Animal Manure Research Articles

Utilizing Waste Materials to Enhance Crop Production: A Review

Waste management is a crucial aspect of modern societies, encompassing various activities to ensure the safe and effective disposal of waste materials. It can be classified as hazardous waste, electronic trash (e-waste), industrial waste, and municipal solid waste (MSW). Sustainable waste management practices aim to reduce environmental impact while protecting public health. Urbanization leads to increased residential water consumption, however reusing wastewater for non-potable applications like agriculture can be cost-effective. The overall costs of delivering wastewater for agricultural reuse, including treatment, storage, and transportation, are less the total costs of safe environmental disposal alternatives. Drainage may also be a source of macronutrients (nitrogen, phosphorus, and potassium), which reduces the cost of wastewater for agricultural reuse. The adoption of these principles could lead to a 48% reduction in global greenhouse gas emissions by 2030. The management of hazardous waste, including toxic, flammable, corrosive, or reactive materials, is also a significant concern. In order to safeguard public health and stop the spread of infectious illnesses, animal manure management is crucial. The global generation of construction and demolition waste is expected to double by 2025, with the majority generated in Asia. Sustainable waste management practices are necessary to ensure public health and the environment.

Study of Steroid Estrogen Loss in Soil after the Application of Composted Manure as a Fertilizer

Steroid estrogens (SEs) play a significant role as endocrine-disrupting substances, and one of their major sources is animal manure. However, there is limited information available regarding the loss of SEs in farmland soil after the application of commercial composted animal manure or fertilizers. To address this gap, our study aimed to simulate rainfall and flood irrigation scenarios and investigate the loss characteristics of SEs, as well as Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorus (TP) in runoff from soil–manure mixtures. The results demonstrated that the loss concentrations of SEs (73.1 ng/L of the mean E2β active equivalent factor) presented a potential environmental risk. Additionally, substituting composted manure with commercial organic fertilizers lead to a significant reduction in TP (maximum 56%) and TN (maximum 24%) loss. Consequently, the application of commercial organic fertilizers offers considerable advantages in maintaining nitrogen and phosphorus fertilization efficiency while controlling SEs loss. Furthermore, our study explored the synergistic pollution mechanism among these pollutants and observed significant correlations between SEs and TN, TP, and COD loss concentrations, indicating the simultaneous occurrence and migration of these pollutants in agricultural non-point source pollution. These results provide valuable insights into the environmental risk associated with SEs from agricultural non-point sources.

The contribution of natural and anthropogenic causes to soil acidification rates under different fertilization practices and site conditions in southern China

Excessive application of mineral fertilizers has accelerated soil acidification in China, affecting crop production when the pH drops below a critical value. However, the contributions of natural soil acidification, induced by leaching of bicarbonate, and anthropogenic causes of soil acidification, induced by nitrogen (N) transformations and removal of base cations over acid anions, are not well quantified. In this study, we quantified soil acidification rates, in equivalents (eq) of acidity, by assessing the inputs and outputs of all major cations and anions, including calcium, magnesium, potassium, sodium, ammonium, nitrate, bicarbonate, sulphate, phosphate and chloride, for 13 long-term experimental sites in southern China. The acidification rates strongly varied among fertilizer treatments and with the addition of animal manure. Bicarbonate leaching was the dominant acid production process in calcareous soils (23 keq ha−1 yr−1) and in non-calcareous paddy soils (9.6 keq ha−1 yr−1), accounting for 80 % and 68 % of the total acid production rate, respectively. The calcareous soils were strongly buffered, and acidification led no or a limited decline in pH. In contrast, N transformations were the most important driver for soil acidification at one site with upland crops on a non-calcareous soil, accounting for 72 % of total acid production rate of 8.4 keq ha−1 yr−1. In this soil, the soil pH considerably decreased being accompanied by a substantial decline in exchangeable base cation. Reducing the N surplus decreased the acidification rate with 10 to 54 eq per kg N surplus with the lowest value occurring in paddy soils and the highest in the upland soil. The use of manure, containing base cations, partly mitigated the acidifying impact of N fertilizer inputs and crop removal, but enhanced phosphorus (P) accumulation. Combining mineral fertilizer, manure and lime in integrative management strategies can mitigate soil acidification and minimize N and P losses.

