Abstract: Crop straw returning to soil is one of the effective measures to improve soil physicochemical properties, enhance the activities of microorganisms and enzymes, and increase crop yield. It is one of the important ways of crop straw resource utilization. However, the straw returning to soil could lead to some negative impacts, such as decreasing germination rate of crops, increasing the occurrence of crop diseases and pests, and accumulation of soil heavy metals and other poisonous and harmful substances. The main way of crop straw returning to soil was the direct straw returning, while the indirect way of the crop straw returning to filed was composting. The decomposition rate and effect of the straw in soils mainly depended on the chemical composition of the straws (especially carbonnitrogen ratio), soil microbial status, soil temperature, and soil moisture. The future researches should focus on the methodologies of straw returning to soil, rapid decomposing agents and their application conditions, the impacts and control on the occurrence of crop diseases and pests of next season crops, the integration of agricultural machinery and agronomy, the ability to mitigate global change. Furthermore, we should improve methodologies and technologies related to straw returning to field and promote rapid application of crop straw returning to soil.

Key words: fiber quality, uptake and utilization of nutrient., Inner Mongolia west desert area, sowing date, yield, cotton