In situ study of ammonia volatilization from wheat cropland under long-term continuous fertilization

Enclosure growth chamber was used to collect and determine in situ ammonia volatilized from continuous wheat cultivation cropland based on a long-term fix position experiment.The obtained result showed that ammonia volatilized both in daytime and nighttime from cropland.The daily ammonia volatilization rate was 14.69±4.86 g/(ha·d) in booting,18.84±4.09 g/(ha·d) in filling,and 20.91±3.28 g/(ha·d) in ripening,respectively.The ammonia volatilization rate in daytime rapidly went up along with the lapse of growing stage of wheat.In the condition of single application N or P,ammonia volatilization rate increased sharply from filling stage,while that of M did not occure until ripening stage.Compared to M,N and P,formula fertilization could increase the ammonia volatilization rate in booting obviously;but in some degree it decreased volatilization rate in filling and ripening in daytime.The rate of ammonia volatilization in nighttime was lower than that in daytime with the growing of wheat,which is 57.34%±15.93% in booting,37.78%±17.84% in filling,and 13.73%±11.19% in ripening,respectively.Ammonia volatilization correlated with soil nutrient content to some extent.Effects of precipitation in filling on ammonia volatilization were different due to various fertilizers applied.