Toxicity assessment of animal manure composts containing environmental microplastics by using earthworms Eisenia andrei

Nowadays, animal manure composting constitutes a sustainable alternative for farmers to enhance the level of nutrients within soils and achieve a good productivity. However, pollutants may be present in manures. This study focuses on the detection of environmental microplastics (EMPs) into composts, as well as on the assessment of their potential toxicity on the earthworm Eisenia andrei. To these aims, animals were exposed to two types of compost, namely bovine (cow) and ovine (sheep) manure, besides to their mixture, for 7 and 14 days. The presence and characterization of EMPs was evaluated in all the tested composts, as well as in tissues of the exposed earthworms. The impact of the tested composts was assessed by a multi-biomarker approach including cytotoxic (lysosomal membrane stability, LMS), genotoxic (micronuclei frequency, MNi), biochemical (activity of catalase, CAT, and glutathione-S-transferase, GST; content of malondialdehyde, MDA), and neurotoxic (activity of acetylcholinesterase, AChE) responses in earthworms. Results indicated the presence of high levels of EMPs in all the tested composts, especially in the sheep manure (2273.14 ± 200.89 items/kg) in comparison to the cow manure (1628.82 ± 175.23 items/kg), with the size <1.22 μm as the most abundant EMPs. A time-dependent decrease in LMS and AChE was noted in exposed earthworms, as well as a concomitant increase in DNA damages (MNi) after 7 and 14 days of exposure. Also, a severe oxidative stress was recorded in animals treated with the different types of compost through an increase in CAT and GST activities, and LPO levels, especially after 14 days of exposure. Therefore, it is necessary to carefully consider these findings for agricultural good practices in terms of plastic mitigation in compost usage, in order to prevent any risk for environment health.

Assessment of nutrient flows in maize-based farming system by smallholder farmers for sustainable production in Ikara, Kaduna State

Nutrient depletion is one of the major causes of decreased crop yield, and a threat to food security and sustainable crop production. NutMon- toolbox was used to determine nutrient flows and partial nutrient balances of maize-based smallholders’ farming system. Data was collected using structured questionnaire from 15 randomly selected farmers, with five farmers each in three villages. Composite soil samples were also taken from each of the three plots. At crop maturity, samples of crop products and residues were randomly taken from the selected fields. Nitrogen, P and K contents in soil and crop material was used to calculate nutrient flows and partial balances. Results obtained revealed that mineral fertilizer flow, averaged 349.20kg N yr-1 and 81.45kg K yr-1 and were lower than 376.65kg N yr-1 and 431.44kg K yr-1 organic input. However, phosphorus in mineral fertilizer (55.78kg P yr-1) was higher compared to phosphorus (51.06 kg P ha-1 yr-1) in organic input. Nitrogen, phosphorus and potassium for maize seeds and crop residue were all negative. The partial nutrient balances were positive 53.45kg N ha-1 yr-1 and 79.40kg K ha-1 but negative 1.10kg P ha-1 yr-1. Harvesting of crops for food, without incorporation of crop residue into the soil, were the most important sources of nutrient mining in smallholder production system. Integrated soil fertility management practices that favour the buildup of soil organic matter and use of animal manure should be encouraged through effective extension services at Ikara, Kaduna State, Nigeria.

