What conditions are needed for cotton cultivation?
SummaryLight conditions: Cotton is suitable for growing under sufficient light conditions. Moisture conditions: The water requirement differs at each growth stage, so the amount of water applied needs to be reasonably controlled. Soil conditions: Cotton mainly obtains water and nutrients from the soil through its root system, so ensuring sufficient soil nutrients can improve the quality and yield of cotton. Heat conditions: The suitable growth temperature at the seedling stage is around 20°C, and heat conditions will affect the emergence time of cotton.
1. Light conditions
Cotton is a light-loving crop and is suitable for growing under relatively sufficient light conditions. Both its light saturation point and light compensation point are very high. Testing has shown that the light saturation point of a single cotton leaf is 70000-80000 lux, and the light compensation point is 750-1000 lux. Under normal circumstances, the suitable range of light intensity for cotton leaves is 8000-70000 lux.
2. Moisture conditions
The water requirement of cotton also differs at different growth stages. According to statistics, during the entire growth process of cotton, about 1/3 of the water is consumed by soil evaporation, and 2/3 is consumed by transpiration.
1. From sowing to emergence, the soil moisture content in the 0-20cm layer should mainly be 70-80% of field capacity.
2. At the seedling stage, the soil moisture content in the 0-40cm layer should mainly be 60-70% of field capacity.
3. At the squaring stage, the soil moisture content in the 0-60cm layer should mainly be 65-75% of field capacity.
4. At the peak squaring stage, the soil moisture content in the 0-80cm layer should mainly be 70-80% of field capacity, and should not fall below 60-65%.
5. At the boll-opening stage, the soil moisture content needs to be maintained at 55-70%.
3. Soil conditions
To ensure robust growth of cotton, sufficient water and nutrients are needed. These are mainly obtained from the soil through the root system, and part of the required temperature and air also comes from the soil. During planting, mechanical support from the soil is needed for robust growth. Soil temperature, air, moisture, nutrients, salinity and alkalinity content, and texture will all affect the quality and yield of cotton.
4. Heat conditions
(1) In the early and late stages of cotton growth, it is particularly sensitive to heat conditions. From sowing to emergence generally takes 7-20 days, during which the active accumulated temperature required is 160-320°C. When the temperature remains stable above 20°C after sowing, emergence can occur after 7-8 days.
(2) If the temperature after sowing is unstable and remains at an average of 15-17°C, it generally takes 20 days for emergence. The lower the average daily temperature, the more accumulated temperature is needed from sowing to emergence. From flowering to boll opening, heat conditions will not only affect the quality of cotton, but in severe cases will also lead to a decline in cotton yield.