This paper presents a global soil
moisture prediction method based on an average
cluster sampling strategy, using group samples uniformly extracted from regions with heterogeneous soil
moisture variation characteristics for training. Ensuring diversity in samples from different regions and uniformity in
sample selection helps to stably learn features during model training. Experiments were conducted on the LandBench dataset, using five different seeds for a 1-day global forecast. The results for each seed were averaged, and the results show that the proposed group sampling strategy outperforms several traditional LSTM-based models that do not adopt this strategy, with a median R 2 Improvements range from 2.36% to 4.31%, while improvements from KGE range from 1.95% to 3.16%. Furthermore, at high latitudes, especially in specific regions, the proposed strategy demonstrates significant improvements in explanatory power, with R² improvements exceeding 40%. This validates the effectiveness of the proposed sampling strategy and introduces a new training paradigm to enhance generalization capabilities for the
deep learning community.