Study On Regulating Rainwater Of Different Stages In Dryland Of Western Liaoning

The primary problem in western Liaoning is that there has no synchronization between the temporal and spatial distribution and crop production. Drought is one of the major natural disasters of agricultural in this area. Therefore, storing and scientific using rainwater has become an important part in western Liaoning. The key to develop dryland agriculture depends on resisting the drought in spring in this region. And how to improve the inception of the rainfall, to heighten the capability of the soil acceptance and to lower the evaporation of the soil surface are all important. The purpose of this experimentation is analyzing the effects of plastic film-mulching in autumn and plastic film-mulching in early spring on soil field environment and the growth of maize in western Liaoning. The main results are as follows:The average soil temperature and soil water are significantly improved by the treatments of plastic film-mulching in autumn and plastic film-mulching in early spring. The soil water content by plastic film-mulching in autumn is higher than plastic film-mulching in early spring and CK in 0～40cm layer. It is significant in 0～10cm layer. Close to the soil surface, the effects on soil temperature are very obvious. The results show that plastic film-mulching in different periods could create favorable conditions for the growth of maize.In 0～40cm layer, either before sowing in the spring or after harvesting, the treatments of plastic film-mulching in autumn and plastic film-mulching in early spring reduce the soil pH; as soil temperature and soil water are significantly improved, microbial activity is increased, accelerating the mineralization of the soil organic matter, and resulting in substantial decomposition of phosphorus. The soil temperature rising and soil water content increasing promote the effective of soil nitrogen. Some of the clay mineral lattices are destructed, A number of soil fixed K are released. At the same time, some of the acid promotes the decomposition of potassium minerals.Yield of maize of plastic film-mulching in autumn is 5741.98 kg/hm2 compare to 5228.56 kg/hm2 of plastic film-mulching in early spring and 3909.28 kg/hm2 of CK. Yield of maize of plastic film-mulching in autumn increases by 46.88% and 9.82% compared with plastic film-mulching in early spring and CK. Yield composition factors(spike,kernels per spike and 100grain weight),the height and stem diameter of maize of plastic film-mulching in autumn are all larger than plastic film-mulching in early spring and CK. The results show that plastic film-mulching in autumn could significantly increased maize yield.Water use efficiency is increased by the treatments of plastic film-mulching in autumn and plastic film-mulching in early spring. The Water use efficiency of plastic film-mulching in autumn is 21.47kg/mm-hm2 compare to 19.22kg/mm-hm2 of plastic film-mulching in early spring and 14.86 kg/mm-hm2 of CK. Water use efficiency of plastic film-mulching in autumn and film-mulching in early spring increases by 44.52% and 29.35% compared with CK. Thus, the treatment of plastic film-mulching in autumn could improve water use efficiency obviously and this treatment is a efficiency measure for western Liaoning which average annual rainfall is 350-500mm.In this paper, field plot experiment is done to study the effects of saving water and increasing maize yield by the treatments of film-mulching in autumn and film-mulching in early spring. The results show that the effects of increasing soil water content and soil temperature by film-mulching in autumn are better than film-mulching in early spring. Therefore, the results could provide the theoretical basis and technical supports for western Liaoning.