华北农牧交错区两种土壤类型下青饲玉米的施氮效应

Effects of Nitrogen Application on Forage Maize Planted in Two Soil Types in Agriculture-Animal Husbandry Ecotone of North China

针对华北农牧交错区饲草量少质差的现实问题,在区域草甸栗钙土和沙质栗钙土条件下,研究了氮肥不同施用量对青饲玉米产量与品质形成及肥水利用效果的影响。结果表明,草甸栗钙土田和沙质栗钙土田施氮比不施氮青饲玉米生物产量分别增加36.1%和106.0%,植株氮素含量分别提高108.0%和81.9%,且在草甸栗钙土田出现氮素的奢侈吸收现象;施氮使草甸栗钙土田玉米植株磷素含量提高10.9%,但沙质栗钙土田玉米磷素含量降低;玉米植株粗蛋白、粗脂肪的含量和产量均随施氮量增加而显著增加,草甸栗钙土田分别增产1.60倍和2.10倍,沙质栗钙土田分别增产2.74倍和1.36倍;施氮显著提高青饲玉米的水分利用效率,草甸栗钙土田增幅为27%-45%,相当于多供水82.5-135.7mm;沙质栗钙土田增幅为95%-97%,相当于多供水294.9-258.5mm。故华北农牧交错区青饲玉米施氮是快速提高饲草产量和营养品质以及高效利用肥水资源的有效技术手段,草甸栗钙土田不超过200kghm^-2、沙质栗钙土田不少于135kghm^-2,是兼顾玉米产量、品质与肥水高效利用的适宜施氮量。

To solve the actual problems of shortage and bad quality of forages in current agriculture-animal husbandry ecotone of North China, a field experiment was conducted to study the effects of nitrogen application rate on biomass yield, forage quality, fertilizer and water use efficiencies of forage maize （Zea mays L.） in meadow chestnut and sand chestnut soils. The results indicated that nitrogen application increased the forage maize biomass yield by 36.1% and 106.0% in meadow chestnut and sand meadow chestnut soils, respectively, and significantly improved nitrogen absorption in forage maize plant. The nitrogen content in plant increased by 108.0% and 81.9% compared with that without nitrogen application, and the extravagant absorption of nitrogen by plant occured in meadow chestnut soil. Nitrogen application also increased the phosphorus content in forage maize plant by 10.9% in meadow chestnut soil, but decreased in sand chestnut soil. In the two soil types, the content and yield of crude protein and crude fat of the forage maize were enhanced significantly with the increase of nitrogen application. The yields of crude protein and crude fat increased by 1.60 and 2.10 times in meadow chestnut soil, and by 2.74 and 1.36 times in sand chestnut soil, respectively. The nitrogen application increased the water use efficiency （WUE） of the forage maize by 27%-45%, equivalent to a surplus supply of 82.5-135.7 mm water in meadow chestnut soil, and by 95%-97%, equivalent to a surplus supply of 294.9-258.5 mm water in sand chestnut soil. Thus it concluded that nitrogen for forage maize is an effective technique to improve biomass, nutrition quality, and fertilizer and water utilization efficiencies in the area, nitrogen applications of less than 200 kg ha^-1 in meadow chestnut soil and more than 135 kg ha^-1 in sand chestnut soil were appropriate to ensure high yield and good quality as well as high nitrogen fertilizer and water use efficiencies of forage maize.