A Systematic Study On Adaptability Of Maize-maize Double Cropping In The Hebei Plain

In order to develop a new cropping system that suitable for the Hebei Plain tosupplement to the existing cropping systems, ecological adaptability and economicviability of spring maize-summer maize double cropping were studied via a fieldexperiment. The experiment was conducted on the Experimental Station of ChinaAgricultural University in Quzhou county, in2012and2013. Experiment set twocropping systems: spring maize-summer maize covered ridge planting and winterwheat-summer maize flat planting. A pilot experiment on summer maize after springmaize with the cultivar Zhengdan958was conducted in2012. In2013, the experimentwas carried out with spring maize-summer maize in2013set three cultivar combination,Demeiya1(early mature type)-Zhengdan958(one of the most popular cultivars),Chengdan22(early mature type)-Xianyu335(one of the most popular cultivars) andXianyu335-Chengdan22. Winter wheat-summer maize was compared as the control.Winter wheat cultivar use in the experiment was Liangxing99, one of the most popularones in the area and the maize cultivar used in the wheat-maize system was Zhengdan958. The main results were summarized as follows:（1）Compared with the winter wheat-summer maize system, annual growth periodof spring maize-summer maize system decreased by139days. There was no significantdifference in annual yield between early mature-medium mature type of springmaize-summer maize system and the winter wheat-summer maize system., while that ofthe medium matureeearly maturecultivar combination of spring maize-summer maizesystem was lower than the winter wheat-summer maize system. Compared to the winterwheat-summer maize system, spring maize-summer maize system obtained53.7%~76.6%higher water use efficiency,9.7%~29.0%higher energy productivity, and12.7%~29.0%higher solar radiation use. Temperature productivity of the earlymature-meduim mature cultivar combination maize-maize system was6.9%~8.2%higher than the wheat-maize systems, while that of the medium mature-early maturecultivar combination maize-maize system was7.6%lower. No significant difference ofannual energy productivity was found between the maize-maize and the wheat-maizesysems. The two early mature-medium mature cultivar combinations of maize-maize system were higher than the wheat-maize system in net economical return, but themedium mature-early mature combination was26.1%lower than the wheat-maizesystems.(2) There were differences between different cultivar combinations in maize-maizesystem. Compared to the medium mature-early mature combination, the earlymature-medium mature combination was16.1%~17.4%higher in yield,14.9%higher inwater use efficiency,14.7%~17.6%higher in energy efficiency,15.7%~17.0%higher intemperature production efficiency, and32.9%~34.6%higher in net economical returen,than medium mature-early mature.(3) There are adequate thermo degree days to fit the cultivar combinations of earlymature-early mature, early mature-medium mature and medium mature-early mature inBeijing where there were4418.2degree days above, the early mature-early maturecombination requiring4200~4800degree days above10℃can be adapted. It isrecommended that areas to the south of Xingtai (with4783.1thermo degree days above10℃) to use early mature-medium mature cultivar combination (which requires4600~5100thermo degree days above10℃), and to the north of Xingtai to use earlymature-early mature cultivar combinaiton.Spring maize-summer maize double cropping adapts well in the Hebei Plain givenproper cultivar combination. It can be used as a supplement cropping system to the winterwheat-summer maize system in the area, or be used as a remedy after winter kill ofwinter wheat.