Effect Of Soil Surface Mulching On Water And Fertilizer Utilization And Grain Yield Of Winter Wheat In Weibei Dry Highland

Drought and water shortage has become a key factors which restriction increase China's grain output. In the Weibei rainfed agricultural areas of the Loess Plateau, water shortages and low soil fertility has limited the development of local agricultural production seriously. Therefore, how to find effective measures to improve limited precipitation resource use efficiency of crop, and to improvement of soil fertility, which is becoming the key of local agricultural production. Above these problems, we design the different treatments in our experiment. The experiment main purpose to maximize the gathering of natural precipitation, decline the soil water evaporation and increase water use efficiency of crop; moreover raise soil fertility, improving soil structure to increase soil water storage capacity, making the crop seeding more vigorously, and creating a better growth environment for crops. The field experiment was conducted from September 2007 to June 2009 in the Wang Donggou of Changwu Ecological Experimental Station of Chinese Academy Weibei Dry Highland of the Loess Plateau. The main objective of this research was to investigate the effects of different cultivation modes on the soil water from 0 to 200 cm depth of soil layer, plough soil temperature at 10 cm depth of soil layer, the yield and water use efficiency of winter wheat and soil nutrients. The experiment consisted of 7 treatments, namely, no fertilization (CK), conventional fertilization (N1P1), recommended fertilization (NP), recommended fertilization + manure (NPM), recommended fertilization + plastic mulch on soil ridges (NP+PF), recommended fertilization + plastic mulch on soil ridges and straw mulch in furrows (NP+PF+S) and recommended fertilization + straw mulch on entire plot (NP+S). The results showed:(1) Mulching the soil surface improved the soil water storage during the dry season (spring). During the spring of 2009 (dry season), the NP+PF and NP+PF+S treatments improved the soil water storage within the depth of 2 m soil layer. The average soil water storage of Yuan surface and Terrace in these treatments was more 24.8 mm and 21.6 mm in comparison with the CK treatment.(2) The mulching modes also increased the soil temperature during the over-winter stage (Dec. 2008 to early Feb. 2009). In comparison with the CK treatment, NP+S, NP+PF+S+F and NP+PF+F treatments increased the average soil temperature by 0.26℃, 0.26℃and 0.33℃, respectively. But after the returning green stage, the NP+S, NP+PF+S and NP+PF+F treatments decreased the soil temperature, and the total accumulated temperature decreased by 150℃, 44.5℃and 35.3℃in comparison with the CK treatment.(3) The data also showed that the NP+PF+S and NP+PF treatments significantly increased the yield and water use efficiency of winter wheat. Meanwhile, the NP+S treatment had a little effect on the yield and water use efficiency.(4) The data of two years showed that, wherever the Yuan surface or the terrace, the grain of winter wheat could absorb more N, P and K under NP+PF+S and NP+PF treatments. In the first quarter winter wheat, the average N, P, K of Yuan surface and Terrace in NP+PF+S and NP+PF treatments was more 48.0%,53.6%,53.2% and 44.0%,39.6%,46.3% in compared with CK treatment; In the second quarter of winter wheat, the NP+PF+S and NP+PF treatments had much higher N, P, K uptake than CK treatment too.(5) The data of two years also showed that the N1P1 treatment had significant NO3-1-N accumulation in the deeper soil layer during 0 to 2 meter soil layer, in compared with other treatments. However, the NP+PF+S and NP+PF treatments had not significant NO3-1-N accumulation, if had a little NO3-1-N accumulation, it was focused on above 100 cm soil layer. We came conclusion that excess fertilization result the crops absorbing incompletely and nutrient wasted, and the more soil water can promote the crops absorption nutrient in the surface soil layer.(6) Although soil organic matter had an increasing trend in some treatments, such as NP+PF+S and NP+M treatments, was not significant each other. Therefore, we should as an deeper research from improving soil fertilizer.(7) Although the spikier numbers of NP+PF+S and NP+PF treatments were significantly lower than other treatments, the other yield components, 1000-grain weight particularly, were significantly higher than other treatments. In conclusion, though the cultivation mode of ridge and furrow declined the spike number, the yield increased was uninfluenced.(8) In the second quarter, the crude protein content of NP+PF+S and NP+PF treatments higher than other treatments. However, the crude protein content of NP+S treatment the lowest than other treatments. We came to the conclusion that the better soil water and temperature was beneficial to improve the quality of winter wheat grain.