Xinjiang cotton is mostly early-maturing, early-maturing and early-maturing varieties, and is not sensitive to light length response. It is a hi-light crop suitable for growing under sufficient light conditions. Both cotton light compensation points and light saturation points are high. According to the measurement, the light compensation point of a cotton single leaf is 750~1000lx, and the light saturation point is 7~80,000xx. Under normal circumstances, the suitable range of cotton leaves for light intensity is 8000~7000 lx. Under this range, the photosynthetic intensity increases with the increase of light intensity.
Moisture is an important component of cotton, and cotton needs to absorb water from the soil. The physiological water requirement requirements of cotton at each growth stage are sowing to emergence, the water content of 0~20 cm soil layer accounts for 70~80% of the field water holding capacity; in the seedling stage, the water content of 0~40 cm soil layer accounts for the water holding capacity of the field. 60 ~ 70% is suitable; in the early bud period, the water content of 0~60 cm soil layer accounts for 65~75% of the field water holding capacity; after the bud stage, the water content of 0~80 cm soil layer accounts for 70% of the field water holding capacity. ~80% is appropriate, not less than 60~65%; in the boll opening period, the relative water content of the soil is maintained at 55~70%. According to relevant research, about 2/3 of the cotton is consumed in transpiration throughout the growing period, and 1/3 is consumed in the evaporation of land.
The growth and development of cotton require water and nutrients, which are mainly obtained from the soil through the root system. The required temperature and air are taken from the soil and the mechanical support of the soil is required to grow. The physical and chemical properties of cotton soil and the biological properties of cotton fields largely restrict the yield and quality of cotton. Soil moisture, nutrients, temperature, air, saline content, texture and so on have a great impact on cotton growth.