Study on the change characters of black soil quality in Northeast China

The black soil region in northeast China has become one of the most important regions for cereal grain production, while soil degradation is increasingly serious with the gradual reclamation of black soil resource.This paper details the change characters of black soil quality, and analyses the natural and artificial factors of black soil degradation. The analytical results showed that the total change trend of black soil in northeast farmland was that the black soil layer attenuated, the quantity of organic matter decreased, and the nutrient balance of soil maladjusted. At the mean while soil physical properties of black soil deteriorated, the productivity reduced, most of high yield farmland became mid, low yield farmland, which heavily restricted the foodstuff production and the economic sustainable development of the northeast, even for the whole country.