Some fertilizers can be directly absorbed by crops after being applied to the soil, while others cannot. Increased application of phosphorus and zinc fertilizers can effectively enhance the freezing resistance of plants. Therefore, it is necessary to make full use of natural conditions and fertilize scientifically according to the characteristics of fertilizers. Do not fertilize blindly and affect crop growth. So how to fertilize in cold weather?
Ammonium bicarbonate should be applied. Ammonium bicarbonate is not easy to volatilize and decompose when the temperature is low, which is beneficial to improve fertilizer utilization. Ammonium bicarbonate belongs to ammonium nitrogen fertilizer, which can be directly absorbed and utilized by crops after being applied to the soil. It has fast fertilizer effect and is a typical "quick fertilizer". It can provide nitrogen nutrition for crops in time. Someone has done an experiment. The effect of topdressing ammonium bicarbonate in wheat fields during cold and snowy weather is 1-1.5 times higher than that in high temperature seasons.
Avoid applying urea. Urea belongs to acylammonium nitrogen fertilizer and cannot be directly absorbed and utilized by crops after being applied to the soil. It needs to be converted into ammonium nitrogen under the action of urease secreted by urea bacteria in the soil to be absorbed by roots. The speed of urea conversion mainly depends on the soil temperature at the time. Under normal circumstances, all urea applied to the soil is converted into ammonium nitrogen. It takes 7-10 days when the ground temperature is 10°C, and 4-5 days at 20°C. It only takes 2-3 days at 30°C. If urea is applied, it will affect the growth of crops because the fertilizer effect is slow.
Increase the application of phosphorus and zinc fertilizers. The absorption of phosphorus and zinc by crops is significantly affected by temperature and light. In autumn and winter, low temperature and insufficient light can easily induce phosphorus and zinc deficiency in overwintering crops. Phosphate and zinc fertilizers should be properly applied. In addition, phosphorus can enhance the cold resistance of plants, and increased application of phosphorus fertilizer is also beneficial to prevent crops from freezing.