Fig. 1. Soil health evaluation for farmland in Fangzheng county, Heilongjiang Province, China. A, Regression analysis of soil health index (SHI) of paddy and dryland soils derived from minimum dataset (MDS) and total data set (TDS), as well as their correlation with rice yield. B and C, SHI (B) and the proportion (C) of paddy and dryland soils falling into different health categories. D and E, Soil single-function indices (D), and their factor loadings and weights (E) of paddy and dryland soils. Bi, Biological function; En, Environmental function; Ec, Ecological function; Qu, Quality function. F, Relative importance of each MDS indicator in soil health evaluation determined by the random forest model. MSE, Mean squared error; FS, Fungal Shannon diversity; BOF, Bacterial observed features; CLT, Cultivated-layer thickness; βG, β-1,4-glucosidase; SOM, Soil organic matter; AK, Available potassium; LAP, Leucine aminopeptidase; NO3--N, Nitrate nitrogen; αG, α-Glucosidase; CEC, Cation exchange capacity; AP, Available phosphorus; MBC, Microbial biomass carbon; BS, Bacterial Shannon diversity; BD, Bulk density; NH4+-N, Ammonium nitrogen.