International Journal of Recycling of Organic Waste in Agriculture
Volume:12 Issue: 4, Autumn 2023

 This study aimed to verify the effects of the application of carnauba waste on the biological attributes, organic carbon content, and hydrothermal regime of soil.

The experiment was performed in randomized blocks with six treatments and four replicates. The treatments were as follows: (1) NPK (recommended dose of synthetic fertilizers: 100:180:86 kg ha-1 NPK); (2) surface application of 10 t ha-1 carnauba waste; (3) incorporation of 10 t ha-1 carnauba waste; (4) surface application of 10 t ha-1 carnauba waste + NPK; (5) incorporation of 10 t ha-1 carnauba waste + NPK; and (6) bare and unfertilized soil (control).

 Treatments that received carnauba waste showed higher amounts of organic carbon, carbon accumulation, microbial biomass, and CO2 in the surface layer of the soil, from 0.0 to 0.10 m, compared to control treatments. Although there was no difference in the respiration rates between the treatments, the metabolic quotient tended to decrease in the treatments that received carnauba waste. Treatment with carnauba waste resulted in a decreased soil bulk density in the surface layer. Soil covered with carnauba waste maintained higher soil moisture and lower temperatures. Multivariate analysis showed that applying carnauba waste with NPK to the soil surface significantly affected soil quality attributes.

 The use of carnauba residue combined with fertilizer can improve the microbiological attributes of the soil, increase the organic carbon content in the soil, and reduce thermal amplitude, which can help maintain higher levels of moisture in the soil.

Recent trends in land use and the effects of climate change resulted in the decline of organic matter content of the soils. Since crop management systems play an important role in soil carbon sequestration, therefore our aim was to determine the long-term effects of different organic fertilizers on soil respiration and its driving factors. The research work was carried out in two long-term experiments on sandy soil. The field and laboratory measurements of soil respiration were done in fallow, farmyard manure, farmyard manure + fertilizer, green manure and in sewage sludge compost (18 and 27 t ha-1) treatments. In addition, soil physical-chemical parameters were measured for complex evaluation. The results of laboratory and field soil respiration measurements were usually consistent with each other. The most intensive soil respiration was measured in sewage sludge compost treatments and in farmyard manure with NPK. In these treatments, the organic matter input and the positive changes in the physical and chemical properties of sandy soil stimulated the soil life, which resulted in more intensive soil respiration and enzyme activities. According to the results of correlation analysis the soil respiration was significantly influenced by the organic matter content, pH and moisture content of the soil. This study indicated the importance of replenishing the soil with organic matter, which can contribute to the maintenance of soil quality. In addition, the application of sewage sludge compost can be well utilized in agriculture for nutrient supply and improving carbon sequestration of sandy soil.

Organic matter has significant effects on phosphorus (P) retention in soil. Applying vermicompost (VC) as an organic amendment is an eco-friendly approach to increase sustainability in agriculture. There is a high potential of P loss by leaching or surface runoff from coarse-textured soils. Column leaching experiments were conducted to determine the effect of VC on P mobility in a P fertilized sandy loam soil .

Soil columns were amended with different VC dosages (2% VC, 3% VC, and 5% VC w/w) and leached with distilled water for 31 days. Phosphorus, base cations and anions concentration, EC, and pH were analyzed in leachates and P species, leaching rate, and fractions in amended soils were determined, too.

The HPO4-2 and MgHPO4 (aq) were the dominant species in the leachates and their highest total concentration was observed in 5% VC-amended columns. Vermicompost increased P leaching and its leaching rate ranged from 0.41 mg kg-1day-1 for control to 0.59 mg kg-1day-1 for 5% VC-amended columns. With increasing VC dosage Res–P, NaOH–P, and KCl–P fractions decreased, but the HCl-P fraction increased.

Results indicate that the VC with increasing moderately labile P fraction (HCl-P) and HPO4 -2 and MgHPO4 (aq) species can enhance P leaching from sandy loam soil .

To evaluate the effect of palm bunch ash and mycorrhiza on soil properties and the performance of cucumber in Calabar.

Factorial combination of five levels of palm bunch ash – PBA (0, 3, 6, 9 and 12 t/ha) and two mycorrhiza treatments (inoculated and non-inoculated), laid out in randomized complete block design (RCBD) with three replications. Data were collected on crop growth and yield indices, soil properties (physical, chemical and biological) each year, then combined and analyzed. Duncan’s Multiple Range Test (DMRT) at 5% probability was used to compare the means.

