Long-term observation dataset of soil nutrient in Qianyanzhou (1998–2022)

This data paper presents a long-term positioning observation dataset (1998–2022) for typical rice ecosystem in the Qianyanzhou region of Jiangxi Province, China. The dataset systematically encompasses soil nutrient data across different depths under three different tillage practices: conventional tillage, no-fertilization management, and straw incorporation. Soil profile samples from 0 to 100 cm depth were collected and subjected to laboratory analysis following the harvest of each cropping season. Core parameters include soil pH, soil organic matter (SOM), total nitrogen (TN), hydrolyzable nitrogen (HN), available phosphorus (AP), available potassium (AK), and slowly available potassium (SAK). Spanning 25 consecutive years, this dataset comprehensively covers a critical period encompassing China's agricultural modernization and significant climate change. This systematic, multi-layered, and long-term dataset provides a robust baseline for elucidating soil fertility trajectories in subtropical croplands, quantifying the long-term ecological effects of management practices, constructing regional soil-health assessment frameworks, calibrating agroecosystem carbon–nitrogen cycling models, and formulating adaptive management strategies under global change.