ASSESSING THE LONG-TERM EFFECTS OF INTENSIVE MONOCULTURE ON SOIL MICROBIAL DIVERSITY AND NUTRIENT CYCLING IN SUBTROPICAL CROPPING SYSTEMS

Abstract

This study investigates the long-term ecological impacts of intensive monoculture farming in subtropical regions and evaluates the potential benefits of diversified agricultural practices. Through a mixed-methods approach, including soil nutrient analysis, microbial diversity profiling, and farmer perception surveys, we compared monoculture systems with diversified approaches such as intercropping, crop rotation, and cover cropping. Results revealed that monoculture practices significantly deteriorate soil quality, as indicated by reduced pH levels, lower organic carbon content, and diminished microbial diversity indices (Shannon and Simpson). Soil under diversified systems, in contrast, exhibited improved macronutrient levels (N, P, K), enriched microbial communities, and enhanced carbon sequestration. Farmer surveys confirmed greater concern regarding soil degradation and pest outbreaks under monoculture, with over 85% of monoculture farmers reporting ecological decline compared to only 25% in diversified systems. Yield trend analysis from 2020 to 2023 demonstrated a consistent decline in monoculture outputs, while diversified systems showed a progressive increase in productivity. Additionally, pest outbreaks were reported to be twice as frequent in monoculture fields. These findings substantiate the ecological superiority of diversification strategies, emphasizing their role in improving soil health, boosting resilience, and stabilizing yields. The study concludes that transitioning away from monoculture towards diversified agroecosystems is critical for long-term agricultural sustainability, and calls for policy interventions, farmer support programs, and education to facilitate this transformation in subtropical agriculture.