The Effect Of Water And Fertilizer Coupling On Potato's Yield And Fertilizer Using Efficiency Dripping Irrigation Under Mulch In Ningxia Drought Region

The experiment was carried out with uniform design to research the effect of water and fertilizer coupling on potato's yield and fertilizer using efficiency dripping irrigation under mulch in Ningxia drought region,The regression models were established by stepwise regression to conduct analysis.The results showed:(1)The percentage of irrigation amount at seeding period,budding stage and initial boom stage to the whole irrigation quota was 25%,25%,50%,respectively.(2)the experimental factors followed by the importance which had affected on potato yield ranged as follows:irrigation norm,nitrogen fertilizer and potash fertilizer,and the effect of phosphate fertilizer application on potato yield and the soil phosphorus content had a direct relationship.(3)The irrigation norm and the nitrogen fertilizer had synergistic effect,and the nitrogen fertilizer and the potash fertilizer had antagonistic effect.The interaction of phosphate fertilizer and potash fertilizer on potato yield had the greatest impact.Applicating nitrogen when filling water helps to increase production,nitrogen and potash fertilizer should applicate in different time.(4)Increasing irrigation norm was conducive to improve the using efficiency of P,K fertilizer,and increasing nitrogen and phosphate fertilizer was conducive to improve the using efficiency of K fertilizer.Increasing fertilizer would cause a decline in corresponding fertilizer using efficiency,the using efficiency of N fertilizer was higher,when irrigation norm was between 60 to 85 m3/667m2.(5)The effect of each experimental factor in the order the using efficiency of P,Nfertilizer were associated with the soil background values.the experimental factors followed by the importance which had affected on the using efficiency of K fertilizer ranged as follows:potash fertilizer phosphate fertilizer nitrogen fertilizer and irrigation norm.(6)Fertilizer using efficiency would achieve the optimal,while the irrigation norm,nitrogenous fertilizer,phosphate fertilizer,and potash fertilizer were 76.8m3/667m2,2.0kg/667m2,3.4kg/667m2 and2.3kg/667m2,respectively.The fertilizer using efficiency and the yield had a contradiction,to meet the requirements of yield must use low fertilizer using efficiency,and the fertilizer waste is inevitable.(7)The water and fertilizer scheme was associated with the soil background values,According to the yield model and fertilizer using efficiency analysis,The water and fertilizer scheme recommend as:irrigation norm was 55-70m3/667m2,nitrogenous fertilizer was 5.5-10.5kg/667m2,phosphate fertilizer was 7.0-18.0kg/667m2,and potash fertilizer was 5.0-6.0kg/667m2.The specific water and fertilizer amount should determine by the soil background values.