There was increase in soil pH, organic carbon, phosphorus, potassium, calcium and magnesium as a result of PBA and mycorrhiza applications. PBA, mycorrhiza and their interactions significantly (p <.0. 05) influenced the vegetative growth and fruit yield of cucumber. Cucumber treated with 12 t/ha PBA had the highest vegetative growth and fruit yield values, which however were similar with those obtained from cucumber treated with 9 t/ha of PBA. Cucumber inoculated with mycorrhiza had superior growth and fruit yield than non-inoculated cucumber. The interaction of mycorrhiza and 12 t/ha PBA produced the highest values of vegetative growth and fruit yield indices, though similar with the interaction of mycorrhiza and 9 t/ha PBA.

Palm bunch ash was sufficient at 9 t/ha and is therefore recommended with mycorrhiza for effective soil nutrient enhancement and optimum cucumber production in Calabar.

(i) To evaluate the efficacy of spinach in dry powdered and liquid form as a sustainable substitute for chemical fertilizers; (ii) To analyze and compare the morphological and yield-related parameters of Solanum melongena plants using spinach powder and compost as compared to the control treatment.

In a pot experiment, Solanum melongena seeds were sowed in soil mixed with spinach powder and compost while the control pots were without any amendment to the soil. The spinach -amended soil, compost-amended soil, and control soil sample were compared in terms physiochemical characteristics like pH , EC ,TDS, organic matter , nutrients i.e. nitrogen , phosphorus, potassium ,calcium ,magnesium and heavy metals. While, plant morphological traits plant height, root length, numbers of flowers and fruits were recorded.

The pH of spinach-amended soil was slightly alkaline before plantation as compared to control soil. The nitrogen, phosphorus, and potassium content in spinach dry powder was 15%, 36% and 49%, respectively. The organic carbon content was 56% with moderate amount of micronutrients like calcium, magnesium and iron. Spinach powder-amended soil significantly improved the plant morphological characteristics like stem height, root length and able to produce more flowers and mature fruits as compared to compost-amended soil and control soil.

  The use of spinach in powder and liquid concoction was a suitable alternative to chemical fertilizers. It was able to deliver all major macro- and micronutrients to soil thus improving the fertility and has significant impact on plant growth and yield.

This study assessed the fertilizing potential and environmental impacts of recycling the blood meal powder (BMP) produced in the abattoir as an organic fertilizer in agriculture.

In this study, a 70-day laboratory incubation experiment was conducted using a clayey calcareous soil to study the effects of adding abattoir BMP at three rates (1.5, 3.0, and 6.0 ton ha-1). At the end of the incubation period, the pH value, total C and N, inorganic N, and availability of macro- and micronutrient minerals (P, K, Cu, Fe, Mn, Ni, and Zn) were measured. Soil basal respiration, substrate-induced respiration, the abundance of culturable bacteria, fungi, and azotobacter, and dehydrogenase, alkaline and acid phosphomonoesterase, cellulase, invertase, protease, and urease enzymes activities were also determined as biochemical indicators of soil fertility.

The results showed that the BMP has potential as fertilizer because it increased C, N, P, and Zn as compared to the control soil. Furthermore, the abundance of culturable microorganisms and dehydrogenase activity increased in the amended soil, whereas the other soil enzyme activities and basal respiration did not show an increase. The calculation of the Hazard Quotient (HQ) and the soil quality index (SQI) indicated that 3.0-ton BMP ha-1 is an appropriate treatment to improve soil quality without environmental hazards.

The results indicate that abattoir BMP application increased the fertility status of calcareous soil without environmental threats.

A study was carried out during the 2021 dry season and 2022 rainy season to evaluate the differences in the performance, fruit longevity, mineral, and vitamin C compositions of two varieties of pepper (Capsicum chinense) cultivated using different organic amendments and inorganic fertilizer as a check. Poultry manure (PM), Tithonia diversifolia (TD), cattle manure (CM), inorganic fertilizer (NPK 15:15:15), and the control (CTRL) were used as treatments. Organic amendments were applied at a rate of 20 t ha-1, while NPK was applied at a rate of 180 kg ha-1. The experiment was a 2 x 2 x 5 factorial with three replications laid out in a Randomised Complete Block Design. Vegetative, yield, and quality parameters were collected. Results show that Caribbean red produced higher values for vegetative parameters, yield, and longer shelf life in season 1. In a similar vein, mineral compositions (Cu, Ca, and Mg) of the Caribbean red variety were found to be higher than that of the Efia variety. Results also indicated that the use of poultry manure was found to improve the vegetative parameters, increased the number of days to fruit shrinkage, and increased the Ca, Cu, Mg, and vitamin C content. This study, therefore, concludes that the use of the Caribbean red variety cultivated during the dry season (season 1) under the application of poultry manure will give the best vegetative performance, longer shelf life, and improved fruit minerals and vitamin C contents.

