Comparative Analysis of Organic and Conventional Fertilizer Effects on Crop Yield and Quality

Thesis Abstract

This study investigates the comparative effects of organic and conventional fertilizers on crop yield and quality within the context of increasing demands for sustainable agricultural practices and food security. The rise in the adoption of organic farming practices has prompted a critical examination of their efficacy relative to conventional methods, particularly regarding productivity and nutritional value. Despite numerous studies, there remains limited comprehensive analysis combining agronomic performance, economic viability, and quality attributes across different cropping systems, which this research aims to address. The core objective is to evaluate and compare the influence of organically and conventionally fertilized systems on the quantitative and qualitative aspects of maize (Zea mays) production over two planting seasons. Specifically, the study aims to (1) assess crop yield differences under organic versus conventional fertilization regimes, (2) analyze variations in key quality parameters including protein content, mineral composition, and antioxidant levels, (3) determine the economic efficiency of both fertilization methods, and (4) identify environmental implications associated with each approach. The research adopts an experimental research design with a randomized complete block design (RCBD) implemented across three agricultural sites representative of typical maize cultivation zones. The population comprises smallholder farmers and experimental plots totaling 18 plots (6 per site), with 9 plots assigned to organic fertilization and 9 to conventional fertilization, coded to prevent bias. Data collection involves quantitative measurements of crop yield (kg/ha), laboratory analyses of crop nutrient content, and economic assessments via input-output analysis. Fertilizer application rates and schedules follow best practices documented in regional agricultural extension manuals, with organic amendments including compost and manure, and conventional fertilizers employing synthetic NPK formulations. Data validity is ensured through calibration of measurement instruments and standardized laboratory protocols, while reliability is established through repeated measures across seasons. Data analysis involves descriptive statistics for initial characterization, followed by inferential statistical methods such as analysis of variance (ANOVA) to evaluate treatment effects on yield and quality parameters. Multiple regression analyses explore relationships between fertilizer type, crop performance, and environmental indicators, grounded in the Theory of Planned Behavior to interpret farmers' decision-making processes regarding fertilizer adoption and sustainability. The study’s expected findings include statistically significant differences in crop yield and nutritional quality favoring or disfavoring either fertilization method, as well as insights into the economic costs and environmental impacts, such as soil health indicators, of both approaches. This research contributes to the existing body of knowledge by providing a holistic, empirically grounded comparison of organic and conventional fertilization systems in maize cultivation, integrating agronomic, economic, and environmental dimensions. It aims to fill gaps related to contextualized empirical evidence necessary for policy formulation and extension service optimization tailored toward sustainable intensification. The findings are anticipated to inform best practices and support decision-making among farmers, extension agents, and policymakers fostering sustainable agricultural development. The conclusion underscores that while both fertilization approaches have merits, organic systems may offer comparable yields with added soil health benefits, whereas conventional systems may dominate in initial productivity metrics. Recommendations include promoting integrated fertilization strategies, enhancing organic input accessibility, and further longitudinal studies to monitor long-term impacts. Future research should explore crop diversification, socio-economic influences, and climate resilience to deepen understanding of sustainable fertilization practices in diverse agro-ecological contexts.