Effects Of Different Water And Fertilizer Measures On Water And Fertilizer Use Efficiency And Crop Yield In Irrigation Area Of Yellow River Diversion

Recently,with the rapid development of social productive forces and economics,agriculture in China has improved in some degree.However,the water-fertilizer use efficiency is still fairly low,waste of water and agricultural pollution become more and more serious.In order to ensure crop yields,choosing reasonable water fertilizer treamenr measure is an important method to increase the water-fertilizer use efficiency and descrease the waste of water-fertilizer.The paper regards winter wheat as study object,the pilot zone is in Weishan Irrigation District,Liaocheng City,Shandong Province.The characteristics of soil water content change and distribution of nitrogen in soil profile were analyzed by setting up various fertilization irrigation schemes.The effects of different water-fertilizer treatment measures on growth and yield of winter wheat,crop water and nitrogen use efficiency were analyzed as well.According to pit test and simulation results of DSSAT-CERES-Wheat model,the best water and fertilizer treatment measures were selected.The main conclusions of this paper were shown as following:(1)Through the study of the change law of soil moisture content,it shows that the effect of different fertilization irrigation schemes on soil moisture content was not significant.After winter wheat harvest,the average soil moisture content was 25%~31%.In the same amount of fertilizer,the soil moisture content increased with the increase of irrigation.The results show that crop water use efficiency of No.3 pit was the highest,and irrigation water use efficiency of No.6 pit was the highest.In order to ensure the yield and improve the use efficiency of water,the irrigation quota was 675 kg/hm~2 and the nitrogen application rate was 198 kg/hm~2should be chosen in practical production.(2)Based on the analysis of the distribution characteristics of nitrogen concentration in soil profile,it shows that during the growth period of winter wheat,nitrate nitrogen mainly distributed in 40-120 cm,and irrigation amount was the main factor affecting the distribution of nitrate nitrogen.Ammonium nitrogen mainly concentrated in more than 80 cm,and fertilization amount was the main factor affecting the distribution of ammonium nitrogen.Total nitrogen mainly distributed in 40-160 cm,compared with fertilization amount,irrigation amount was the dominant factor in the vertical distribution of total nitrogen.(3)According to the analysis of nitrogen fertilizer utilization rate calculation,shows that the effective utilization rate of nitrogen in No.3 pit was the highest,reaching 39.5%.When the amount of fertilizer was insufficient,the partial productivity of nitrogen fertilizer decreased with the increase of irrigation.(4)The plant height and leaf area of winter wheat were more significantly affected by irrigation,while the accumulation of dry matter was mainly affected by fertilization.According to the study on growth index and water and nitrogen use efficiency of winter wheat,it thows that irrigation had more significant effect on winter wheat yield than fertilizer application.Water was the main factor causing the fluctuation of winter wheat yield under certain conditions.(5)Combined with pit test and DSSAT-CERES-Wheat model simulation results,the optimal water and nitrogen management scheme of Winter Wheat in this area was selected irrigation quota of 700 m~3/hm~2,three times of irrigation,and applied nitrogen amount of180-200 kg/hm~2,of which 50%was used for bottom application and 50%was used for topdressing at jointing stage.