施肥深度、灌水条件和氨挥发监测方法对氮肥氨挥发特征的影响

【目的】研究施肥深度、灌水条件和氨挥发监测方法对土壤氮肥氨挥发损失特征的影响,为评估田间原位监测试验结果提供依据。【方法】通过微区试验模拟大田基肥和追肥氨挥发条件。【结果】(1)在轻度盐渍化土壤上,氨挥发速率和损失累积量随着施肥深度的增加而降低,氮肥深施土壤10 cm氨挥发降低到施氮量2%以下,可有效控制氮肥氨挥发损失;氨挥发持续时间随着施肥深度的增加而缩短。(2)施肥后延迟灌水情况下,初始含水量高的土壤比含水量低的土壤氨挥发损失大;在同等条件下,延迟灌水会增加氮肥氨挥发损失;随着灌水量的增加,氨挥发损失降低;(3)3种氨气吸收方法比较结果显示,密闭法检测值远低于抽气法和通气法;在试验区域和试验条件下,抽气法和通气法监测结果较为接近。【结论】施肥深度和灌水条件是否与当地大田操作一致,是氨挥发测定值能否反映田间真实值的关键;三种监测方法对氨挥发田间原位监测是系统影响,密闭法结果偏低,抽气法是否反映田间真实值与抽气速率相关;通气法不需动力,可适用于田间多处理试验。

Influence of the Fertilization Depth,Irrigation and the Ammonia Volatilization Monitoring Method on Ammonia Volatilization Characters of Nitrogen Fertilizer

【Objective and Method】The aim of this text was mainly to study the effect of the fertilizer depth, irrigation and the ammonia volatilization monitoring method on the loss of ammonia volatilization characters of nitrogen fertilizer and provide basis for evaluating results of field in-situ monitoring test.【Result】(1) On the light saline soil,ammonia volatilization rate and loss cumulation were decrease with increase of fertilization depth,ammonia volatilization decreased to below 2% of nitrogen rate when nitrogen was applied to depth of 10 cm of soil,which could effectively control loss of ammonia volatilization of nitrogen;the duration of ammonia volatilization shorten with increase of fertilization depth;(2) Under postponing irrigation condition after fertilization,the ammonia volatilization loss of the high initial water content soil was greater than that of low initial water content soil;and under the equal conditions,the postponing irrigation could increase loss of ammonia volatilization of nitrogen;and the loss of ammonia volatilization decreased with increase of irrigation amount;(3) The results of comparison of three methods of ammonia gas absorption showed that detection value of enclosure method was lower than that of air exhaust method and venting method;Under this test area and conditions,the monitoring results of air exhaust method were close to each other.【Conclusion】Whether the fertilization depth and the irrigation whether were consistent with local field operation,which was the key of ammonia volatilization measured value whether reflected the field true value;the monitoring method had systematic influence on ammonia volatilization in field in-situ monitoring,results of enclosure method were on the low side,and whether the air exhaust method reflected the field true value was correlated with pumping speed;and the venting method need not dynamic,which was suitable for field multiprocessing experiment.