Assessing the Effect of Intensive Rice Monoculture on Land Degradation Under the SDG 15.3.1 Framework

Rice monoculture systems, often involving double- or triple-cropping cycles annually, require intensive agricultural practices that can lead to land degradation. This study evaluates land degradation within the long-term rice monoculture systems of Nakhon Sawan, Thailand, using the Sustainable Development Goal 15.3.1 framework. By focusing exclusively on persistent rice-growing areas, the study minimized the confounding signals of land-use conversion, allowing for an evaluation of the trajectories driven by combined agricultural management and climatic factors. The assessment integrated land use and land cover (LULC), soil organic carbon (SOC) stocks, and land productivity. Findings indicate that 83% of the original paddy area remained long-term monoculture, with LULC-related degradation limited to 4% of the original paddy cultivation area. While SOC depletion was observed in a few districts, a broader potential carbon accretion trend was identified across the province, likely driven by sustainable post-harvest practices such as stubble retention and organic amendments. Land productivity analysis revealed partial stress only in a few districts. The study demonstrated that long-term rice cultivation did not result in widespread deterioration of soil health on an aggregate provincial scale; however, district-localized degradation hotspots suffering from soil organic carbon depletion and climate-induced productivity stress were identified, demanding targeted regional management.