature of the manure employed as base material in the substrate can affect the postharvest browning ratio of mushroom. However, no significant differences in Δb value, weight loss or cap opening were noticed between two different substrates during storage of harvested mushrooms. The cap opening ratio was further retarded while applying thermal treatment to the mushrooms at 55 °C.

The use of chicken manure as base material to prepare mushroom substrate reduces mushroom browning during storage compared to quail manure, although mushrooms from quail compost are whiter at picking. Postharvest treatment at 45 °C for 4 min was the best to minimize the weight loss.