Study On Annual Rational Utilization Of Light And Heat Resources Of Winter Wheat-summer Maize In The South Of The Hennan Province

In the Huang-huai-hai Plain,the light and heat resources of winter wheat-summer maize cropping pattern has been unreasonable by a significant warming climate and it is not absolute maturity when maize harvested.It has been restricted to the potential of lasted varieties of maize and go against mechanization of grain.Accumulative temperature of winter wheat is too high before winter because of the sowing date advancing,leading to freeze injuring in large area.It is not benefit for the increasing of grain yield and resources efficiency under this pattern.In this study,based on the analysis of large database from the resources of light and heat in Anyang,Zhengzhou and Zhumadian from 1980 to2015,combining the experiment of winter wheat-summer maize in 2014-2015,studied on the annual utilization of light and heat resources of winter wheat-summer maize in the three ecological zones and put forward the collocations of sowing date and variety to adapt for climate changing and in favor of harvesting mechanization of maize.Main results are as follows:1.From 1980 to 2015,the light resources reduced in Anyang,Zhengzhou and Zhumadian,while temperature rose significantly in February and March of wheat season in Zhengzhou and Zhumadian,particularly.When sowing date of wheat from September 21th delaying at October 20 th in Anyang,can provide more than 400℃ when it is over 16℃ and the efficiency of increasing accumulative temperature is surpass 70%.When sowing date of wheat from September 21th delaying at October 20th in Zhengzhou and Zhumadian,can provide more than 500 ℃ when it is over 16 ℃ and the efficiency of increasing accumulative temperature is over 70%.2.With sowing date delaying,yield of maize decreased.There is a trend that in early sowing with low density and high density with late sowing in Zhengzhou and Zhumadian both performed the yield increasing.It showed high yield of high-density whatever in variety and sowing date in Anyang.When the sowing date advancing,it can in favor of the SPAD of leaf and improve rate of filling,result in the yield increasing.When the sowing date was October 10 th,the yield of wheat were both less than October 20th and October 30th in Zhengzhou and zhumadian,but in Anyang,the yield of wheat at October 10th of sowing date was more than October 20 th and October 30th.3.It showed that it was advantageous to increase annual yield when maize planted in early June,harvested in early October and wheat planted in mid-October in Anyang.In this pattern,it should be chosen the varieties of maize which the accumulative temperature was about 2600 ℃and the feeble spring wheat.In Zhengzhou,it could plant maize in early June,harvested in mid-October and wheat planted in late October.And it should be chosen the varieties of maize which the accumulative temperature was about 2700 ℃ and the semi winter wheat.In Zhumadian,it could plant maize in early June,harvested in mid-October and wheat planted in late October.And it should be chosen the varieties of maize which the accumulative temperature of 2800 ℃and semi winter wheat.These patterns could make the middle or late maturing varieties achieving the potential of high yield,prevent the yield decreasing because of higher accumulative temperature before winter,and finally improve the efficiency of annual utilization of light and heat resources.