Priority establishment of soil bacteria in rhizosphere limited the spread of tetracycline resistance genes from pig manure to soil-plant systems based on synthetic communities approach

The spread of antibiotic resistance genes (ARGs) in agroecosystems through the application of animal manure is a global threat to human and environmental health. However, the adaptability and colonization ability of animal manure-derived bacteria determine the spread pathways of ARG in agroecosystems, which have rarely been studied. Here, we performed an invasion experiment by creating a synthetic communities (SynCom) with ten isolates from pig manure and followed its assembly during gnotobiotic cultivation of a soil-Arabidopsis thaliana (A. thaliana) system. We found that Firmicutes in the SynCom were efficiently filtered out in the rhizosphere, thereby limiting the entry of tetracycline resistance genes (TRGs) into the plant. However, Proteobacteria and Actinobacteria in the SynCom were able to establish in all compartments of the soil–plant system thereby spreading TRGs from manure to soil and plant. The presence of native soil bacteria prevented the establishment of manure-borne bacteria and effectively reduced the spread of TRGs. Achromobacter mucicolens and Pantoea septica were the main vectors for the entry of tetA into plants. Furthermore, doxycycline stress promoted the horizontal gene transfer (HGT) of the conjugative resistance plasmid RP4 within the SynCom in A. thaliana by upregulating the expression of HGT-related mRNAs. Therefore, this study provides evidence for the dissemination pathways of ARGs in agricultural systems through the invasion of manure-derived bacteria and HGT by conjugative resistance plasmids and demonstrates that the priority establishment of soil bacteria in the rhizosphere limited the spread of TRGs from pig manure to soil-plant systems.

Phosphorus Release Dynamics from Ashes during a Soil Incubation Study: Effect of Feedstock Characteristics and Combustion Conditions

Recovering phosphorus (P) through combustion from waste streams, like wastewater sludge and animal manure, offers a promising solution. This research explores the P release patterns in different ashes derived from secondary raw materials, using a long-term soil incubation lasting 160 days. The study evaluated the P release dynamics in five types of ashes from enhanced biological phosphorus removal (EBPR) systems and pig slurry burned at different temperatures. According to the results, a primary effect was observed on P bioavailability during the initial incubation period. All tested ashes release more than 50% of the total P applied between days 5 and 10. Ashes from EBPR exhibited higher P release than those from pig manure, indicating ash origin as a key factor in P release. Additionally, combustion temperature was crucial, with higher temperatures resulting in increased P release rates. Furthermore, the Pearson correlation revealed a strong relationship between the characteristics of the ashes and the amount of P release. Overall, these findings suggest that ashes could be a valuable P-source for agriculture avoiding the process of wet chemical P extraction, thus reducing both economic and environmental costs.

A GIS-based analysis of heavy metals around Otukpo rice mill in Benue state

Heavy metals are primarily sourced from natural pedo-geochemical backgrounds and anthropogenic occurrences like composting, sewage sludge, aerosol deposition, and waste animal manure. The study aims to determine the heavy metals within the rice mill in Otukpo to understand the spatial distribution with the objectives to examine the heavy metals within the identified activity areas in the Otukpo rice mill, to determine the spatial distribution of heavy metals within the study area and to compare heavy metal values with the acceptable limits. Soil samples were collected from ten locations at Otukpo Rice Mill to analyze heavy metal concentrations. The samples were collected using sterile bottles and a stainless trowel, and the soil samples were analyzed for the concentrations of Cadmium, Copper, Lead, Nickel, Zinc, Mercury, Iron, Arsenic, and Chromium using the Atomic Absorption Spectrophotometry method. The result was analyzed using interpolation to see the variation of the Heavy metals within the various activity areas. The result of the study reveals that Iron has the highest concentration at the Entrance point and lowest at the Generator house with a range value of 3.92 – 1.12mg/kg respectively. The highest concentration of Zinc was recorded at the Mechanic workshop while the lowest is at the Drying point with a range value of 0.135 – 0.872mg/kg respectively. The Husk dumpsite recorded the highest concentration of Copper (0.666mg/kg) with the Drying point recording the least (0.088 mg/kg). The study reveals uneven concentrations and highlights the effectiveness of the Geographic Information System in mapping heavy metal concentrations.

