Study On Mode And Technique Of Two Harvests Silage Maize In The Temperature Limited Region Of Double Cropping System

In order to explore the new cropping system which fit to live-stock developing in farming section, the matter production, resources efficiency ,the photosynthesis performance and nutrient quality of different season, varieties .cultivation technology were studied on two-cropping silage maize system in Beijing. The results shown as follow.1.The two-cropping silage maize system with mulching film had higher 10.3% in dry matter, 12% in energy production, 12.5% in radiation light energy efficiency, 22.5% in temperature resources and 36.3% in water production efficiency than that of winter wheat-summer maize, which was traditional system. Meanwhile, it's economical benefit might arrive 10405yuan/666.7m~2, more 16.7% than that of traditional system. It means that the two-cropping silage maize system was new one with high resources efficiency and high economical benefit.2. There were two way which availability regulated resources used in two-cropping silage maize system. First one of them was enhance resources occupancy by early planting and harvesting as possible as late, which ensured more than 90% in effective accumulate temperature , 85% in nature rainfall and 70% in tall radiation of whole year. Second one was availability regulated the ratio of early spring and late summer seasons, the best ratio of early spring to late summer seasons was identified as 1.1-1.2 and 1.6 in effective accumulate temperature and tall radiation respectively by fix quantify for resources.3. The varieties could be classed into four types by different responding to environment of earlier spring and latter summer on the double-season silage maize, which were I type was the better in early spring and worse in late summer, II was better in late summer and worse in early spring, III was better both early spring and late summer and IV was worse both seasons.4. The order of matter production effect in different cultivation measurements of double cropping silage maize system was follow: the first one was mulching film effect, it made the yield to increase by 20 percentage approximately. The second one was plant density, silage maize feasible planting density was control at 111000 plants/ha. The third was seed treatment, it could enhance yield from 3% to 9%. The fourth was bunch planting, it made the yield to increase by 6 percentage .The last one was ridge culture. The technology system of double cropping silage maize was set up by different technique convention, which was mulching film, high density width-narrow row intercross of season (MHWI).5. The study on the matter accumulate and photosynthesis activity characteristic indicated as follow, (1)There was S curve which was similar as line in dry matter accumulation and had highest leaf area index (LAI) and kept stabilization, so that had high LAI duration (LAID) in double cropping silage maize system. Annual average Crop growth rate (CGR) of different cropping system was follow as, mulching film have superior over flat planting in double cropping silage maize, which more than winter wheat-summer maize system.. The CGR of different crops that summer maize was superior over earlysilage maize, higher than latter silage maize, wheat.6. The higher content organs in Acid Detergent Fiber (ADF) and NFE were leaves and stems, which were 80% of whole plant. The higher content organs in Crude Protein(CP) and Ether Extract (EE) were grains and leaves, which were more than 65% of whole plant. It has been identified that there were evidence genotype differences in those items. Synthetic analysis shown that Yi Nong 103 and Zheng Dan 958 had many advantage in nutrient quality. There were no evidence nutrient differences in mulching film plant density, bunch planting could increase CP, but the amplitude was not too much. Meanwhile, it was analyzed and proved that the total nutrient .every energy and forage value of double-silage maize had evident good benefit. The expect milk production will reached 43279kg/hm2, which was higher than the maximal value reported at present.In summary, new double cropping silage maize system, which had high matter production and high resources efficiency was set up, varieties and their cultivation was identified and the matter accumulate and activity of photosynthesis character was also studied. It provided a guideline for theory and practices which with the livestock development and adapt to planting structure regulation.