Assessing the Impact of Organic Mulching on Soil Health and Crop Yield

Thesis Abstract

The sustainability of crop production systems increasingly depends on soil management practices that enhance soil health and optimize yield outcomes, with organic mulching emerging as a promising technique to improve soil quality while reducing dependency on chemical inputs. Despite its widespread use among smallholder farmers, empirical evidence quantifying the specific impacts of organic mulching on soil biochemical and physical properties, as well as crop productivity, remains limited in regions characterized by variable climatic conditions and diverse cropping systems. This study aims to critically assess the effects of organic mulching on soil health parameters and crop yield, focusing on maize cultivation within temperate agricultural zones. The research specifically seeks to determine how different types of organic mulches—namely coconut husk, neem leaves, and rice straw—affect soil nutrient dynamics, microbial activity, moisture retention, and maize yield performance, thereby contributing to sustainable soil management strategies. The study employed a randomized complete block design (RCBD) with four treatments control (no mulch), coconut husk mulch, neem leaf mulch, and rice straw mulch, replicated across five blocks to ensure statistical robustness. The population comprised smallholder maize farmers within the study region, with twenty plots per treatment, totaling eighty experimental units. Data collection involved repeated soil sampling at three key maize growth stages vegetative, flowering, and maturity, to measure soil pH, organic carbon, nitrogen, phosphorus, and microbial biomass using standardized procedures, including Kjeldahl digestion and phospholipid fatty acid analysis. Crop yield data were obtained by harvesting and weighing maize grains from a designated 5 m² quadrat per plot. Additionally, soil moisture content was monitored weekly with tensiometers. To understand farmers' perceptions, qualitative data were gathered through focus group discussions, while the quantitative data were analyzed via Analysis of Variance (ANOVA) to identify significant differences among treatments, followed by Tukey's post hoc tests. Regression analysis was employed to explore relationships between soil health indicators and crop yield, and multivariate techniques such as principal component analysis (PCA) facilitated the identification of key soil variables influenced by mulching practices. The theoretical framework underpinning this study draws on the Soil Degradation and Sustainable Agriculture theories, complemented by the Ecological Intensification model, to elucidate how organic mulching enhances soil resilience and productivity. It is anticipated that the findings will demonstrate significant improvements in soil biochemical properties, microbial activity, and moisture retention levels in plots treated with organic mulches, especially coconut husk and neem leaves, relative to the control. These enhancements are expected to correlate positively with increased maize yields, verifying the hypothesis that organic mulching contributes substantially to sustainable crop production by restoring soil health. The research is expected to fill notable gaps in the literature regarding the comparative efficacy of different organic mulching materials within temperate farming contexts, offering nuanced insights into their practical application and effectiveness. Furthermore, the study aims to provide farmers, extension agents, and policymakers with evidence-based recommendations for adopting organic mulching techniques that optimize soil fertility, reduce input costs, and promote environmental sustainability. In conclusion, the study will assert that strategic application of specific organic mulches can significantly enhance soil health parameters and crop productivity, supporting the broader goal of sustainable agriculture. Recommendations will emphasize the importance of selecting appropriate mulch types tailored to local environmental conditions, integrating mulching into comprehensive soil fertility management plans, and advocating for further research into long-term effects and economic feasibility. This research will contribute to the advancement of agroecological practices and foster improved resilience of smallholder farming systems amidst environmental challenges.