Experimental Study On The Effects Of Nitrogen Distribution Ratio On Growth And Nutrient Uptake Of Potato Under The Condition Of Water And Fertilizer Integration

Aiming at the low utilization rate of nitrogen fertilizer in potato in the arid region of central Ningxia,using "Qingshu 9" as the experimental material,the randomized block experimental design was used to study the changes of growth and physiological indexes and nitrogen uptake of potato under different nitrogen application ratios.Regularity;explore the effects of nitrogen application rate allocation on potato water consumption,yield,yield composition,quality,dry matter and fresh weight of tuber;study the changes of soil nitrogen and potato root zone water content.The test results are as follows:(1)The plant height,stem diameter and leaf area of the potato in the whole growth period increased first and then tended to be gentle.The growth rate of the tuber formation period was faster,and the growth rate was slower after the tuber formation period The three indicators of photosynthesis of potato plants were A double-peak curve is first imcrease4 then decreased,and then increased The morning peak is greater than the afternoon peak.(2)From the nitrogen content of potato organs,the nitrogen content of leaves was the highest,the tuber was the second,the nitrogen eontent of roots and stems was not significantly different,and the content was smaller than that of leaves and tubers.The nitrogen uptake of potato tubers was the largest,followed by leaves and stems,and the nitrogen uptake was the smallest From the nitrogen absorption rate of different growth stages,the nitrogen uptake intensity of potato during the whole growth period showed a first increase.The trend of further reduction reached the maximum during the tuber growth period;the nitrate nitrogen was mainly distributed in the 40-60 cm soil layer at the maturity stage,while the ammonium nitrogen was irregularly distributed;the higher the nitrogen application rate in the later stage,the lower the soil nitrogen.The apparent loss of the pigment maintains the fertility of the soil,but it also causes the waste of nitrogen fertilizer.(3)The difference of nitrogen application rate at each growth stage had sigxuficant effect on the water content of potato root zone.When the soil moisture content of potato root zone was 15.78%to 19.50%,potato had the lowest water consumption and the highest yield,reaching 67.47t/hm2.In the arid zone of central Ningxia,no nitrogen fertilizer at the seedling stage significantly reduced the water use efficiency of the potato.(4)The dry matter variation curve of potato plants treated with nitrogen in central Ningxia accorded with the Peel growth curve,and the growth curve function was y=220.60/1+673.640e-0.087x-.(5)A reasonable fertilization system can promote the growth of potatoes,increase the photosynthetic rate of leaves,increase the accumulation of dry matter of plants,increase yield,improve quality,and improve water use efficiency and nitrogen.use efficiency of potatoes.The proportion of nitrogen fertilizer in seedling stage,tuber formation stage,tuber growth stage and starch accumulation stage was 10%,30%,40%and 20%,and the water supplementation period was set at seedling stage,tuber formation stage and tuber growth stage,respectively.When the irrigation quota is 25%,25%and 50%,the growth and physiological indexes are the best,the yield is the highest,the quality is the best,the water use efficiency and nitrogen use efficiency are the highest,and the dry matter and tuber fresh fruit weight are accumulated reasonably in each growth period.