氮磷配施的氨挥发规律及机理研究

[目的]探讨氮磷配施的氨挥发规律及机理。[方法]设置5个施磷水平,通过大田试验、盆栽试验和土壤培养试验,研究氮磷配施的氨挥发规律。[结果]磷作基肥氮作追肥时,不同施磷处理的氨挥发速率先从低到高逐渐增至峰值,然后降低,峰值随施磷量增加而增高,最高峰值为2.36 kg/(hm2.d);追施氮肥3、7、12 d后,随着施磷量的增加,土壤中铵态氮含量增加,氨挥发强度增强;土壤脲酶活性比氮磷同为基肥时增强,随施磷量增加呈明显增加趋势。氮磷同为基肥时,单施氮处理不施磷处理的土壤脲酶活性比氮磷同施处理高,随着施磷量的增加,氮磷同施处理的脲酶活性略有增加趋势。[结论]土壤铵态氮含量与氨挥发速率、土壤脲酶活性均有较好的相关性。

Study an the Rule and Mechanism of Ammonia Volatilization of Combined Application of Nitrogen and Phosphorus

[Objective] The study was to explore the rule and mechanism of ammonia volatilization of combined application of nitrogen and phosphorus.[Method] Through field,pot and soil experiments,5 levels of P application were designed to study the rule and mechanism of ammonia volatilization of combined application of nitrogen and phosphorus.[Result] When P fertilizer was taken as basal fertilizer and N fertilizer as top dressing,the rates of ammonia volatilization in different P treatments were first increased up to the peak value from low to high and then was decreased;the peak value was increased with the increment of P application rate with highest peak value of 2.36 kg/(hm2·d);after N was applied as top dressing for 3,7,12 d later,the content of ammonium nitrogen in soil was increased and the intensity of ammonia volatilization was also increased with the increment of P application rate;the activity of urea enzyme in soil was higher than in the treatment with N and P as basal fertilizers together and was increased obviously with the increment of P application rate.When N and P were applied as basal fertilizers together,the activity of urea enzyme in soil in the treatment with N application alone(no P application) was higher than that in the treatment with N and P application together.With increment of P application rate,the activity of urea enzyme had a tread of small increase.[Conclusion] The content of ammonium nitrogen in soil had a better correlation with the rate of ammonia volatilization and the activity of urea enzyme in soil.