Alfisols are important soils in China. They occupy about 1.25 million km2, or about 13% of the land area. In the current Chinese system of soil classification, burozem, yellow-brown earths, Baijiang (Planosol) soils and parts of drab soils. They are mostly forested soils with an estimated 5–13 t/ha · yr of organic matter returned to the soils from temperate mixed conifer and broad-leaved forest. In terms of elemental bio-cycling, Ca is prominent.