Application of organic manures, along with fertilizers, is important to maintain soil fertility to achieve higher productivity. In reality, the farmers apply organic manures and fertilizers in different proportions and quantities depending on their availability and purchasing power of farmers. Organic manures also help to enhance soil carbon stocks and soil biological activities. Hence, this study aimed to assess the role of organic manures on soil carbon stocks and soil enzymes in intensively managed ginger production systems.

Farmers’ fields based study was conducted in Shivamogga district coming under Hilly Zone of Karnataka, India. The information on use of organic manures and fertilizers for ginger production were collected from 60 growers and they were grouped into three categories using the K-factorization statistical tool. Soil samples were collected after crop harvest and analysed for soil carbon stocks and soil enzyme activities. The mean values of 3 categories of farmers were compared using suitable statistical tools.

Added organic manure and the soil organic carbon (SOC) varied significantly among high and low organic manure applications. Incremental variations were observed in the order of Category 3 > Category 2 > Category 1 ginger fields. Enzyme activities were found higher in fields applied with high organic manures. Both soil carbon stocks and soil enzyme activities exhibited strong and positive correlations with organic manures.

The study revealed that application of organic manures in intensively managed ginger production systems helps to enhance soil carbon stocks and maintain soil biological activities.

Degraded soils are associated with low organic matter and nutrient contents, which limit their productive capacity to produce sufficient food. Improving the productivity of degraded soils is key to achieving sustainable food production and tackling global food crises.

A study was carried out between September 2021 to March 2022 in a greenhouse at the University of Nigeria Nsukka Teaching and Research Farm to evaluate effect of cow bone meal (CBM) application on soil physicochemical properties and performance of cucumber grown on a degraded coarse-textured soil. The study treatments were: CBM10 (CBM at 10 t ha-1; equivalent to 22 g per 5 kg soil), CBM20 (CBM at 20 t ha-1; equivalent to 44 g per 5 kg soil), and NPK 20:10:10 fertilizer applied at recommended rate 150 kg ha-1 (0.33 g per 5 kg soil) and control.

CBM treatments application had remarkable positive effects on the soil physicochemical properties as well as on cucumber performance. Relative to the initial soil status, CBM application increased organic C by 139 -179%; available P by 388-396% and total N by 78-111%. Summarily, CBM20 treatment outperformed NPK fertilizer treatment on the measured soil parameters and cucumber performance, while CBM10 treatment had comparable effects with NPK treatment.

The results obtained demonstrate the effectiveness of CBM in improving the physicochemical properties of a degraded soil. Further research work (under field conditions) is required to validate the findings of this study prior to practical implementation by end users.

A study was conducted to transform bovine blood, a slaughterhouse by-product, into an organic source of nitrogen, which is otherwise disposed of through sewer systems only to pollute the nearby water bodies.    The annual blood production in the Khulna City Corporation (KCC) slaughterhouses was estimated, blood samples were collected, and blood meals were manufactured and characterized for their nitrogen content and other nutritional values. The best blood meal was sorted out, incubated in soil, and applied to spinach (Spinacea oleracea L.) to assess the effects of the final product on plant and soil health. This investigation estimated the annual disposal of 58.62 tons of bovine blood from the KCC slaughterhouses.  The conventionally derived blood meal (BMc) attained the higher amount of primary nutrients (NPKS), while oven-dried blood meal (BMod) attained the higher amount of secondary nutrients (Ca and Mg), micronutrients (Fe, Cu, and Mn) and heavy metals (Cr, Pb, Ni). An increasing rate of blood meal incubation in soil increased available N and N-mineralization with an incubation time of up to 90 days. Blood meal application to spinach at a rate of 5 t/ha had evident higher productivity and better N-utilization efficiency although application rate above 5 t/ha declined crop performance.   The outcome of the study suggests that blood meal can be used as an organic source of nitrogen and the application of blood meal has manifold benefits if applied at a judicious rate preferably less than or equal to 5 t/ha.

Poor management of chicken litter by the poultry industry has caused many environmental issues. Biochar’s unique characteristics make poultry litter-to-biochar conversion an intriguing management option thus, could be utilized as an organic fertilizer for plant nutrients. In this research, poultry litter was converted into biochar, which offers a range of possible applications, including analyzing key nutrients, improving air and water quality, conditioning soil, and neutralizing acidic soils. Fresh poultry litter was pyrolyzed for 20 minutes at a temperature of 500 oC in an oxygen-restricted muffle furnace to produce biochar. The biochar was examined chemically and physically using a variety of techniques. These included microwave plasma atomic emission spectroscopy (MP-AES), the scanning electron microscope (SEM), the Fourier transform infrared (FTIR) spectroscopy, and thermo gravimetric analysis (TGA and DTG). The pyrolysis output was 56.38%, 32.20% ash, 2.00% moisture, 0.60 kg/m3 bulk density, pH 9.65, and 0.00314 dS/m EC. The mineral elemental analysis gave 621.73 mg/kg calcium, 63.65 mg/kg potassium, 48.94 mg/kg magnesium, 13.14 mg/kg sodium, and 11.85 mg/kg phosphorus.  FTIR showed the presence of functional groups which could act as cation adsorbents. SEM pictures showed the sample’s amorphous, non-uniform surface. TGA and DTG curves showed mass loss and sample breakdown as the temperature climbed. Poultry litter converted to biochar can act as a nutrient-rich soil conditioner to address mineral deficits in fruits and vegetables grown in acidic soils. This is a good way to recycle agricultural trash.

