| In this study,the resources distribution,grain yield,and resource use efficiency of different cropping systems were analyzed,and the quantitative evaluation index such as resource distribution rate and ratio between seasons were set up.As a result,the advantage of winter wheat-summer maize in grain yield,resource us efficiency,and benit was clarified.Then the resource distribution between two seasons was optimized by changing sowing date of wheat and harvest date of maize,and the effect of different resource distribution method on crop growth and yield formation of wheat-maize was clarified.Finally,the water saving and high yield cropping system for wheat-maize was established by integration of key cultivation techniques.(1)The resources distribution,grain yield,and resource use efficiency of different cropping systems in huang-huai-hai area were clarified,and the quantitative evaluation index such as resource distribution rate and ratio between seasons were set up.The cropping systems which including C4 crop,especially for double C4 cropping has a higher yield potential and efficiency of resource utilization.It indicates that highlights the advantage of high photosynthesis and high water use efficiency is the key way to increase grain yield and resource use efficiency of crop in huang-huai-hai area.However,considering the importance of winter wheat as rations and adjustment for maize planting structure in China,the double maize cropping system can be used as a useful supplement in this area,but can’t take place of winter wheat and summer cropping system.(2)Compared with traditional sowing/harvest date for.wheat-maize(I),the sowing date delayed until early December in the treatment V,in which wheat can not emergence before the winter,then the waste of resources in winter have been reduced(539.4 ℃ accumulated temperature,318.8 MJ m-2 radiation,150 mm irrigation water),and avoid the affect by drought and cold.However,the grain yield of wheat has not reduced,and the radition,temperature,and water resources use efficiency improved significantly.On the other hand,the harvest date of maize delayed to mid November,the amount of resources for maize increased significantly(675.4 ℃ accumulated temperature,465.5 MJ m-2 radiation,62.0 mm precipitation),which promoted dry matter accumulation and transportation at late growth stage of maize.As a result,the grain yield of maize increased significantly,and the water content of grain decreased significantly.Therefore,compared with traditional sowing/harvest date for wheat-maize(I),the annual grain yield and water use efficiency of treatment V increased by 8.4%and 52.2%,respectively,and the water consumption reduced by 38.3%.(3)Compared with traditional sowing/harvest date for wheat-maize(I),the grain yield of two wheat varieties(ZM66 and BN418)of the treatment V has not reduced,and maize yield increased significantly,so the annual yield increased significantly.Due to the significant reduction in the amount of accumulated temperature for each stage of wheat in the treatment V,the leaf area index and dry matter accumulation for each stage decreased significantly(except flowering to mature),but the grain number and harvest index increased significantly.As a result,the grain yield of ZM66 and BN418 has not significantly reduced.However,with the delay of the harvest,dry matter accumulation,kernel weight,and grain yield of maize increased significantly,and DH605 and XY335 have the highest yield.At the same time,the grain water content decreased significantly,and it is below 20%at the fourth harvest.(4)Compared with local traditional sowing/harvest date of winter wheat-summer maize,the annual grain yield increased by 14.4%,economic benefit increased by 5900 yuan hm-2. |
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