Soil Water Conservation Effect, Yield Increament Of Maize In Diffrerent Tillage And Fertilization Patterns On Weibei Highland

Located in the central part of Shaanxi Province, Weibei Highland belongs to a typical rain-fed agricultural region, it’s an important grain food and fruit production center with abundant land and light-temperature resources, but it’s water resource is relative scarce, natural rainfall occupies an dominant part in the process of agricultural production, while its distribution is extremely uneven in terms of time and location and its utilization efficiency is very low, which often results to the unstable and low productivity of local agriculture and the stagnation of farmer’s income. In recent years, the number of livestock decreased annually, which led to the deduction of farmyard manure, besides, the over-applying of chemical fertilizers have caused serious ecological problems as well as extra economical burden for local agricultural production, this was another bottleneck hindering the highly efficient development of local agricultural. It has long been a focus for researchers in the field of arid area agriculture to find the right way of conserving rainfall and enhancing rainfall utilization efficiency, the unreasonable utilization, over-using as well as the unreasonable proportion of fertilizers were also the problems to be solved. Through the combination of fertilization and tillage practices, water utilization efficiency could be enhanced by the reduced evaporation and increased water conservation under the condition of straw mulching, while fertilizer utilization efficiency could be enhanced when fertilizers were reasonably proportioned, the objectives of regulating water through fertilizer and yield enhancing were reached through the coupling effects of water and fertilizer. In this study, 3 different tillage practices combined with fertilization regimes were set, namely, conventional farmer pattern(deep plough plus low fertilization level), existent highly efficient pattern(no-tillage plus high fertilization level) and innovative highly efficient pattern(sub-soiling plus moderate fertilization level), the effects of water conserving, water utilization efficiency and fertilizer utilization efficiency were respectively studied. Besides, a control treatment without fertilizer applied was set in each plot to investigate the effect of fertilization, the utilization efficiency of nitrogen and phosphorus, thus finding the appropriate conservative tillage practices and fertilization patterns and providing technical supports for the corn yield enhancing of Weibei Highland.(1)Effects of different conservative tillage practices and fertilization patterns on soil physical properties and soil water dynamicsAll the 3 conservative tillage practices could improve soil bulk density and porosity, innovative highly efficient pattern(sub-soiling plus moderate fertilization level) performed the best, whose 0~60cm soil bulk density reduced 5.3%, soil porosity increased 5.5% while 0~200cm soil water capacity increased 23.3mm than that of conventional farmer pattern(deep plough plus low fertilization level); Compared to conventional farmer pattern(deep plough plus low fertilization level), existent highly efficient pattern(no-tillage plus high fertilization level) decreased 0~60cm soil bulk density by 2.2%, while soil porosity and soil water capacity respectively increased 2.3% and 18.1mm.(2) Effects of different conservative tillage practices and fertilization patterns on soil fertilityThe results manifested that, compared to conventional farmer pattern, innovative highly efficient pattern and existent highly efficient pattern showed higher contents of soil organic matter, available nitrogen, available phosphorus and available potassium from 0~60cm layers underground, and it was much more obvious in the top 0~20cm layer. A larger amplitude increment of soil nutrients was respectively observed under existent highly efficient pattern and innovative highly efficient pattern in 2013 and 2014. Compared to conventional farmer pattern(deep plough plus low fertilization level), nitrogen utilization efficiency was enhanced under innovative highly efficient pattern(sub-soiling plus moderate fertilization level) in both years.(3) Effects of different conservative tillage practices and fertilization patterns on spring corn yield, WUE and net income of farmersAs precipitation was greatly differed in 2013 and 2014, a significant difference of corn grain yield was observed in 2 years. The innovative highly efficient pattern showed the best average yield performance, followed by the existent highly efficient pattern and the conventional farmer pattern showed the worst average yield performance; A similar trend was observed when no fertilizers were applied. Average grain yield and WUE of innovative highly efficient pattern respectively increased 10.1% and 11% compared to conventional farmer pattern, while existent highly efficient pattern respectively increased 7.5% and 8.3% compared to conventional farmer pattern. Existent highly efficient pattern reduced the utilization of machines, increased corn yield and performed best in terms of net income, followed by innovative highly efficient pattern, and conventional farmer pattern showed the lowest net income.All in all, innovative highly efficient pattern(sub-soiling plus moderate fertilization level) could efficiently break soil structures of plough layer, improve soil physical properties, enhance water conservation during winter fallow, soil moisture, soil fertility, corn grain yield, net income, WUE and fertilizer utilization efficiency, its a proper production pattern for spring corn of Weibei Highland.