In situ determination of ammonia volatilization in field of North China

By the double-layer-sponge-trapping method rectified,the ammonia volatilization was measured after applying different nitrogen fertilizers or those with phosphor or potassium fertilizer.The results show that ammonia volatilization is affected greatly by the application method of N fertilizer,temperature of soil and irrigation.The loss of ammonia volatilization is in a range from 0.67 to 9.91 kg/hm²,accounting for 0.41%～5.0% of total N amount applied,of which the majority occurs in summer maize seasons（above 80%）.Ammonia volatilization is reduced greatly when the urea is mixed with TCP,while it does not change obviously after adding potassium fertilizer.