Effects Of Different Irrigation Amount And Nitrogenous Fertilizer Base Ratio On Potato Growth And Soil Enzyme Activity

In view of the shortage of water resources,low water and fertilizer utilization efficiency and low soil ecological environment quality in the arid area of central Ningxia this experiment adopted a completely randomized design with 2 factors and 3 levels to study the effects of different irrigation amounts and nitrogen fertilizer base and topdressing ratios on potato soil invertase and alkalinity.The influence of phosphatase activity,growth index,yield,quality and distribution of soil water and nitrogen,as well as the correlation analysis between each index and soil enzyme activity,recommends a water and nitrogen management mode for planting potatoes and improving potato soil fertility in the arid areas of central Ningxia.The main conclusions are as follows:(1)Potato soil invertase and alkaline phosphatase activities both increased first and then decreased with the progress of the potato growth period,and both reached the maximum during the tuber growth period.In the vertical direction,the activities of potato soil invertase and alkaline phosphatase also decreased with the increase of soil depth.Comprehensive analysis W3N2:1 treatment is beneficial to increase soil invertase activity and alkaline phosphatase activity,W1N2:1 treatment is not conducive to the improvement of 0～40cm soil invertase activity,and W2N2:1 treatment is not conducive to 0～20cm soil.The increase of invertase activity,W1N2:1 treatment is not conducive to the increase of soil alkaline phosphatase activity of 20-40cm soil layer,and W3Ni:i treatment is not conducive to the increase of invertase activity and alkaline phosphatase activity of 40～60cm soil layer.(2)W3N2:1 treatment is beneficial to increase potato plant height and stem thickness growth,while W1N1:1 treatment is not conducive to potato plant height and stem thickness.Rough growth.The relative content of potato chlorophyll showed a downward trend during the growth period.W3N2:1 treatment was beneficial to increase the relative content of potato chlorophyll,while W3N1:2 treatment was not conducive to increase the relative content of chlorophyll.Potato stem thickness was significantly positively correlated with soil invertase activity in the 40～60 cm soil layer.(3)Irrigation and top-dressing nitrogen fertilizer are beneficial to the increase of potato yield,large and medium potato yield and the rate of commercial potato.W3N2:1 treatment is beneficial to increase potato yield.Both potato yield and big potato yield are significantly positively correlated with 0～20cm soil invertase activity,extremely significantly positively correlated with 20～40cm soil invertase activity,and 20～40cm soil alkaline phosphatase The activity showed a very significant positive correlation;the yield of potato medium was significantly positively correlated with the invertase activity of the 20～40cm soil layer and the soil alkaline phosphatase activity of the 20～40cm soil layer.W3N2:1 treatment is beneficial to improve the quality of potatoes,while W1N2:1,W1N1:2 and W1N1:1 treatments are not conducive to the improvement of potato quality.The reducing sugar content of tubers was significantly negatively correlated with the invertase activity of the 20～40cm soil layer and the soil alkaline phosphatase activity of the 20～40cm soil layer.The total potato yield was extremely negatively correlated with the reducing sugar content,the large potato yield was extremely negatively correlated with the reducing sugar content,and the vitamin C content was significantly positively correlated,the medium potato yield was extremely significantly positively correlated with the starch content,and the medium potato yield was extremely significantly correlated with the starch content.There is a significant positive correlation with the content of vitamin C.Principal component analysis method was used for comprehensive evaluation of potato yield,quality and soil enzyme activity.W3N2:1 treatment had the highest comprehensive score,and CK treatment had the lowest comprehensive score.(4)In the vertical direction,the soil moisture content and soil nitrate nitrogen content of each treatment decreased as the soil depth deepened.W1N1:1 treatment has the highest irrigation water use efficiency and water use efficiency;W3N1:1 treatment has the lowest irrigation water use efficiency and water use efficiency.W3N2:1 treatment has the highest nitrogen fertilizer agronomic efficiency and nitrogen partial productivity;W1N2:1 treatment has the lowest nitrogen fertilizer agronomic efficiency and nitrogen partial productivity.The soil moisture content of the 0～20cm soil layer is significantly positively correlated with the soil invertase activity of the 20～40cm soil layer,and the soil moisture content of the 40～60cm soil layer has a very significant positive correlation with the soil alkaline phosphatase activity of the 0～20cm soil layer;The soil moisture content of the 60～80cm soil layer is significantly positively correlated with the 0～40cm soil layer invertase activity,and the 0～20cm soil layer has a very significant positive correlation with the soil alkaline phosphatase activity.The 80～100cm soil layer has a significant positive correlation with the soil moisture content of 0～40cm soil layer.The activity of soil invertase in the 0～40cm soil layer was significantly positively correlated with that of the soil alkaline phosphatase activity of the 0～40cm soil layer,and that of the soil alkaline phosphatase activity of the 40～60cm soil layer was significantly positively correlated.Under comprehensive consideration of the experimental conditions,W3N2:1 treatment is recommended(irrigation quota W3:1800m3/hm~2,nitrogen fertilizer base to dressing ratio:2:1,nitrogen application rate:187.5kg/hm~2,phosphorus application rate:82.5kg/hm~2,potassium application Quantity:150kg/hm~2)As a water and nitrogen management mode for planting potatoes and improving potato soil fertility in the arid regions of central Ningxia..