Abstract:

In order to understand the current situation of cotton stalks crushing and returning to the field for decomposition in Xinjiang, we took the returned cotton stalks and soil as the research objects to investigate the effect of cotton stalks returning to the field on the nutrient content of the soil in the soil layer of 0-30 cm. Soil samples were collected from 0-10, 10-20 and 20-30 cm in Tumushuke, Korla, Kuitun and Shihezi areas by field research method and five-point sampling method. The crushed length of cotton stalks in the field was 17%-18% at <10 cm, about 60% at 10-20 cm, and about 25% at >20 cm; the distribution of the length of cotton stalks in the depth of soil layer from 0 to 30 cm was 52% at <10 cm, 35% at 10-20 cm, and 13% at >20 cm; soil samples collected from 0-10, 10-20 and 20-30 cm of cotton fields were analyzed. The results showed that the soil moisture content of cotton fields in Tumushuke and Korla was 10%-18%, the organic matter was about 20 g/kg, and the quick-acting potassium was about 200 mg/kg; and that of cotton fields in Kuitun and Shihezi was 16%-20%, the organic matter was about 30 g/kg, and the quick-acting potassium was about 300 mg/kg. The highest quick-acting phosphorus was 181.44 mg/kg in Kuitun site and the lowest was 7.34 mg/kg in Korla, showing that the mean nutrient value in the southern border area was lower than that in the northern border. There are differences in the effects of returning cotton stalks to the field on soil properties in various regions, and these differences are not only affected by natural environmental factors, but also closely related to different grain sizes of cotton stalks, different burial depths and other factors. Cotton stalks crushed and returned to the field need to be adapted to local conditions, scientific return to the field.

Key words: Xinjiang, cotton straw crushing, cotton straw return to field, cotton straw decomposition, soil nutrients