The dataset of main grain land changes in China over 1985–2020

Continuous, Accurate, and detailed information on main grain land (MGL) areas is crucial for provisioning food security and making policies affecting sustainable agricultural production. Here, we developed the change map of MGL with resolution 30m in China for the period 1985–2020 using the Landsat image-based random forest algorithm on the GEE platform. Finally, the planting intensity, gain time and loss time of MGL was calculated. Results indicate that our mapping results are highly consistent with the annual planting area of various grain crops according to national statistics. The proportion of different MGL types in 2020 is presented as follows: single maize (38.55%) > single rice (23.23%) > single wheat (15.42%) > wheat & maize (12.60%) > double rice (7.65%) > wheat & rice (2.48%). Due to over half of MGL expansion occurring after 2000, the average planting intensity of MGL in China is 19.74 years in the past 36 years. The consistent, high-resolution data of MGL change can support progress toward sustainable agricultural management and food production.