Why is the fertilizer effect of ammonium bicarbonate better than urea in winter and spring?

Why is urea fertilizer ineffective in winter and spring? Why use ammonium bicarbonate instead of urea in winter and spring? Please understand the netizens to introduce. Urea is a kind of high concentration nitrogen fertilizer, which belongs to neutral quick-acting fertilizer, and can also be used to produce a variety of compound fertilizers. Urea is the most common and the largest variety of nitrogen fertilizer, so that urea is often used as base fertilizer or topdressing fertilizer even at low temperature in winter or early spring. In fact, this practice of applying urea in different seasons is unscientific. Although ammonium bicarbonate is easy to volatilize under the condition of high temperature, the application of ammonium bicarbonate is better than urea at low temperature in winter and spring. The reason is that ammonium bicarbonate has a faster fertilizer effect than urea. Because after urea is applied into the soil, it can not be directly absorbed by crops, but must be converted from amide nitrogen to ammonium nitrogen before it can be used. Its transformation rate is proportional to temperature and is very slow at low temperature. According to the experiment, under the condition of 10 ℃, the conversion of urea takes 10 days, and ammonium bicarbonate can decompose even if it is less than 5 ℃. Therefore, after the application of ammonium bicarbonate at low temperature, it can still be quickly absorbed and utilized by crops. At the same time, the loss of urea is greater than that of ammonium bicarbonate. Ammonium bicarbonate rarely volatilizes when the air temperature is lower than 20 ℃. After being applied to the soil, ammonium bicarbonate and carbonate ions are firmly absorbed by soil colloids, and then slowly released for crop absorption and utilization. Its adsorption capacity is about 8 times that of urea, and its volatilization loss is only 1/3 of that of urea at low temperature. Less nutrient loss. On the contrary, after urea was applied to low temperature soil, it was dissolved in soil solution in molecular state because it was difficult to transform, and could not be absorbed by soil colloid, so it was easy to be leached by irrigation water or Rain Water, resulting in the loss of nitrogen nutrients. It has been tested that the effect of topdressing ammonium bicarbonate in winter wheat field is 1-1.5 times higher than that in high temperature season. In this farming network, netizens are advised to apply ammonium bicarbonate to crops in winter and spring and leave urea in the hot season. Ammonium bicarbonate is applied under the condition of low temperature, no matter as base fertilizer or topdressing fertilizer, the deep application of 10 cm is better, the fertilizer utilization efficiency is high, and the effect of increasing yield is remarkable.