关键词: 青饲玉米, 施氮, 产量, 营养品质, 氮、磷利用, 水分利用

Abstract: 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.

Key words: Forage maize (Zea mays L.), Nitrogen application, Biomass, Nutrition quality, Nitrogen and phosphorus utilization, water utilization