Effects Of Straw Mulching And Nitrogen Application On Soil Moisture- Thermal And Summer Maize Growth Under Drip Irrigation

Straw mulching is an important conservation tillage measures has been widely popularized in the world, many scholars think straw mulching can store water and retain soil moisture, regulating temperature, increasing the fertilizer, improving the soil and production. Drip irrigation is a widely accepted technique for high efficiency in fertilization and irrigation. Drip fertilization can reduce loss of nutrients, groundwater pollution and soil salinization etc. In this study, drip irrigation fertilization and straw mulching were combined. The effects of straw mulching and nitrogen application on soil water and heat change and crop growth in summer maize field were analyzed under the condition of drip irrigation. This paper reveals the effect of straw mulching on the yield increasing of drip irrigation and fertilizer application. This research can further improve the coverage measures and provide a scientific basis for the management of water and Fertilizer on dry land.A two-year field experiment was conducted at Daxing. Summer maize was selected as the research object. This paper sets the two kinds of covers processing (not covered, covered 5500 kg/hm2) and three types of fertilizer treatments (low fertilization 0, middle fertilization 200 kg/hm2, high fertilization 400 kg/hm2). In this paper, the index of soil water and heat condition, the physiological and ecological index and yield of summer maize were observed periodically. The main conclusions are as follows.(1) Under the condition of drip irrigation, there was a significant difference between the evaporation of soil in the wet and dry area on both sides of the drip irrigation zone. Straw mulching could significantly reduce the evaporation. Whole growth period can reduce evaporation 20%～30% while the effect of nitrogen fertilization on evaporation was not obvious. Straw mulching can effectively regulate the distribution of water in different depth of soil layers. Surface soil moisture can be intercepted. The average soil water content of each treatment during the whole growing period was 20-40>40-60>0-20cm.(2) Straw mulching has a regulatory effect on the surface soil temperature. The diurnal variation of soil temperature becomes smaller. The lowest temperature increase, the most high temperature reduction.(3) Under the condition of drip irrigation, straw mulching and nitrogen fertilizer could promote the plant height, leaf area and dry matter accumulation of summer maize. Straw mulching increased the average plant height 10.31%～27.72%, increased the leaf area index 15.77～40.26%, and increased the dry matter accumulation 6.63%～13.75%. Fertilization could increase dry matter accumulation 5.32%～9.23%.(4) Under the condition of drip irrigation, straw mulching promoted the increase of yield. During the two-year trial, the yield increased by an average of 7.17%～12.45%. Straw mulching has a positive effect on increasing WUE, and the average increase of 5.13%～10.58% in the two years. Each treatment LAI and E/ET showed a good exponential correlation.