缓释氮肥施用比例对冬小麦产量及氮肥利用效率的影响

Effects of slow-release nitrogen fertilizer application ratio on yield and nitrogen fertilizer utilization efficiency of winter wheat

针对陕西关中小麦肥料利用效率不高的问题,在陕西省杨凌示范区开展了缓释氮肥与尿素的配施试验,设置了不施氮肥(N0)、100%尿素(N1)和4个不同缓释氮肥配施处理(N2(100%)、N3(25%)、N4(50%)、N5(75%)),以不施肥CK为对照;分析缓释氮肥与尿素配施对冬小麦干物质累积及氮素吸收量、土壤硝态氮含量和分布、产量及水氮利用效率的影响。结果表明:与N1、N2处理相比,缓释氮肥和尿素配施不仅能显著增加冬小麦干物质累积量(4.69%~11.40%)、氮素吸收量(5.92%~24.08%)及产量(6.00%~22.41%),还能增加土壤表层(0~40 cm)的硝态氮累积量(2.09%~45.51%),减少其淋失到深层土壤,提升氮肥利用效率。N5处理下冬小麦的氮肥偏生产力(42.46 kg/kg)、氮肥农学利用率(15.46 kg/kg)和氮肥表观利用率(47.79%)均最大,成熟期N5处理的干物质累积量较N1和N2处理分别提高了11.40%和9.20%,地上部氮素累积量分别提高了24.08%和11.49%,产量分别提高了22.41%和11.00%。收获时N5处理0~40 cm土层中硝态氮的累积量最大,比其它施肥处理提高了1.30%~19.52%。综上所述,75%缓释氮肥+25%尿素处理(N5)是本研究中冬小麦高产高效的最优施肥方案。

Considering the low fertilizer utilization efficiency in Guanzhong,Shaanxi Province,the experiment for the combined application of slow-release nitrogen fertilizer and urea was carried out in Yangling,Shaanxi Province.Different combinations was set,namely,N0(non-nitrogen fertilizer),N1(100%urea),and four different fertilizer dosages including N2(100%slow-release nitrogen fertilizer),N3(25%slow-release nitrogen fertilizer+75%urea),N4(50%slow-release nitrogen fertilizer+50%urea),N5(75%slow-release nitrogen fertilizer+25%urea),and the non-fertilization CK was used as the control.Subsequently,effects of the combined application of slow-release nitrogen fertilizer and urea on dry matter accumulation and nitrogen absorption of winter wheat,soil nitrate content and distribution,yield and utilization efficiency of water and nitrogen were analyzed.According to the results,compared with N1 and N2 treatments the combined application of slow-release nitrogen fertilizer and urea not only can significantly increase the dry matter accumulation(4.69%-11.40%),nitrogen absorption(5.92%-24.08%)and yield of winter wheat(6.00%-22.41%),but also can enhance the content of nitrate nitrogen(2.09%-45.51%)in the surface soil(0-40 cm),reduce its leaching to the deep soil and finally improve the nitrogen utilization efficiency.In addition,in N5 treatment,the partial productivity of nitrogen fertilizer(42.46 kg/kg),agronomic utilization rate of nitrogen fertilizer(15.46 kg/kg),as well as the apparent utilization rate of nitrogen fertilizer(47.79%)of winter wheat were the highest.Moreover,compared with N1 and N2 treatments,the dry matter accumulation of N5 treatment increased by 11.40%and 9.20%,the above ground nitrogen accumulation increased by 24.08%and 11.49%and the yield increased by 22.41%and 11.00%,respectively.The residual amount of nitrate nitrogen in the N5 treatment of 0-40 cm soil layer was the largest at harvest time,which was increased by 1.30%-19.52%compared with other fertilization treatments.To sum up,the combination of 75%slow-release nitrogen fertilizer and 25%urea treatment is the best fertilization scheme for high yield and high fertilizer utilization efficiency of winter wheat.