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【目的】明确玉米条带不同追施氮量对间作作物产量、吸氮量和土壤硝态氮动态变化的影响,并阐明间作系统不同施氮量的后茬农学效应和环境效应。【方法】玉米和大豆播种时均施用相同的基肥(其中氮肥用量为N 45kg/hm2),根据大喇叭口期玉米条带追施氮量的不同(N0、75、180 kg/hm2)设置三个处理(N0、N75、N180),并且大豆生育期间均不追施氮肥,然后实时监测玉米和大豆各个关键生育期的生物量和土壤硝态氮动态变化,并对比分析各处理的后茬冬小麦产量和土壤硝态氮残留量。【结果】随着玉米条带追施氮量的增加,玉米条带生物量、产量和吸氮量均无显著变化,而且玉米追施氮量的多少对大豆生物量、产量和吸氮量没有明显影响。间作种植系统土壤硝态氮含量受到追施氮量的影响,氮肥追施后,0—20 cm土壤硝态氮含量显著上升,但20—40 cm土壤硝态氮含量变化不大。追施氮量越多,玉米条带和大豆条带的土壤硝态氮含量也越高,作物收获后土壤硝态氮残留量也越高,玉米条带追施N 180 kg/hm2的间作系统作物收获后土壤硝态氮含量高出其他两个处理12%25%。此外,后茬作物冬小麦产量、吸氮量并未随着前茬间作系统施氮量的增加而增加,但小麦收获后的0—100 cm土壤硝态氮残留却随着前茬间作系统施氮量的增加而增大,相对仅施用基肥而不追施氮肥的间作系统,前茬间作系统追施氮肥导致后茬小麦收获后土壤(0—100 cm)硝态氮残留量增加了22.38%70.18%。【结论】针对玉米与大豆间作种植模式,只施用玉米基肥(其中氮肥用量为N 45 kg/hm2)而不追肥,或者在施用基肥的基础上,仅在玉米条带上追施少量氮肥(N 75 kg/hm2),不会影响间作体系产量,还可降低后茬小麦0—100 cm土壤中的硝态氮残留。
【Objective】 The objective of this study was to determine the effects of different topdressing nitrogen rates on crop yield, N uptake and dynamic changes of soil nitrate nitrogen in maize straws. The agronomic and environmental effects of post-crop hybridization under different nitrogen rates were clarified. 【Method】 The same basal fertilizer (N 45kg / hm 2) was applied to both corn and soybean during planting. According to the difference of topdressing nitrogen (N0,75,180 kg / hm2) (N0, N75, N180). During the growth period of soybean, no topdressing nitrogen fertilizer was applied. Then the biomass and soil nitrate nitrogen dynamic changes in different growth stages of maize and soybean were monitored in real time. Yield and residual nitrate nitrogen in soil. 【Result】 With the increase of topdressing nitrogen, the biomass, yield and N uptake of maize bands did not change significantly, and the amount of topdressing corn did not affect the biomass, yield and N uptake of soybean Clearly affected. The nitrate content in the intercropping system was affected by topdressing amount of nitrogen. After topdressing with nitrogen fertilizer, the nitrate nitrogen content in 0-20 cm soil increased significantly, but the content of nitrate nitrogen changed little in 20-40 cm soil. The higher the amount of topdressing nitrogen, the higher the soil nitrate nitrogen content in maize and soybean strips, and the higher the residual nitrate nitrogen in the crop after harvesting. The maize strips were topdressed with N 180 kg / hm2 intercropping system Soil nitrate nitrogen content after crop harvest was 12% and 25% higher than the other two treatments. In addition, the winter wheat yield and N uptake did not increase with the increase of nitrogen application rate in the former cropping system. However, the residual nitrate nitrogen in 0-100 cm soil after wheat harvesting was not significantly different with the previous cropping system Compared with the intercropping system only applying basal fertilizer without topdressing nitrogen fertilizer, the residual nitrate nitrogen in soil (0-100 cm) increased by 22.38% 70.18 %. 【Conclusion】 In the intercropping of maize and soybean, only corn basal fertilizer (N 45 kg / hm2) was applied without top dressing, or only a small amount of nitrogen fertilizer (N 75 kg / hm2), which will not affect the yield of intercropping system, but also reduce the residual nitrate nitrogen in 0-100 cm soil of following crop.