Ceftiofur in swine manure contributes to reducing pathogens and antibiotic resistance genes during composting

Aerobic composting is a common way for the disposal of feces produced in animal husbandry, and can reduce the release of antibiotic resistance genes (ARGs) from feces into the environment. In this study, we collected samples from two distinct treatments of swine manure compost with and without ceftiofur (CEF), and identified the ARGs, mobile genetic elements (MGEs), and bacterial community by metagenomic sequencing. The impacts of CEF on the bacterial community composition and fate of ARGs and MGEs were investigated. With increasing composting temperature and pH, the concentration of CEF in the manure decreased rapidly, with a degradation half-life of 1.12 d and a 100% removal rate after 10 d of aerobic composting. Metagenomics demonstrated that CEF in the manure might inhibit the growth of Firmicutes and Proteobacteria, thereby reducing some ARGs and MGEs hosted by these two bacteria, which was further confirmed by the variations of ARGs and MGEs. A further redundancy analysis suggested that pH and temperature are key environmental factors affecting ARG removal during composting, and intI1 and bacterial communities also have significant influence on ARG abundance. These results are of great significance for promoting the removal of some ARGs from animal manure by controlling some key environmental factors and the type of antibiotics used in animals.

Overview of Resource Utilization of Livestock and Poultry Manure

In recent years, with the development of animal husbandry, more and more livestock and poultry manure has been generated. Currently, the most common methods for treating livestock and poultry manure are anaerobic fermentation and aerobic composting. Aerobic composting is a technology that uses animal manure for high-temperature composting and fermentation to degrade organic matter and convert it into humic substances. Anaerobic fermentation is an energy utilization technology that converts organic matter into combustible gases such as CH4 through the action of anaerobic microorganisms and produces biogas slurry and sludge. This article reviews two treatment methods for livestock and poultry manure, aerobic composting and anaerobic digestion, in order to provide reference for the research of humic acid organic fertilizers.

A data-driven framework to inform sustainable management of animal manure in rural agricultural regions using emerging resource recovery technologies

Thermochemical conversion technologies are emerging as preferred resource recovery practices for managing animal manure in agricultural regions. Although the implementation of such technologies has been previously studied, difficulties exist in maintaining balance between high rate of resource recovery and low environmental, economic, and social impacts, particularly in rural regions with limited resources. We developed a data-driven framework by integrating machine learning with life cycle thinking that can be used as an open-source tool to help overcome these barriers. The framework was applied to compare two emerging technologies: pyrolysis versus hydrothermal carbonization for managing the excess poultry litter in a rural agricultural region. Among different machine learning models, random forest regression was the most successful to predict resource recovery of both technologies. Next, sustainability analysis indicated that the environmental (global warming), economic (annual worth), and social (system intrusiveness) impacts of pyrolysis was lower than hydrothermal carbonization. Finally, the framework revealed that implementation of pyrolysis at 600 °C for 1 h with the heating rate of 20 °C/min would result in the highest rate of resource recovery that corresponded to the lowest impacts. These results can be helpful in providing operational conditions for implementing emerging resource recovery technologies in rural agricultural regions.

The implications of the Russian invasion of Ukraine for African economies: A CGE analysis for Ethiopia

The Russian invasion of Ukraine contributed to soaring world market prices of many commodities with severe repercussions for many African countries. This study examines the implications of the 2022 world market price increases for wheat, fuels, and fertilizers for Ethiopia. Using a computable general equilibrium (CGE) model, the study shows negative impacts on GDP, wage rates, and households’ consumption in the country. The effects of fertilizer and petroleum price changes are notable and unequal across production sectors. With increasing import prices of inorganic fertilizers, crop growing activities substitute inorganic fertilizers with animal manure reducing the use of manure as cooking fuel. The effects on urban households are more severe than the effects on rural households. Policies supporting biofuels and biogas digesters may dampen the adverse effects stemming from petroleum price surges.

