不同施氮方式对向日葵氮肥利用效率的影响

Nitrogen Use Efficiency of Sunflower is Affected by N-Fertilizer Applications

传统撒施肥料方式氮素易于挥发,肥料利用效率不高。【目的】提高河套灌区肥料利用效率。【方法】设置了不施肥(CK1)、仅撒施基肥(CK2)、撒施肥(SF)、穴施肥(XF)和沟施肥(GF)共5个田间试验处理,探索不同施肥方式下土壤硝态氮、铵态氮在不同生育期的变化特征以及不同施肥方式对向日葵产量、水肥利用效率的影响。【结果】不同施氮方式下,土壤中硝态氮和铵态氮量均随土壤深度的增加而降低。撒施处理的硝态氮和铵态氮主要集中在0~20 cm土层,而穴施和沟施处理下的硝态氮和铵态氮主要分布在0~40 cm土层。在施肥后20 d内,穴施和沟施处理下硝态氮和铵态氮量峰值早于撒施处理,其中穴施处理硝态氮和铵态氮量分别在施氮后第10 d和第5 d达到最大值(93.85 mg/kg和47.6 mg/kg);沟施处理硝态氮和铵态氮量均于施氮后第10天达到最大值(103.95 mg/kg和48.4mg/kg),而撒施处理硝态氮和铵态氮量则在第20 d和第10 d达到最大值(78.5 mg/kg和36.9 mg/kg)。穴施和沟施处理植株吸氮量、籽粒吸氮量、氮肥利用率和氮收获指数显著高于撒施处理,其中穴施处理氮收获指数较撒施处理高11.5%,比不施肥和仅施基肥氮收获指数高33.2%和27.2%。穴施处理向日葵产量和增产率明显高于撒施处理,同时,穴施处理和沟施处理的水分利用效率较高,与撒施处理差异显著。【结论】综合氮肥利用率、氮收获指数、氮肥偏生产力和氮肥农学效率等指标,在河套地区采用穴施肥处理有利于提高向日葵产量和氮肥利用效率。

【Objective】 Producing more from less has been mandated in developing sustainable agriculture in China and improving fertilizer use efficiency is essential to achieve this ambition. The purpose of this paper is to experimentally investigate how to reduce nitrogen loss caused by leaching and denitrification commonly seen in broadcast-fertilizer-application by taking sunflower in Hetao Irrigation District as an example.【Method】 We examined five treatments： No fertilizer（CK1）, base application（CK2）, broadcast application（SF）, hole application（XF）, and furrow application（GF）. In each treatment, we measured soil nitrogen, yield, as well as water and fertilizer use efficiencies.【Result】Both nitrate and ammonium content decreased with soil depth, and they accumulated in 0~20 cm under SF and in 0~40 cm under XF and GF. Following fertilizer application, nitrate and ammonium contents peaked earlier under XF and GF than under SF. Under XF, GF and SF, soil nitrate peaked after 10 days, 10 days and 20 days of fertilization, with a peaked content of 93.85 mg/kg, 103.95 mg/kg and 78.5 mg/kg respectively; while soil ammonium peaked 5 days, 10 days and 10 days after fertilizer application, with a peaked content of 47.6 mg/kg, 48.4 mg/kg and 36.9 mg/kg respectively. Applying the fertilizer via holes or furrows considerably increased its uptake by plant and the subsequent allocation to the grains. For example, under XF, the nitrogen harvest index increased by 11.5% compared with SF, and 33.2% and 27.2% respectively compared to CK1 and CK2. 【Conclusion】XF and GF considerably increased the yield, as well as water and fertilizer use efficiency compared to other treatments, especially XF.