减氮配施氮肥增效剂对土壤速效氮和玉米产量的影响

过量施氮一直是玉米生产中存在的主要问题,而配施氮肥增效剂可作为减氮条件下玉米实现高产和稳产的一种重要技术措施。2016—2017年在四川省德阳市中江县合兴乡新建村设置田间试验,研究不同施氮量与氮肥增效剂配施对土壤速效氮含量和玉米干物质积累及产量的影响,为玉米减氮增产栽培技术提供科学依据。结果表明:减氮配施增效剂能够增强土壤速效氮供应能力,促进玉米干物质积累,改善产量构成,提高玉米产量,实现玉米减氮不减产。常规氮和减氮20%配施增效剂增产幅度分别为5.53%～13.97%和10.24%～17.05%,减氮配施增效剂的增产效果更好。减氮20%条件下A_2B_4脲酶活性和土壤硝态氮含量较A_2B_2、A_2B_32年平均分别降低了19.00%,15.65%和-2.97%,57.24%,土壤铵态氮含量和产量2年平均提高11.48%,248.50%和3.71%,6.18%。综上,减氮20%条件下硝化抑制剂(DCD)和脲酶抑制剂(HQ)复配土壤速效氮的供应能力最强,可实现玉米减氮不减产。

Effects of Nitrogen Reduction Combined with Nitrogen Fertilizer Synergist on Soil Available Nitrogen and Corn Yield

Excessive nitrogen application has been a major problem in corn production, and combined application of nitrogen fertilizer synergist can be used as an important technical measure to achieve high and stable corn yield under the condition of nitrogen reduction. In 2016 and 2017, field experiments were set up in Xinjian Village, Hexing Township, Zhongjiang County, Deyang City, Sichuan Province, to study the effects of different nitrogen application rates and nitrogen fertilizer synergists on soil available nitrogen content and dry matter accumulation and yield of corn, so as to provide scientific basis for reducing nitrogen and increasing yield cultivation techniques of corn. The results showed that the nitrogen reduction combined with synergist could enhance the supply capacity of available nitrogen in soil, promote the accumulation dry matter of corn, improve the yield composition, increase corn yield, and achieve nitrogen reduction without yield reduction. The yield increase ranges of the conventional nitrogen treatment and 20% nitrogen reduction combined with synergist treatment were 5.53%~13.97% and 10.24%~17.05%, respectively. The yield increasing effect of nitrogen reduction combined with synergist was better. Under the condition of reducing nitrogen by 20%, compared with A₂B₂ treatment and A₂B₃ treatment, urease activity and soil nitrate nitrogen content of the A₂B₄ treatment decreased by 19.00%, 15.65% and -2.97%, 57.24%, respectively, and the soil ammonium nitrogen content and yield increased by 11.48%, 248.50% and 3.71%, 6.18% on average in the two years. In summary, under the condition of reducing nitrogen by 20%, the combination of nitrification inhibitor (DCD) and urease inhibitor (HQ) had the strongest supply capacity of soil available nitrogen, which could reduce nitrogen application without reducing corn yield.