纳米碳增效尿素对水稻田面水氮素流失及氮肥利用率的影响

Effects of NMUrea on nitrogen runoff losses of surface water and nitrogen fertilizer efficiency in paddy feild

为了探讨纳米碳增效尿素对水稻田面水氮素流失特征及肥料利用率的影响,以普通尿素处理为对照,对水稻田面水氮素浓度、氮素径流流失特征、产量及氮肥利用率进行了试验研究。结果表明,施用氮肥后,田面水全氮浓度迅速增加,且施氮量越高,田面水全氮浓度越大。纳米碳增效尿素处理与普通尿素处理比较,其田面水全氮浓度下降速度较快,氮素随排水流失风险期短。应用对数方程模型预测,纳米碳增效尿素田面水安全排放期为施肥后11.5～15.9d,普通尿素田面水安全排放期为施肥后12.5～17.3d,纳米碳增效尿素处理与普通尿素处理比较,其遇雨引起氮素流失期限缩短1.0～1.5d。该研究同时得出,总氮素径流流失量随施氮量的增加而增加,相同施氮量的两肥料处理间比较,纳米碳增效尿素处理氮素随降水流失量显著小于普通尿素处理,仅为普通尿素的70.6%～74.3%。该研究进一步表明,纳米碳增效尿素处理籽粒产量、氮肥农学利用率亦显著大于普通尿素处理,产量最大提高幅度达10.2%,氮肥农学利用率最大提高幅度达44.5%。总之,与普通尿素处理比较,纳米碳增效尿素处理遇雨引起氮素流失期限缩短、氮素径流流失量小,产量、氮肥农学利用率均较高,是优于普通尿素的新型高效肥料,其中施氮量为225kg/hm2的处理,是该试验条件下的氮肥运筹的高产、高效、安全模式。

To elucidate the effects of NMUrea on the N runoff losses characteristics and nitrogen use efficiency,the experiment was carried out and the nitrogen concentration,nitrogen runoff losses character,and grain yield were studied,with common Urea as control（CK）. The results showed that total nitrogen （TN） concentration increased sharply after nitrogen fertilizer application. At the same nitrogen rate,the TN concentration in the NMUrea treatments decreased significantly faster than those of the normal Urea. Based on a logarithm model,the safe drainage time was 11.5-15.9 d after nitrogen application for NMUrea and 12.5-17.3 d after nitrogen application for Urea,respectively. The amount of N loss from drainage increased with the increase of nitrogen fertilizer rate. At the same N fertilizer rate,N loss in NMUrea treatment was less than that in the Urea treatment,and that was 70.6%-74.3% of Urea＇s. It was also indicated that grain yield and N agronomic efficiency of NMUrea treatment were higher than those of Urea treatments. On the above basis,it was concluded that NMUrea treatments gained higher grain yield and N agronomic efficiency,and lower N loss compared with the normal Urea treatments. The treatment with 225 kg/hm2 NMUrea-N was recommended as the best rate for achieving high-yield,high-N efficiency and safe cultivation technique in hybrid rice.