Animal Manure as an Alternative Bioenergy Resource in Rural Sub-Saharan Africa: Present Insights, Challenges, and Prospects for Future Advancements

Energy availability is a pivotal driver in fostering sustainable socio-economic development. However, sub-Saharan Africa (SSA) grapples with paradoxes headlined by abundant energy resources but with the world’s lowest access to clean energy index per capita. Faced with a lack of access to clean energy sources like electricity, rural areas in the majority of SSA countries almost exclusively depend on biomass-fuels, mostly fuelwood, leading to heightened respiratory health risks as well as environmental degradation and accelerated climate change. As an alternative, this review investigates the potential of animal manure as a sustainable energy resource for rural SSA households, emphasising its utilisation as a feedstock for biogas production using anaerobic digestor technology. Results show that despite the abundance of literature that reports on successes in lab-scale bioreactor optimisation, as well as successes in the initial rollout of biogas biodigester technology in SSA with the help of international collaborators, the actual uptake of biogas bioreactor technology by rural communities remains low, while installed bioreactors are experiencing high failure rates. Resultantly, rural SSA still lags significantly behind in the adoption of sustainable clean energy systems in comparison to rural communities in other regions. Among some of the hurdles identified as driving low technology assimilation are onerous policy requirements, low-level government involvement, high bioreactor-instalment costs, the lack of training and awareness, and water scarcity. Prospects for success lie in innovative technologies like the low-cost portable FlexiBiogas system and private–public partnerships, as well as flexible energy policy frameworks. Bridging the knowledge-implementation gap requires a holistic approach considering cultural, technological, and policy aspects.

The Role of Organic Farming in Sustainable Agriculture

Organic farming, as a sustainable alternative to conventional high-input practices reliant on synthetic fertilizers, fungicides, and pesticides, prioritizes the vitality of soil as a living ecosystem. Embracing practices such as crop rotation, animal manures, crop residues, green manures, and biological pest and disease control, organic agriculture aims to uphold soil health and productivity. By meeting present food demands in an environmentally conscientious manner, organic farming also safeguards the needs of future generations, thereby preserving and nurturing our ecosystem. Modern agriculture has detrimentally impacted the environment, leading to issues such as decreased soil fertility, elevated water hardness, insect resistance development, reduced genetic diversity in plants, heightened levels of toxic residues in the food chain and animal feed, contributing to health problems and environmental degradation. In contrast, organic farming nurtures plants with essential macronutrients and micronutrients while simultaneously enhancing soil physical, chemical, and biological characteristics. Guided by the ethos of sustainability, organic farming prioritizes mitigating health risks linked to synthetic inputs and cultivating a healthier ecosystem. The minimal environmental footprint of organic farming positions it as a practical solution for tackling urgent concerns like soil degradation, water pollution, and global ecological well-being. Essentially, organic farming stands out as a beacon of sustainable agriculture, paving the way to reconcile food production with environmental conservation. Moreover, organic farming's low environmental impact presents an opportunity to rehabilitate and enhance degraded agricultural lands.

Comparison of the Effects of Different Organic Amendments on the Immobilization and Phytoavailability of Lead

