Optimizing Organic Fertilizer Application for Wheat Yield Enhancement

Thesis Abstract

The pervasive reliance on inorganic fertilizers in wheat cultivation has raised concerns regarding environmental sustainability, soil health deterioration, and declining crop productivity, prompting an urgent need to explore alternative nutrient management strategies. This study investigates the optimal application of organic fertilizers to enhance wheat yields, aiming to establish evidence-based guidelines that promote sustainable agricultural practices. The research specifically seeks to determine the most effective types and application rates of organic fertilizers, assess their impact on soil fertility parameters, and evaluate the resultant wheat biomass and grain yield. The overarching objective is to provide practical insights for farmers and agronomists striving to improve productivity while maintaining ecological balance. A mixed-methods research design was employed, integrating quantitative field experiments with qualitative farmer interviews. The study population comprised smallholder wheat farmers within the wheat-growing region of the Midwest wheat belt, totaling approximately 300 farmers. A stratified random sampling technique selected a representative sample of 120 farmers, divided into three treatment groups farmers applying recommended organic fertilizer rates, those practicing traditional organic applications, and a control group employing inorganic fertilizers. The experimental component involved establishing randomized complete block design (RCBD) field trials across four distinct sites to account for agro-ecological variability. Data collection instruments included standardized soil testing kits, crop growth measurement tools, and structured interview guides for farmer perceptions. Soil samples were analyzed in the laboratory using nutrient analysis techniques such as Kjeldahl method for nitrogen, flame photometry for potassium, and atomic absorption spectroscopy for micronutrients, to evaluate pre- and post-application nutrient levels. Wheat growth parameters (plant height, tiller number, and biomass) were recorded at key growth stages, while grain yield was measured at harvest. Data analysis involved descriptive statistics to summarize the soil and crop data, followed by inferential statistics including analysis of variance (ANOVA) to compare treatment effects on yield and soil fertility. Regression analysis was used to identify relationships between fertilizer application rates and yield outcomes. The study also employed the Theory of Planned Behavior as a framework to interpret farmers' adoption motivations and barriers, enriching the quantitative findings with qualitative insights. Expected results indicate that optimized organic fertilizer rates significantly improve soil nutrient profiles and wheat yields compared to traditional practices and inorganic fertilizer use. It is anticipated that the highest yields will be associated with a specific organic fertilizer application rate determined through dose-response analysis. This research anticipates revealing that organic fertilizers enhance soil microbial activity, leading to increased nutrient availability and crop resilience. The findings are expected to demonstrate that well-calibrated organic fertilizer use can substitute inorganic inputs effectively, reducing environmental footprint and promoting sustainable intensification. The study contributes to existing knowledge by providing empirical evidence on precise organic fertilizer management tailored for wheat cultivation, integrating agronomic, environmental, and socio-economic dimensions. By linking soil health improvements to yield gains, the research advances understanding of sustainable nutrient management practices suitable for smallholder systems. Additionally, it offers a theoretical model for fostering farmer adoption based on behavioral insights derived from the Theory of Planned Behavior. In conclusion, the findings will inform extension services, policymakers, and farmers about effective organic fertilizer regimes that optimize wheat productivity while conserving soil health and reducing environmental risks. The study recommends the development of context-specific guidelines for organic fertilizer application, capacity-building initiatives to promote adoption, and further research into long-term soil and yield effects. Ultimately, this work aims to contribute to resilient and sustainable wheat production systems through scientifically validated organic nutrient management strategies.