Effects Of Irrigation At Different Growth Stages And Nitrogen Nutrition On Growth And Water-Nitrogen Utilization Of Spring Wheat In Hexi Area

To study the spring wheat at different growth stages of irrigation and nitrogen fertilization under physiological adaptive mechanisms, and in the stress conditions of nutrient transport mechanisms.Agricultural and ecological saving-water experiment station in China Agricultural University of Shiyang river basin. The spring wheat Yongliang 4 was selected as test materials in Wuwei Region of Gansu, The field experiment treatment consists of two factors: at different growth stages of irrigation and nitrogen levels of spring wheat,different growth stages of irrigation: no irrigation located seedlings, no irrigation at jointing stage, with no irrigation at heading stage, filling with no irrigation and the seedling stage and filling stage with no irrigation 5 treatments were also set up a growth period of Irrigation as a control; set four levels of nitrogen were 0kgN/hm2 (N0), 60kgN/hm2 (N1), 120kgN/hm2 (N2) and 180kgN/hm2 (N3). Determination of each growth period of spring wheat plant height, leaf area index, chlorophyll, biomass accumulation, yield and yield components of spring wheat, biomass accumulation, nutrient distribution, roots zone soil nitrate content analysis to explore the different growth stages irrigation on spring wheat growth and nutrient transport. The main results as follows:(1). There had significantly effect on plant height, leaf area index, canopy fresh weight and canopy dry weight of spring wheat no irrigation treatments at the seedling stage, jointing stage, heading stage, seedling stages + filling stage compared with the treatment of irrigation at whole growth stages,while the treatments of no irrigation at the seedling stage and seedling stages + filling stage had significant impact on root fresh weight and root dry weight. The treatments of no irrigation at heading and filling stage had no significantly effect on plant height of spring wheat. At different growth stages irrigation treatment of spring wheat N had a certain promotion on plant height, leaf area index, aboveground and root fresh weight, aboveground and root dry weight.(2). There had significantly effect on chlorophyll of spring wheat no irrigation treatments at the seedling stage, jointing stage, heading stage , filling stage compared with the treatment of irrigation at whole growth stages, and seedling stages no irrigation treatment had more influence on chlorophyll of spring wheat, nitrogen application increased chlorophyll content, and positively correlated with nitrogen.(3). There had significantly effect on yield of spring wheat no irrigation treatments at the seedling stage, jointing stage, heading stage, seedling stages + filling stage compared with the treatment of irrigation at whole growth stages,while at different growth stages irrigation treatment had significantly effect on 1000-grain weight of spring wheat, Under irrigation at different growth stages of spring wheat grains per spike, effective small ears per square meter, yield increased with nitrogen into the rise.(4). Different growth stages of irrigation and nitrogen fertilizer on nitrogen uptake of spring wheat have some effect. There had significantly effect on steam and leaf nitrogen accumulation of spring wheat no irrigation treatments at the seedling stage, jointing stage, heading stage, seedling stages + filling stage compared with the treatment of irrigation at whole growth stages, while the treatments of no irrigation at the seedling stage and seedling stages + filling stage had significant impact on root nitrogen accumulation. No irrigation treatment at different growth stages to root nitrate content in soil increased seedling N content in soil with no irrigation larger, with no irrigation at jointing stage, heading stage with no irrigation, no irrigation of nitrate filling gradually migration to deeper soil layers; N contents in different soil depth and a positive correlation between nitrogen.