| In this experiment, the effects of different cut period of mixed cropping of alfalfa and other graminaceous grass to yield and quality were studied in 2004. And soil temperature, soil water content, dissolved nitrogen, microbe amount and intensity of illumination of alfalfa and Smooth Bromegrass mixed cropping and their effects to growth, yield, nutrient content and feeding value were studied in 2005. The main results were showed below:1. The effects of cutting in earlier blooming period and vigorous blooming period to yield and quality of alfalfa and other graminaceous mixed cropping.Dry hay yield cutting in vigorous blooming period was higher than in earlier blooming period. When cut in earlier blooming period, wet and dry hay yield of alfalfa and Smooth Bromegrass mixed cropping was the highest, and were 50.22 t/hm2 and 9.73 t/hm2 respectively; When cut in earlier blooming period, its wet and dry hay yield were 62.10t/hm2 and 12.44 t/hm2 respectively. When cut in vigorous blooming period, protein yield of alfalfa and Smooth Bromegrass mixed cropping was the highest, protein yield cut in vigorous blooming period was lower than in earlier blooming period, and were 2067.32kg/hm2 and 2064.13 kg/hm2 respectively. When cut in earlier blooming period, fat yield of alfalfa and Smooth Bromegrass mixed cropping was also the highest, the fat yield was 271.02 kg/hm2, fat yield of alfalfa and rye grass mixed cropping cut in vigorous blooming period was the highest, yield was 318.79kg/hm2; because rye grass couldn't survived in winter, we preferred the second highest group, which was alfalfa and Smooth Bromegrass mixed cropping, the fat yield was 301.64 kg/hm2.2. Soil temperature change in alfalfa and Smooth Bromegrass mixed croppingSoil temperature distinction was measured in depth of 0-30cm in a day time: intercropping and mixture cropping was higher than monoculture, Alfalfa was higher than Smooth Bromegrass in monoculture system.The soil temperature change in 15~20cm and 20~25cm in mixture cropping and in inter cropping in same row was 0.54 ℃ and 0.52 ℃, which was lower than single cropping, and alfalfa monoculture was 0.57℃, Smooth Bromegrass monoculture was 0.65℃.Soil temperature in mixture cropping system was diminished with soil layer deepened, and the extent was bigger then monoculture system. In different bearing time, the average soil temperature in 0 to 30 cm was mixture cropping higher then monoculture. From the period of seedling establishment to first florescence, the average soil temperature of intercropping was respectively 0.4 1.7, 0.6 0.7℃ higher then alfalfa monoculture, and mixture cropping was respectively-0.2 1.0 0.1 0.7℃ higher then alfalfa monoculture.Soil temperature in each patterns changed obviously before and after cutting in earlier blooming period. After cut the average soil temperature in each soil layer was higher than without cut. Theaverage soil temperature of intercropping was respectively 3°C% 3.2°C higher than without cut, and Alfafa and Smooth Bromegrass monoculture was respectively 1 °C > 1.3°C higher than without cut.3. Comparison of illumination intensity and light transmittance in mixture cropping and intercropping to monocultureIllumination in lower parts of mixture cropping was higher than monoculture. Illumination intensity in mixture cropping was higher than intercropping system. The illumination intensity in bottom part of intercropping was 45.73% and 2.02% higher than Alfalfa and Smooth Bromegrass monoculture, the illumination intensity in middle part of intercropping was 28.25% and 12.25% higher than Alfalfa and Smooth Bromegrass monoculture.4. Change on soil moisture content, alkali-hydrolyzable nitrogen content and microbe number of intercropping and mixture croppingIn each growing stage, soil moisture content of intercropping and mixture cropping in depth of 0-90cm were higher than monoculture, in monoculture, alfalfa was higher than Smooth Bromegrass. In recovery stage and branchy stage, soil moisture content of mixture cropping in depth of 0-90 cm were 13.04% and 3.89% higher than alfalfa monoculture, soil moisture content of intercropping in depth of 0-90 cm were 16.89% and 10.02 higher than alfalfa monoculture.Soil alkali-hydrolyzable nitrogen content of intercropping and mixture cropping in recovery stage in depth of 0-90cm was 35 mg/kg and 47.6 mg/kg higher than the period before winter, soil alkali-hydrolyzable nitrogen content in depth of 0-90cm was declined 67.3mg/kg in Smooth Bromegrass monoculture, and soil alkali-hydrolyzable nitrogen content before winter was only 228.1 mg/kg.In recovery stage and the period before winter, the number of sub-nitrobateria and azotobateria in intercropping and mixture cropping system were 19.81% and 26.17% more than monoculture, mixture cropping system was more then intercropping,.5. Comparison of growth, yield, nutrient content and feeding value in mixture cropping and intercropping to monocultureAlfalfa's caulis height of mixture cropping was higher than other planting patterns, the number of alfalfa's ramification in intercropping was more than other planting patterns. In three cut stage, Smooth Bromegrass's plant height, number of obvious leaves and outspread leaves in intercropping and mixture cropping system was more than those of monoculture. Smooth Bromegrass's plant height in intercropping increased 8.2% in the first cut. Number of obvious leaves and outspread leaves in intercropping was more than other planting patterns. Smooth Bromegrass's number of obvious leaves and outspread leaves in intercropping increased 12.85% and 18.6% respectively in the second cut.Yield of alfalfa and Smooth Bromegrass monoculture and in intercropping and mixture cropping were 20960.62 kg/hm2, 14343.58 kg/hm2, 22667.85 kg/hm2 and 22197.39 kg/hm2, respectively. Yield of alfalfa and Smooth Bromegrass in intercropping and mixture cropping was remarkable increased compare with monoculture, yield of alfalfa and Smooth Bromegrass in mixture croppingwas higher than intercropping.The content of crude protein in alfalfa monoculture was the highest, the next in succession was mixture cropping>intercropping> Smooth Bromegrass monoculture, the content of crude protein in alfalfa monoculture, mixture cropping, intercropping and Smooth Bromegrass monoculture were 18.46%, 15.85%, 15.69% and 10.18%, respectively. The content of crude fat in intercropping and mixture cropping was higher than monoculture. The content of crude fibre in monoculture was higher than intercropping and mixture cropping. The content of crude fiber in Smooth Bromegrass monoculture was 30.60%, which was the highest, the next in succession was alfalfa monoculture > intercropping> mixture cropping. The ash content of alfalfa monoculture was the highest, it was 9.31 %, the next in succession was intercropping> Smooth Bromegrass monoculturo mixture cropping.Total digestible nutrient, digested energy and content of metabolic energy in intercropping and mixture cropping was higher than monoculture, mixture cropping was higher than intercropping; content of total energy of mixture cropping was the highest, it was 12.36 MJ/kg, next in succession was alfalfa monoculture >intercropping > Smooth Bromegrass monoculture. Digested energy and accumulation capacity of metabolic energy of intercropping and mixture cropping were higher than monoculture, digested energy and accumulation capacity of metabolic energy of mixture cropping were 75.58% and 17100 kg/hm2. |
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