不同青贮玉米品种与紫花苜蓿的间作效应

Intercropping of Different Silage Maize Cultivars and Alfalfa

不同青贮玉米品种与紫花苜蓿的间作表明，间作青贮玉米边际效应显著，并因品种和生育时期的不同而异。大喇叭口期，间作青贮玉米光照强度和透光率比单作的提高，在基部为15．3％～88．1％和15．1％～89．0％，在中部为52．1％～74．1％和51．2％～73．0％。全生育期内，间作青贮玉米平均透光率比单作的提高，在基部为49．5％～62．1％，中部为40．7％～56．6％。5～30cm土层地温从上到下呈递减趋势，同一土层温度均为间作高于单作；5cm土层生育期内的平均地温间作比单作提高了1．0％～1．8％。收获期，间作青贮玉米株高、茎粗和叶面积指数比相同种植面积的单作玉米分别提高了2．3％～20．9％、0．4％～7．6％和2．2％～19．6％。间作复合群体的粗脂肪和粗蛋白含量比单作玉米分别提高了30．8％～59．1％和99．4％～137．5％，而鲜草和干草产量比单作玉米分别降低了22．7％～32．3％和17．6％～28．2％，比单作紫花苜蓿分别提高了156．7％～202．4％和176．5％～197．5％。间作紫花苜蓿初花期鲜草和干草产量及粗脂肪和粗蛋白含量表现出边行劣势，但差异不显著。综合分析表明，间作复合群体可充分利用田问光照和地温条件，并且紫花苜蓿是多年生豆科牧草，具有覆盖地面、防风固沙、培肥地力的作用，第2年5～6月份即可收获第一茬，不仅可以解决内蒙古因缺草而影响养殖业发展的问题，而且为间作青贮玉米提供了较大的生长空间。

Intercropping has been studied and practiced widely for crop production, but it has seldom studied in the forage production. In this paper, intercropping system of different silage maize cuhivars and alfalfa was studied in regard to physiological ecology of the system, yield and quality of products. Results showed that marginal effect of silage maize was remarkable, and it changed with silage maize cultivars and growth stage. As compared with monocropping of silage maize, at male tatrad, light intensity and light transmission of intercropping silage maize was increased by 15.3%-88.1% and 15.1%-89.0% respectively at bottom of plants population, and 52.1%-74.1% and 51.2%-73.0% at middle layer of plant population; average light transmission for whole growth stage was increased by 49.5%-62.1% at bottom, and 40.7%-56.6% for middle part; average temperature of five centimeters soil layer at whole growth stage increased by 1.0 %-1.8 %. At the harvest period, plant height, stalk thickness and green leaf area of cuhivars Keduo 4, Keduo 8, Keqing 1 in intercropping system were 2.3%-20.9% ,0.4%-7.6% and 2.2%-19.6% greater than those for monocropping. Crude protein and crude fat contents in plant intercropping system were increased by 30.8 %-59.1% and 99.4 %-137.5 % respectively compared with those for monocropping maize. The yields of green forage and hey for intercropping system were decreased by 22.7%-32.3% and 17.6%-28.2% as compared with monocropping maize, and increased by 156.7 %-202.4% and 176.5 %-197.5 % as compared with monocropping alfalfa. Crude protein and crude fat contents, green forage and hey yields of alfalfa in intercropping system were slightly decreased at early flowering stage, but there were not significant difference between two cropping systems. Integrated analysis indicates that intercropping system can take advantage of light, temperature resources of local fields sufficiently. In addition, alfalfa is perennial legume, which can cover the fields, fix and fertilize soil, therefore protect soil from wind erosion. The harvest of alfalfa from May to June next year not only solves the problem of forage shortage for livestock husbandry in Inner Mongolia but also provide bigger space for the growth of intercropping silage maize.