增值尿素对小麦产量、氮肥利用率及肥料氮在土壤剖面中分布的影响

本研究利用同位素15N尿素，采用尿素熔融工艺分别制备了普通尿素（U）、 海藻酸增值尿素（AU）、 腐植酸增值尿素（HAU）和谷氨酸增值尿素（GU）试验产品，运用土柱栽培试验研究等氮量条件下（N 0.1 g/kg 干土，以030 cm土层干土重量计算）3种增值尿素产品对小麦产量、 氮肥利用率和肥料氮在土壤剖面中分布的影响。主要结果， 1）与U相比，AU、 HAU和GU处理均可显著提高小麦籽粒产量，增加幅度分别为7.12%、 13.63%和3.65%; 2）小麦吸收的氮素中有44.8%~48.0%来自肥料氮，AU、 HAU、 GU处理的小麦地上部吸收的肥料氮量均显著高于U处理，分别高出4.83%、 7.41% 和 3.12%; 3）虽然所有处理土壤残留的肥料氮均主要集中在050 cm土层中，U处理在5090 cm层次土壤肥料氮累积量显著高于AU和HAU处理; 4）AU、 HAU和GU处理的小麦氮肥表观利用率分别较U处理显著提高6.38、 15.63、 3.08个百分点，HAU和AU处理的15N利用率分别较普通尿素高出3.70和2.41个百分点，AU、 HAU和GU处理的肥料氮的损失率分别比普通尿素显著降低7.64、 9.52和2.19个百分点。

Effects of value-added urea on wheat yield and N use efficiency and the distribution of residual N in soil profiles

In this study,  three kinds of value-added urea  containing a certain ratio of: alginic acid,  humic aicd (HAU) and glutamic acid (GU),  were prepared with isotope¹⁵N urea using the urea melt technology. Pot experiments were conducted under the same N application rate (N 0.1 g/kg dry soil by the soil weight of 0-30 cm soil layer) to investigate the effects of value-added urea on wheat yields,  N use efficiencies and the distributions of fertilizer N in soil profiles. The results show that:  1) Compared with urea (U),  the grain yield of wheat  applied with alginic acid urea (AU),  humic acid urea (HAU) and glutamic acid urea (GU) are increased by 7.12%,  13.63% and 3.65% respectively. 2) The percentage of fertilizer N contribution in the total wheat N uptake ranges from 44.8%-48.0%,  the percentages with AU,  HAU and GU are  4.83%,  7.41% and 3.12% significantly higher than that with U. 3) The residual fertilizer N is mainly centralized in 0-50 cm soil layer with all the treatments, but the residual amounts  from U treatment is significantly higher than those from  AU and HAU  treatments  in 50-90 cm soil layer. 4) The percentages of fertilizer N apparent recoveries from AU,  HAU and GU are 6.38,  15.63 and 3.08 higher than that of the U treatment. The ¹⁵N recoveries of HAU and AU are significantly higher than that of the U treatment with increased percentage points of 3.70 and 2.41,  respectively. As a result,  the fertilizer nitrogen loss rates of AU,  HAU and GU are significantly lower than that of the U treatment with decrease of 7.64,  9.52 and 2.19 percentage points,  respectively.