Effects Of Different Plastic-film Mulching And Fertilization On Production Of Spring Maize On Dryland

Drought and poor soil is the main limiting factor of spring maize production in Northwest China. According to the two factors, the double ridges and furrows Mulched with plastic film and furrow planting and the optimized fertilization technique in a large area of dryland spring maize production, significant benefit has been achieved in the spring maize yield. The long-term mulching planting and fertilization will have a certain impact on soil moisture and soil fertility. Clearing the dynamic changes of soil moisture, different ways of planting and fertilization on dryland spring maize nutrient uptake and yield stability of soil nutrients, the law, to improve the spring maize on dryland cultivation and fertilization level, implementation spring maize in this area has important significance of high yield, high quality, and sustainable production. Based on the spring maize as the test material,field experiment was conducted in Dingxi city of Gansu Province during 2012~2014, where locates at semi arid area of northwest of China. Three different planting involved in the field experiment, 1) double ridges and furrows mulched with plastic film and furrow planting(F), 2) half covered and flat planting(H), and 3) open and flat planting(O). Three fertilizations involved in also, 1) optimized fertilization(OPT), 2) farmer conventional fertilization(FP), and 3) no fertilization(CK). The growth period of maize, water content of soil nitrate nitrogen residue, dry matter accumulation, nutrient absorption amount after harvest, the soil nutrient content and yield and yield components were measured. The soil water consumption, water storage, the vertical variation of water content and water use efficiency; yield and harvest index during the whole growth period of spring maize nutrient uptake; soil nutrient variation of interannual and residual nitrate nitrogen. The main results are as follows:1. F and OPT was the optimal coupling,which yield, water use efficiency and water consumption were 12900 kg·hm-2, 27.9 kg·hm-2·mm-1 and 246.2mm respectively, also was the highest in all treatment. Compared with O-CK, the yield and water use efficiency increased by 168.7% and 106.2% respectively. The OPT fertilization in H and O planting ways did not improve the yield and water use efficiency(compared with FP). The maximum water consumption is during the filling period. After harvest, F-OPT soil moisture deficit compared before sowing, while other treatments were compensated, which soil soil water near 140 cm layer was less than 10%. Therefore, F-OPT can significantly increase the yield and water use efficiency of spring maize, but the long-term planting was not conducive to the sustainable production of spring maize in semiarid region.2. Plastic film-mulching and fertilization can significantly promote the the accumulation of dry matter and NPK nutrient absorption at growth period of spring maize on dryland. The F and OPT was the best match. The amount of nutrient absorption of spring maize in the order: N>K>P. The average grain harvest index in F treatment was 55%, but the effects of fertilization on grain harvest index was not significant. The nutrient harvest index and agronomy efficiency of fertilizer in F-OPT treatment was the highest, and its nutrient harvest index of N, P, and K were 78.3%, 88.9% and 28%, respectively, also the agronomic efficiency were 31.4 kg·kg-1, 1.5 kg·kg-1and 2.4 kg·kg-1, respectively. Besides, the agronomy fertilizer efficiency of P and K was less than the national average, while the agronomy fertilizer efficiency of N was far far above the national average level. The F-OPT could maintain N balance basically, but a large number of surplus in P and greatly deficient in K.3. From the changes of soil nutrients between 2 years, under different planting patterns of fertilization is 0~20cm after the unification, the content of available phosphorus increased, fertilization had no significant effect on the content of soil organic matter, nutrient content in different planting methods were different. Among them, the whole film double furrow sowing and fertilization membrane for two kinds of no increase in other nutrient content, soil cultivation, two kinds of fertilization fertilization significantly increased 0~60 cm soil total nitrogen content, the optimum fertilization also increased the content of available potassium in soil. The whole film double furrow sowing time planting promote soil fertility decreased rapidly, the planting mode of optimized fertilization did not significantly improve the soil nutrient content.4. For 3 years fertilization, the amount of soil residual nitrate in 0~200 cm layer up to 428.3 kg·ha-1. The amount of residual nitrate is proportional to the nitrogen application. And OPT is the highest in the 3 fertilizations of the average nitrate nitrogen residue. The residual nitrate nitrogen mainly distributed in 60~140 cm layer and near 100 cm was the highest, but not move away from maize root zone. Comparing with the flat planting(O), plastic film mulching(F and H) can reduce the residue of nitrate nitrogen caused by fertilizer, the double ridges and furrows mulched with plastic film and furrow planting(F) is particularly evident.