【作者】 叶优良；

【导师】 张福锁；

【作者基本信息】 中国农业大学 ， 植物营养学， 2003， 博士

【摘要】 间作由于具有充分利用资源和增加作物产量的特点，在我国西北地区广泛应用。近年来，生产中氮肥用量不断增加，灌水用量也相对较高，但是关于间作对氮素和水分利用效率的研究较少。本文通过田间试验，对小麦／玉米、蚕豆／玉米、大豆／玉米和豌豆／玉米间作种植下作物对氮素和水分利用的影响进行了系统比较，获得的主要结果如下： （1）蚕豆／玉米间作的土地当量比（LER）都大于1；豌豆／玉米间作以籽粒产量为基础的LER无论施氮还是不施氮都大于1，而以生物学产量为基础的LER只有施用氮肥时才大于1；大豆／玉米间作无论施氮还是不施氮LER均小于1。小麦／玉米间作，施用氮肥时的LER均大于1，而不施氮时，不同小麦品种和试验条件下表现不一样。 （2）蚕豆／玉米和豌豆／玉米间作时作物的吸氮量均高于单作，小麦／玉米间作时小麦吸氮量高于单作，玉米吸氮量低于或接近单作；而大豆／玉米间作时间作大豆吸氮量低于单作，间作玉米吸氮量高于单作。蚕豆、豌豆和大豆、小麦间作的氮素利用效率均高于单作，而玉米间作则低于单作。 （3）蚕豆、豌豆、大豆和小麦间作氮素盈余和损失都低于单作，氮肥当季利用率和生产率都高于单作。 （4）随氮肥用量增加，土壤硝态氮含量和累积量亦增加。蚕豆和豌豆间作土壤硝态氮累积量都高于单作，而大豆、小麦和玉米间作在不同时间和不同氮水平下表现不一样。 （5）在蚕豆收获后测定时，蚕豆、豌豆、大豆和小麦间作土壤含水量都高于单作，玉米间作则低于单作；而在玉米收获后测定，间作玉米土壤含水量都高于单作。蚕豆／玉米间作相对于单作水分利用率（WUE）增加，豌豆／玉米和小麦／玉米间作在施用氮肥后增加，而大豆／玉米间作无论施氮还是不施氮都降低。 （6）不同灌水用量对小麦／玉米间作产量影响不大，施用氮肥后作物产量增加，但225与450kg·hm^-2施氮量之间产量无明显差别。随氮肥用量增加，玉米带土壤硝态氮含量和累积量明显增加，且随灌水量增加，硝态氮向140cm以下土层累积。氮肥当季利用率利氮肥生产率都是以225kg·hm^-2氮水平最高。WUE随灌水用量减少或氮肥用量增加而增加，但225kg·hm^-2与450kg·hm^-2施氮量之间差别较小。更多还原

【Abstract】 Intercropping, due to the more effective use of resources and high productivity, is practiced widely in northwestern China.In recent years, nitrogen application rate is increasing continually, and irrigated water input is also relatively great. However, the research on nitrogen and water use efficiency are very few. Our work reported here are aiming at improving nitrogen and water use efficiency in wheat/maize, faba bean/maize, pea/maize and soybean/maize intercropping through field experiment.The main results obtained were as the following:(1) Land equivalent ratio (LER) was greater than 1.0 for faba bean (Viciafaba L.)/maize (Zea mays L.) intercropping regardless of nitrogen fertilizer application or not. Based on grain yields production, LER of pea (Pisum sativum L.)/maize intercropping was over 1.0 in spite of nitrogen fertilizer application, while LER was higher than 1.0 only when nitrogen fertilizer was applied based on biomass production. However, LER in soybean (Glycine max L.)/maize intercropping was smaller than 1.0 both nitrogen applicationa and no nitrogen application. In wheat (Triticum aestivum L.)/maize intercropping, LER was greater than 1.0 when nitrogen fertilizer was applied, and LER was varied with wheat varieties and experiment conditions without nitrogen fertilizer application.(2) Nitrogen uptake by intercropped faba bean and maize was greater than those in sole cropping, semilar trends were observed in pea/maize intercropping.Nitrogen uptake of intercropped wheat was higher in wheat/maize intercropping than that in sole cropped wheat, and nitrogen uptake of intercropped maize was lower or close to that in sole cropped one. In contrast, intercroped soybean was less than that by sole soybean,whereas nitrogen uptake by intercropprd maize was greater that that by sole maize in soybean/maize intercroping. Nitrogen utilization efficiency in intercropped faba bean, pea, soybean and wheat was greater than that in corresponding sole cropps, however, intercropped maize was lower than that in sole cropped maize.(3) Nitrogen surplus and nitrogen loss were less, and apparent nitrogen recovery by plants, nitrogen production rate were generally greater in intercropped faba bean, pea, soybean and wheat than those in sole cropped faba bean, pea, soybean and wheat respectively.(4) Soil NO3"-N concentration and accumulation were increased with increased nitrogen application. NO3"-N accumulation in soil of intercropped faba bean and pea were grater than that in sole faba bean and pea, but varied with different nitrogen application and time in intercropped soybean, wheat and maize.(5) Soil water contents in intercropped faba bean, pea, soybean and wheat were higher than those in corresponding sole crops, and the content in intercropped maize was decreased compared with sole maize when determined after faba bean harvesting. After maize harvest, soil water contents in intercropped maize were grater than that in sole cropped. Water use efficiency (WUE) of faba bean/maize intercropping relative to sole cropping was increased with or without nitrogen application, pea/maize intercropping and wheat/maize intercropping were increased after nitrogen fertilizerapplication, yet soybean/maize intercropping were reduced regardless of nitrogen fertilizer application or not.(6) Different irrigation level hardly affected yields of wheat/maize intercropping. Grain yields improved with increased nitrogen rate, however, there was little difference between application of 225 kg.hm-2 and 450 kg.hm-2 nitrogen rate. NO3--N concentration and accumulation in soil of maize strip increased obviously, and moved below 140 cm soil depth with the raise of irrigation rate. Apparent nitrogen recovery by plants and nitrogen production rate were the highest at 225 kg.hm-2 nitrogen application rate. WUE improved with the reduction of water level and the increase of nitrogen rate, however, no big difference existed between 225 kg.hm-2 and 450 kg.hm-2 nitrogen application.更多还原