Organic materials, such as straw, animal manure, and their processed product biochar, are known to exhibit agronomic effects and the ability to remediate heavy metal contamination. However, knowledge regarding the relative effects of different organic amendments in soils on heavy metal immobilization and phytoavailability remain limited. Consequently, the effects of maize straw (MS), chicken manure (CM), mushroom cultivation waste (MW), and sawdust biochar (SB) on the immobilization and phytoavailability of lead (Pb) in wheat plants were investigated in this study using pot experiments. The results showed that the artificial application of Pb reduced soil pH, while increasing the total organic carbon (TOC) and cation exchange capacity (CEC) to various extents. Furthermore, the Pb treatment increased the adsorption of Pb by wheat grains (0.83 mg∙kg−1), resulting in decreased above-ground dry biomass (43.16 g∙pot−1) during the maturity growth period when compared with the control check (CK) treatment. The MS + Pb and CM + Pb treatments increased the exchangeable Pb fractions in the soil, but had a limited effect on Pb accumulation in wheat grains compared with the Pb treatment. In contrast, the SB + Pb treatment effectively increased soil pH and TOC, while decreasing the fraction of exchangeable Pb forms and increasing the oxidizable and residual Pb fractions, compared with the Pb treatment. Moreover, the MW + Pb treatment also increased the soil pH and CEC, displaying the potential to increase soil TOC, in addition to substantially modifying the portioning of Pb from exchangeable forms to less bioavailable fractions. Both the MW and SB amendments significantly reduced Pb concentrations in wheat grains (0.49 and 0.70 mg∙kg−1,∙respectively), resulting in increased above-ground dry biomass (51.59 and 54.12 g∙pot−1, respectively). In summary, the application of organic amendments, especially MW, could be an effective measure for enhancing Pb immobilization in polluted soils, thereby reducing its uptake and translocation to crops.

Enhancing nutritional status, growth, and fruit quality of dried figs using organic fertilizers in rain-fed orchards: A case study in Estahban, Iran.

The majority of Iranian fig production is exported, making it one of the world's most well-known healthy crops. Therefore, the main objective of the current experiment was to investigate the effects of various types of organic fertilizers, such as animal manure (cow and sheep), bird manure (partridge, turkey, quail, and chicken), and vermicompost, on the nutritional status of trees, vegetative and reproductive tree characteristics, fruit yield, and fruit quality traits in dried fig cultivar ("Sabz"). According to the findings, applying organic fertilizers, particularly turkey and quail, significantly improves vegetative and reproductive characteristics. However, other manures such as sheep, chicken, and vermicompost had a similar effect on the growth parameters of fig trees. Additionally, the findings indicated that except for potassium, use of all organic fertilizers had an impact on macro and microelements such as phosphorus, nitrogen, and sodium amount in fig tree leaves. Also, based on fruit color analysis in dried figs, the use of all organic fertilizers improved fruit color. Moreover, the analyses fruit biochemical showed that the use of some organic fertilizers improved that TSS and polyphenol compounds such as coumarin, vanillin, hesperidin gallic acid and trans frolic acid. In general, the results indicated that the addition of organic fertilizers, especially turkey manure, led to increased vegetative productivity and improvement in the fruit quality of the rain-fed fig orchard.

Catalytic fast pyrolysis over heavy metals-containing livestock manure biochar catalyst for polystyrene upcycling

The perpetual market demand for polystyrene results in the gradual accumulation of polystyrene waste, placing a serious burden on the environment. This study proposed a promising method to upcycle polystyrene for styrene-derived monomers through catalytic fast pyrolysis. The metals-incorporated biochar catalysts were synthesized from heavy metals-contaminated manure waste for catalytic fast pyrolysis of polystyrene. The experimental results showed that the bimetallic biochar-derived catalyst containing Zn and Cr (Zn-Cr/C) was more conducive to the liquid production, with an extremely high yield of 88.22 wt%. Monometallic Pb-incorporated biochar catalyst (Pb/C) and bimetallic Zn-Cu co-doped on biochar (Zn-Cu/C) were more favorable for the production of pure styrene, with the mass yield of 61.26 wt% and 60.39 wt%, respectively. Additionally, the study elucidated a deep understanding of the reaction mechanisms involved in the catalytic fast pyrolysis of polystyrene. Simply put, this study introduced a new concept to convert heavy metal-contaminated animal manure into metal-incorporated biochar catalysts for catalytic conversion of polystyrene waste in pure styrene-based monomers.