One of the primary wastes of the sugar industry that has the potential to be converted into fertilizer is filter cake. Organomineral fertilizer  is proposed as a promising approach. Therefore, this research evaluated the efficiency of various filter cake-based organomineral formulations for sweet maize growth under different fertilization rates. The treatments comprised of seven formulations of filter cake-based fertilizers (filter cake (F), biochar (B), organomineral filter cake, organomineral biochar (OB), organomineral filter cake + humic acid, organomineral biochar + humic acid, and conventional mineral fertilizer (M)) and four rates (40, 80, 120, and 160 kg N ha−1) based on the nitrogen (N) contents of each fertilizer. Furthermore, fertilizers applied to maize, and growth performance, nutrient use efficiency (NUE), and soil quality were assessed. Maize fertilization using F, B, and OB at different rates resulted in the highest vegetative growth performance, NUE, and residual soil status. F fertilizer produced the optimal plant height, leaf area, and stem diameter for maize. The application of OB fertilizer was most efficient in N uptake, potassium uptake, and potassium recovery, demonstrating values of 42.56%, 91.8%, and 115.4%, respectively. B fertilizer provided a better residual of P (93.4%) than M and a higher organic matter content (224.7%) than the negative control. As per our findings, OB is the best treatment for increasing growth performance, NUE, and soil quality with an optimal dose of 0.96 t ha−1. Fertilization using OB has significantly improved sweet maize agronomic traits and soil quality

Waste disposal poses serious environmental challenges to mankind. This precipitated the quest for an eco-friendly waste management approach to minimize the challenges wastes pose to the ecosystem and proffer alternative use for these wastes.

A field study was carried out at the University of Nigeria Nsukka Teaching and Research Farm to investigate the effects of composted sawdust-household waste (SHW) with or without inorganic fertilizer addition on soil chemical properties and tomato performance. The experiment was arranged in a randomized complete block design with five treatments and three replications. The treatments were: 50% NPK + SHW 20 t/ha, SHW 40 t/ha, SHW 20 t/ha, 100% NPK, and Control.

The amended treatments, except 100% NPK, increased the soil pH by 3-8%, available P by 14-29%, and soil organic matter by 1.5-9.8%. Control and 100% NPK treatments had no significant effect on the soil’s chemical properties. SHW 40 t/ha had significantly taller plants and a higher number of plant leaves relative to other treatments. The amended treatments recorded significantly weightier fresh root weight, dry root weight, fresh shoot weight, and dry shoot weight relative to the control treatment. Overall, SHW treatments application had more pronounced effects on plant biomass than on plant vegetative growth.

The study suggests that composted SHW can be a viable option over chemical fertilizer for tomato cultivation as well as good soil conditioners.

Soil nutrient depletion and possible degradation have been highlighted as key reasons for lower crop yields in Nigeria. The present study was aimed to assess the effect of Trichoderma harzianum on the bioconversion of different solid organic wastes into compost and its application on cucumber.

 The treatments were 3 levels of T. harzianum inoculum (0, 5 and 10 ml) and 4 types of solid organic wastes (maize-cob, groundnut-pods, sawdust and their mixture) and soil. A small portion of the solid wastes (40 g) was weighed into each incubation jar with 10 g of chopped Guinea grass (Panicum maximum) and 20 g each of poultry manure. The compost was thereafter incubated for 12 weeks. 

Total N, P and K contents were significantly (p < 0.05) highest in the mixture of solid organic wastes (22800 mg/kg), corn cobs (2600 mg/kg) and groundnut pods (2300 mg/kg), respectively. The growth parameters (plant height, number of leaves, leaf length, leaf girth and stem girth) significantly increased with increasing T. harzianum concentration. The highest fruit weight (105.84 g/plant) of cucumber was obtained in compost inoculated with 10 ml/pot of T. harzianum. Compost made of corn-cobs, groundnut pods and the mixture of the solid wastes significantly promoted the growth parameters. The highest fruit weight (117.99 g/plant) was obtained in a pot treated with a mixture of solid wastes.

 The use of T. harzianum in biotransformation of organic wastes could be a better tool to improve soil conditions thus enhancing the productivity of cucumber.