Sugarcane Land Quality Evaluation and Limiting Factors Diagnosis in Typical Acidified Regions of Southern China Based on Minimum Data Set

Effective evaluation of cultivated land quality (CLQ) and limiting factors diagnosis is essential for sustainable land use and soil improvement. Studies on CLQ evaluation and limiting factors diagnosis have mainly focused on staple crops. However, related studies for sugarcane land at local scales remain relatively scarce. This study selected Xingbin District in Guangxi Zhuang Autonomous Region, a typical sugarcane-producing area, as a case study. A minimum data set (MDS) was constructed using principal component analysis to evaluate CLQ and an integrated approach combining membership functions, and bivariate Moran’s I was applied to identify limiting factors. Eight indicators, including soil pH, soil organic matter (SOM), available phosphorus, cultivated layer thickness (CLTH), cultivated layer texture, depth of obstacle horizon (DOH), topographic position, and biodiversity, were selected from the total data set (TDS) to construct the MDS. The CLQ derived from the MDS was strongly correlated with that from the TDS, indicating that the MDS can substitute for the TDS. CLQ in Xingbin District was classified into three grades, with moderate-quality land accounting for 84.7% of the whole study area. Soil pH, SOM, CLTH, and DOH were the main limiting factors for low-quality land, whereas pH and SOM dominated in moderate- and high-quality land. Bivariate Moran’s I revealed significant positive spatial autocorrelation between CLQ and CLTH, pH, and SOM. High–high clusters were mainly in the northeast, while low–low clusters were concentrated in the southwest. These findings provide scientific guidance for targeted soil management and sustainable sugarcane production.