Contemporary Agricultural Land Management Practices under Climate Change and Population Increase Scenarios: Insights from Tanzania’s Southern Highlands

This study investigated the impact of population growth and climate change on land management practices. The study was conducted in Mbinga district located in the Southern Highlands of Tanzania. Quantitative and qualitative research approaches were employed. Research data were collected using structured questionnaires, in-depth interviews, physical observation, focus group discussions and literature review. A total of 267 household heads were selected for this study. Also, the study used climate data from Tanzania Meteorological Authority, temperature and rainfall data over the past 40 years were collected (1981-2021). The findings revealed that, the area has experienced increased population and climate change incidences. The trend line for both minimum and maximum temperatures indicate a substantial increased trends at (P= 0.0018, R2=0.0005; P=0.0176, R2=0.02359) respectively. Contrariwise, the area has experienced decrease in rainfall totals at (P= 0.4385, R2=0.0008). It was revealed that, various traditional methods of land management practices including the use of animal manures, mulching, fallowing and the use of crop residues were affected by population increase and climate change. Farmers adopted new agricultural practices including the use of industrial fertilizers and reducing the size of contour terraces as the coping strategies for agricultural production against environmental deterioration caused by population increase and climate change. However, the sustainability of such practices is uncertain due to continued population increase and climate change scenarios. Therefore, the study recommends for introduction of sustainable land management practices that would instigate for sustainable food production for the changing population.

Enhancing the Fermentation Process in Biogas Production from Animal and Plant Waste Substrates in the Southeastern Region of Bulgaria

Annually, a huge amount of waste from plant biomass and animal manure is produced from agriculture and animal farming. Many studies provide information on the biomethane potential of agricultural and livestock wastes, but only a few studies have investigated the application of the substrates in combination. The objective of the study is to enhance the fermentation process in the digester for biogas production, obtained from animal and plant waste substrates. In four batch processes for three months, the temperatures and the residence time of the substrates in the fermenter were analyzed. Simultaneously, electricity and thermal energy were produced via cogeneration units, which were exported to the public grid and city heating network. The plant substrate is a silage mixture of corn and wheat waste. The animal substrate is a mixture of beef and pig manure. Animal and vegetable waste raw materials are collected and transported to the site, located in the region of southeastern Bulgaria. The total annual consumption of animal and plant waste is 17,971 t/year. The enhancement of the process leads to the production of 1,506,000 Nm3 CH4/a of methane, the generation of which requires 299.63 MWh/a of electricity and 649.09 MWh/a thermal energy.

Phytotoxicity Assessment of Different Animal Manure on Selected Vegetable Crops in Kashere Community, Gombe State, Nigeria

The present study evaluated the phytotoxicity effect of poultry, goat and cow manure on Okra, Tomato and Pepper vegetables using appropriate standard methods. In the current study, of the three different manure collected and used on the three vegetable crops, GI value of &lt;50% was recorded on Okra and Pepper seeds mounted on PM medium (48.51% and 41.36% respectively), GI value of between 50% and 80% was recorded on Okra, Tomato and Pepper seeds mounted on GM medium (64.76%, 79.77% and 73.70% respectively) also Pepper seeds mounted on CM medium (76.48%) and Tomato seeds mounted on PM medium (75.41%) while GI Value of &gt;80% was observed on Okra and Tomato Seeds mounted on a CM medium (81.63% and 94.10% respectively). Overall result of all the animal manure evaluated, poultry manures was phytotoxic on okra and pepper seed and moderately phytotoxic on Tomato seed based on the plant bioassay evaluated. It is possible that other chemicals that were not analyzed in this study could potentially be responsible for the phytotoxic effects of poultry manure on the vegetable seeds, indicating that some curing in the form of composting or vermicomposting may be necessary to degrade or reduce the presence of phytotoxic compounds in the poultry manure used for the study before use as soil amendments and thus would help to render the resultant end product environmentally safer.