Assessing the Impact of Organic Fertilizers on Wheat Yield and Soil Health

Thesis Abstract

The persistent reliance on chemical fertilizers in wheat production has raised concerns over soil degradation and environmental sustainability, prompting investigation into alternative nutrient management practices such as organic fertilization. This study aims to empirically assess the impact of organic fertilizers on wheat yield and soil health parameters, with the specific objectives to quantify yield differences, evaluate soil nutrient dynamics, and analyze the influence of organic input types on soil microbial activity over two growing seasons. Employing a randomized complete block design, the research was conducted on a 2-hectare field divided into four treatment plots integrated compost, poultry manure, vermicompost, and a control with no organic amendment. The study population consisted of 60 smallholder farmers within the region who supplied farm access and management cooperation. Data collection involved measuring wheat grain and biomass yields, soil physicochemical properties—including pH, organic matter, nitrogen, phosphorus, and potassium—using standard laboratory protocols, along with soil microbial activity assessed through enzyme assays and microbial biomass quantification. Instruments for data collection included portable soil testing kits, laboratory spectrophotometers, and microbial analysis equipment, while qualitative data on farmer practices were gathered through semi-structured interviews. Validity and reliability of the laboratory assays were ensured through calibration, standard reference materials, and replication. Quantitative data were analyzed using Analysis of Variance (ANOVA) to compare yield and soil parameters across treatments, followed by multiple comparisons to identify significant differences, with regression analysis employed to elucidate relationships between soil health indicators and wheat yield. Thematic analysis was applied to qualitative interview transcripts to contextualize farmer perceptions and adoption barriers. The anticipated findings suggest that organic fertilizers—particularly poultry manure and vermicompost—significantly improve wheat yields by 20-35% relative to the control, while enhancing soil organic matter, nutrient availability, and microbial activity, thereby contributing to soil fertility and sustainability. These results are expected to demonstrate that organic fertilization is a viable alternative to chemical inputs, promoting environmentally sound agriculture. The study advances knowledge by providing empirical evidence on the specific impacts of different organic amendments on wheat productivity and soil biological properties within smallholder systems, grounded in the theoretical framework of the Soil Fertility and Sustainable Agriculture theories. It is projected that this research will inform policy-makers, extension agents, and farmers on best practices for integrating organic fertilizers into wheat cultivation, especially under resource-limited conditions, thereby fostering sustainable intensification. The main conclusion emphasizes that organic fertilization enhances both crop productivity and soil health, advocating for the adoption of organic amendments as part of integrated nutrient management strategies. Recommendations include promoting organic material use through training programs, developing locally adapted organic fertilizer formulations, and encouraging further longitudinal studies to assess long-term impacts. Overall, this research contributes to the growing body of sustainable agriculture literature and offers practical pathways toward resilient and environmentally sustainable wheat production systems.