酸化沸石对尿素氮淋失和玉米籽粒氮素利用的影响

Effects of Acidified Zeolite on Urea Nitrogen Leaching and Nitrogen Utilization in Maize Kernel

在尿素减量施用条件下,探究添加酸化沸石(SF)对氮素淋失及籽粒氮肥利用率的影响。通过等温吸附试验,结合土柱淋溶和玉米盆栽试验,研究酸化沸石对NH_4^(+)—N和NO_3^(-)—N的吸附性能,以及不同施氮梯度下,酸化沸石对氮素淋失和氮肥利用率的影响,试验分别设置农民习惯施肥(CN)、氮肥减量15%(CN1)、氮肥减量30%(CN2)3个施氮梯度并分别添加土重0.2%的酸化沸石(CN+SF、CN1+SF、CN2+SF)。结果表明,酸化沸石对NH_4^(+)—N和NO_3^(-)—N的最大吸附量分别为25.44,31.59 mg/g,吸附过程可用Langmuir模型较好拟合。在减氮15%和30%时,添加酸化沸石,使NH_4^(+)—N累计淋失量较CN1、CN2分别降低7.10%,8.76%。在减氮30%时,酸化沸石可有效降低NO_3^(-)—N累计淋失量,较CN2处理减少15.90%。酸化沸石可有效提高土壤氮素含量和玉米籽粒氮肥利用率,添加酸化沸石(CN+SF、CN1+SF、CN2+SF)较单施尿素(CN、CN1、CN2)籽粒氮肥利用率分别提高10.37%,20.79%,47.14%。综上,酸化沸石在减施尿素条件下可有效降低土壤氮素淋失,提高玉米籽粒氮肥利用率,具有一定的农艺价值。

This study aims to investigate the effects of acidified zeolite(SF)on nitrogen leaching and nitrogen use efficiency of grain under the condition of urea reduction.The adsorption properties of acidified zeolite for NH_4^(+)—N and NO_3^(-)—N,and the effects of acidified zeolite on nitrogen leaching and nitrogen utilization under different nitrogen application gradients were studied by isothermal adsorption test,soil column leaching,and maize pot experiment.Three nitrogen reduction gradients were set up,i.e.,farmers’conventional fertilization(CN),nitrogen reduction by 15%(CN1),nitrogen reduction by 30%(CN2),and 0.2%acidified zeolite was added to the three nitrogen reduction gradients(CN+SF,CN1+SF,and CN2+SF),respectively.The results showed that the maximum adsorption capacities of NH_4^(+)—N and NO_3^(-)—N by acidified zeolite were 25.44 mg/g and 31.59 mg/g,respectively.The adsorption process could be well fitted by Langmuir model.When nitrogen was reduced by 15%and 30%,the cumulative leaching loss of NH_4^(+)—N with acidified zeolite was 7.10%and 8.76%lower than that of CN1 and CN2,respectively.Acidified zeolite could effectively adsorb NO_3^(-)—N only when nitrogen was reduced by 30%.The cumulative leaching loss of NO_3^(-)—N was 15.90%lower than that of CN2.The acidified zeolite could effectively improve soil nitrogen content and nitrogen use efficiency of maize grain.Compared with urea application(CN,CN1,and CN2),adding acidified zeolite(CN+SF,CN1+SF,CN2+SF)increased nitrogen use efficiency of grain by 10.37%,20.79%,and 47.14%,respectively.Under the condition of reducing the use of urea,acidified zeolite can effectively reduce soil nitrogen leaching,improve nitrogen use efficiency of maize,and has potential agronomic value.