聚丙烯酰胺对盐渍化土壤氮素的影响

Influence of PAM on Nitrogen of Salinized Soil

为了研究河套地区盐渍化土壤施用聚丙烯酰胺(PAM)后葵花全生育期内土壤氮素的时空变化规律及其利用率,采用正交试验对葵花生育期内0—100cm土层土壤碱解氮的动态变化规律及氮肥利用率进行分析。结果表明:施用PAM处理的盐渍化土壤在PAM施用层能够保持一定的碱解氮且不易使碱解氮下移,未施PAM的4个灌水处理在不同程度上均下移至40cm左右,表明施用PAM明显抑制了氮素深层移动效应。通过正交试验处理及SPSS主效应分析选取三因素最优的适用量为:水量1 800m3/hm2,氮素168kg/hm2,PAM量为18.75kg/hm2,并且PAM施用对中度盐渍化土壤氮肥利用率的影响显著。研究结果可为河套灌区盐渍化土壤合理施氮量及施用PAM对氮肥利用率的影响提供理论依据。

In order to study the temporal and spatial changes of nitrogen and its utilization after applying Poly- acrylamide（PAM） in soil salinization of area in Hetao during the whole sunflower growth period, we used the orthogonal experiment to analyze the dynamic change rule of alkali hydrolysable nitrogen and utilization rate of nitrogen in 0--100 cm soil depth during the sunflower growth. The results show that application of PAM could keep certain alkali hydrolysable nitrogen and limit the alkaline hydrolysis nitrogen to move down- wards in the PAM application layer of the soil salinization, in the 4 irrigation treatments without applying PAM, alkali hydrolyzabie nitrogen moved downward to about 40 cm at different degrees, indicating that application of PAM had the obviously restraining effect on nitrogen movement, and controlled nitrogen leac- hing, prevented soil barren. Through the analysis of the utilization rate of fertilizer and orthogonal experi- ment and main effect analysis of SPSS, the selected three optimum factor quantities are following： water is 1 800 m3/hm^2 , nitrogen is 168 kg/hm^2 , PAM is 18.75 kg/hm^2 , and application of PAM has the significant influence on utilization rate of nitrogen fertilizer in moderate salinized soil. The research results can provide the theoretical basis for using reasonable amount of nitrogen application and improving the application of PAM on utilization rate of nitrogen in salinization soil of irrigation area of Hetao.