华北平原小麦季氮肥氨挥发损失及影响因素研究

试验采用间歇式密闭室通气法,测定了冬小麦生长季氨挥发的损失量。结果表明:冬小麦施用氮肥后氨挥发速率升高,高峰期持续时间较短,基肥与追肥后氨挥发速率最大分别达到1.12 kg/(hm2.d)和0.66 kg/(hm2.d),可见冬小麦基肥氨挥发损失高于追肥。从整个生长季节来看,冬小麦不施氮和每公顷施氮75,150,225,300 kg小区的累计挥发量分别为5.25,5.97,7.22,9.31,12.85 kg/hm2;冬小麦生长季节来自氮肥的氨挥发为0.72,1.97,4.07,7.61 kg/hm2,占施氮总量的1.0%,1.3%,1.8%,4.2%。当氮施用量超过150 kg/hm2时,由于氨挥发增加将使农田氮损失显著提高,通过Elovich动力学方程(y=a+blnt)对时间和氨挥发量进行拟合。土壤0~10 cm NH4+-N含量和氨挥发量之间具有显著的相关性。而温度是氨挥发的重要影响因素。

Ammonia volatilization of N fertilizer and influencing factors in the North China Plain

This paper aims to study the ammonia volatilization use continuous air flow enclosure method in wheat season.Results show that application of the basal caused the evaporation rate 1.12 kg/(hm2·d) of ammonia to increase rapidly in short time;in jointing of wheat the top-dressing rate 0.66 kg/(hm2·d) of ammonia volatility was low without any peak value.In light of Elovich's dynamic equation(y=a+blnt) to fitting between the time and amount of ammonia volatilization,the results showed that loss of ammonia volatilization of the basal was higher than the top-dressing.In the whole growing season of wheat,the experiment set five treatments: 0,75,150,225,300 N kg/hm2,the cumulative loss amount of their ammonia volatilization were 5.25,5.97,7.22,9.31,12.85 kg N/hm2 respectively;Loss of N fertilizer was 1.0%,1.3%,1.8%,4.2% respectively.And the amount of ammonia volatilization cannot be ignored for loss of N,when N fertilizer was applied more than 150 kg N/hm2.Effect of temperature is important to amount of ammonia volatilization.