Study On Planting Arrangement Of Double-Cropping System For Wheat And Summer-Corn And Its Techno-Economic Effectiveness

Henan province is located in the middle-lower Yellow River valley in the north of China. It has a continental climate of the North Temperate Zone, with contrast different seasons of hot, rainy summer, dry, inclement winter and windy spring. It has a mean annual temperature of 15.5℃-9.5℃increasing from south to north, a mean annual precipitation of 526.0-1380.6 mm, an annual sunshine hour of 1740-2310 h, and an annual frost-free period of 265-332 days. The climate is suitable for the growth of wheat and corn because its plenty precipitation in the summer season. In order to coordinate the growth of wheat-corn and fully utilize the resources of sunshine and field productivity to increase the crop yield and farmer benefits, we analyzed the planting arrangement of wheat-corn, yield potentials, the meteorological factor and the key stages. We also evaluate the techno-economic effectiveness of this planting model. The main results were as following:1. Twenty-six counties or cities were clustered by group-average method using seven principal components which extracted from 46 indexes including the climate and soil fertility data and average yield of wheat and corn in the past years. Six planting regions were divided based on the 26 representative counties or cities. RegionⅠ, including 12 representative counties or cities, which covered most area of north, east and partially middle Henan province, can be divided into 4 subregions. RegionⅡ, including 9 representative counties or cities, covered south and middle areas of Henan province. RegionⅢincludes Yanshi city and Jiyuan city. SubregionsⅠ-1,Ⅰ-2,Ⅰ-3 and regionsⅡ,Ⅲwere favorite regions for planting wheat and corn in Henan province. SubregionⅠ-4 was the second favorite regions for planting wheat and corn in Henan province. RegionⅣincluded only Wenxian county, was most apt for planting wheat and corn in Henan province because of plentiful heat resource, fertile soil and high quality irrigation conditions. Region V, only Lushi county, was suitable for planting wheat and millet (sweet potato). Region VI, only Xinyang county, was a double maturation cropping region on wheat and rice.2. The photosynthesis productivities were estimated based on total radiation of wheat and summer corn seasoning. The photosynthesis productivities of wheat were 6598.5-7531.5 kg/hm2 with the average of 7110.15 kg/hm2 and variant coefficients was 3.8% on the 2% of the whole utility rate of luminous energy condition. The mean wheat yield in Henan province in 2008 was 5798.48 kg/hm2 and the utility rate of luminous energy was 1.63%. If the utility rate of luminous energy can reach 3%, the wheat photosynthesis productivities can reach 6223.5-8100.0 kg/hm2 with the average of 7220.3 kg/hm2. Equally with the wheat, corn has the similar tendency. The photosynthesis productivities of corn were 6223.5-8100.0 kg/hm2 with the average of 7220.3 kg/hm2 and variant coefficients was 7.46% under 2% of the whole utility rate of luminous energy condition. The mean corn yield in Henan province in 2007 was 5715.0 kg/hm2 and the utility rate of luminous energy was 1.58%. If the utility rate of luminous energy can reach 3%, the corn photosynthesis productivities can reach 9336.0-12150.0 kg/hm2 with the average of 10830.6 kg/hm2.3. The optimum regression equation was built based on organic contents and basement yield using soil fertilities components in wheat-corn seasoning. The relationship of basement yield and organic contents was curvilinear regression of second degree. The highest basement yield of wheat was 2889kg/hm2 when the organic contents reached 1.39%, while the yield of summer corn was 16433kg/hm2 when the organic contents reached 5.51%. It can be concluded that the basement yield of summer corn increased with the organic contents. The optimum yield of wheat was decreased when the basement yield increased and the basement yield of different soil type was as following: yellow cinnamon soil>cinnamon soil>moisture soil>red clay>sajiang black soil> paddy soil. The optimum yield was