Impact of Organic Mulching on Soil Health and Tomato Yield in Commercial Farms

Thesis Abstract

The depletion of soil nutrients and declining tomato yields due to conventional farming practices necessitate sustainable land management interventions in commercial agricultural systems. This study investigates the impact of organic mulching on soil health parameters and tomato productivity within a commercial farm setting, aiming to provide empirical evidence to inform best practices for sustainable tomato cultivation. The specific objectives include evaluating changes in soil physical and chemical properties attributable to organic mulching, quantifying variations in tomato yield across mulching treatments, and assessing farmers’ perceptions of mulching practices in relation to crop performance and soil management. Employing a mixed-methods research design, the study combines a randomized complete block experiment with qualitative farmer interviews. The target population comprises 120 commercial tomato farmers operating in the Green Valley agricultural zone. A stratified random sampling technique selected 60 farmers, who were divided equally into treatment and control groups. The treatment group applied organic mulches—specifically, composted cocoa husks—at a recommended rate of 5 tons per hectare, while the control group employed conventional bare-soil management. Data collection involved soil sampling at three different growth stages (vegetative, flowering, and harvest) and yield measurement per plot. Soil analysis utilized standard laboratory techniques, including pH, organic matter content via loss on ignition, macro- and micronutrient levels through atomic absorption spectroscopy, and soil bulk density. Tomato yields were measured by harvesting and weighing all fruits from designated plots. Farmer perceptions were captured through semi-structured interviews, with thematic analysis employed for qualitative data. Quantitative data were analyzed using ANOVA to test differences in soil properties and yield between treatments, with regression analysis exploring relationships between soil health indicators and crop yields. The study employed the Theory of Planned Behavior as a conceptual framework to interpret farmers’ adoption of mulching practices, complemented by descriptive statistics and post-hoc tests to ascertain the significance of effects. It is anticipated that organic mulching will significantly enhance soil organic matter, nutrient retention, and soil porosity, leading to improved tomato yields by at least 25% compared to the control. The analysis is expected to reveal correlative relationships between soil health improvements and productivity gains, confirming the role of organic mulching as a sustainable soil management practice. The findings contribute to knowledge by quantitatively establishing the efficacy of organic mulches, specifically cocoa husks, in improving soil fertility and crop yields within a tropical agricultural context. Additionally, the study elucidates farmers’ perceptions concerning the practicality, economic benefits, and challenges associated with organic mulching, thereby informing targeted extension interventions and policy frameworks. The research advances an integrated understanding of agronomic and socio-economic dimensions of sustainable soil fertility management. The main conclusion affirms that organic mulching constitutes a viable intervention for enhancing soil quality and increasing tomato yields in commercial farms. Based on the results, the study recommends the adoption of locally available organic residues, such as cocoa husks, as mulching materials, supported by capacity-building programs for farmers. Furthermore, it advocates for policy incentives to promote organic matter recycling and sustainable land management practices. Suggestions for further research include long-term investigations into the cumulative effects of organic mulching on soil health, assessments of economic viability under varying farm sizes, and exploration of different organic mulching materials suited to diverse agro-ecological zones. This study thereby offers a comprehensive evidence base for integrating organic mulching into sustainable tomato production systems, contributing to both agricultural productivity and soil conservation in tropical agricultural settings.