the different tendency, paddy soil>sajiang black soil >red clay>moisture soil>cinnamon soil>yellow cinnamon soil. The basement yield has the different level with different region of Henan province, southern west of Henan> northern Henan>southern Henan>western Henan>eastern Henan, while the optimum yield was the different tendency, eastern Henan>western Henan>southern Henan> northern Henan> southern west of Henan. On the contrary, the corn optimum yield was increased when the basement increased, the basement yield and optimum yield had the same tendency of different soil type, paddy soil>sajiang black soil>cinnamon soil> yellow cinnamon soil> moisture soil> red clay. The optimum yield and basement yield of summer corn in different region of Henan province had the tendency of southern Henan> southern west of Henan> western Henan> northern Henan> eastern Henan.4. The climate yield model was built based on the main climate affections and key stages in wheat and corn growing periods by taking climate of counties or cities as dependent variable and taking temperature,precipitation and sunshine hours as independent variables. The equations of partial regression, coefficients between climate yield and mean temperature, or precipitation or sunshine hours were all significant with the correlation coefficients were above 0.9631. The main affection factor to yield of wheat and summer corn was temperature and the key stage was changed with the different regions.5. The techno-economic affections were evaluated using the data of high-yield cultivation and super-high-yield cultivation in Xun county institute academy in 2005 and the input and output data of high-yield cultivation in Xiping county. The mean input value of wheat high-yield cultivation was 71-1115.60 Yuan/666.7m2 and the benefit was 46.18-518.24 Yuan/666.7m, they were negative significant the correlation coefficients was-0.936 and the benefit ratio was 0.04-0.74 Yuan/Yuan. The marginal benefit of fertilizer was 0.58-1.66 Yuan/666.7m2 with the average of 1.25 Yuan/666.7m2. The marginal benefit of watering was 3.70-15.62 Yuan/666.7m2 with the average of 8.55 Yuan/666.7m2. The marginal benefit of pesticides was 7.35-15.24 Yuan/666.7m2 with the average of 9.15 Yuan/666.7m2. We can concluded that the pesticides can got the best benefits and the watering is the second. The mean yield in high-yield cultivation was 490.9kg/666.7m2 with the average output value of 834.53 Yuan/666.7m2. Comparing with super-high-yield cultivation, the input values were different in high-yield cultivation and the variant coefficients was 11.06%-66.56%. The input value of fertilizer was different and the variant coefficient was 40.97%.6. The mean yield of summer corn on super-high-yield cultivation was 916.32kg/666.7m2 with the mean output value of 1282.87 Yuan/666.7m2, input value of 866.50-1221.50 Yuan/666.7m2, benefits of 103.50-454.20 Yuan/666.7m2. the correlation coefficients was-0.640 and the benefit ratio was 0.12-0.44 Yuan/Yuan with the average of 0.25 Yuan/Yuan. The highest marginal benefits were watering which was 5.20-27.32 Yuan/666.7m2 and the average was 17.43 Yuan/666.7m2. The second was pesticide which was 7.17-12.78 Yuan/666.7m2 with the average of 10.55 Yuan/666.7m2. The marginal rate substitution was 1.65. Comparing with super-high-yield cultivation, the input value were decreased sharply in high-yield cultivation, and the befits were decreased also.7. The mean output value was 2427.27kg/666.7m2 on wheat and corn integration planting. The most expensive input was the labor power with the mean of 850.67 Yuan/666.7m2 and the second was the fertilizer with the average of 649.22 Yuan/666.7m2. the widest variant coefficients in the total input between different regions was 69.78%, while other input was changed 9.55%-19.51%. The cost was 1585.45-1969.50/666.7m2 with the average of 1753.96 Yuan/666.7m2 and the benefits of 501.00-843.15 Yuan/666.7m2. There were negative correlations between input and benefits and the correlation coefficient was-0.725. Watering and fertilizer were the similar marginal effect and had the marginal rate substitution of 7.50 and 7.58, respectively.