Effects Of Water And Fertilizer Management On Potato Yield And Quality

In order to explore to obtain high-yield and high-quality potatoes in Yan’an area,two trials were conducted in March-July and August-December 2019.The virus-free potato"Holland No.15"is used as the test material.Based on the full irrigation W1（100%ET0）and the recommended fertilizer rate F1(N-P2O5-K2O:240-120-300 kg·hm^-2)in the area,three irrigation levels W1,W2（80%ET0）and W3（60%ET0）,three fertilization levels F1,F2（75%F1）and F3（50%F1）two factor three level test.(W3F1:60%ET0,N-P2O5-K2O:240-120-300 kg·hm^-2;W2F3:80%ET0,50%F1;W1F2:100%ET0,75%F1;W3F3:60%ET0,50%F1;W2F2:80%ET0,75%F1;W1F1:100%ET0,N-P2O5-K2O:240-120-300 kg·hm^-2;W3F2:60%ET0,75%F1;W2F1:80%ET0,N-P2O5-K2O:240-120-300 kg·hm^-2;W1F3:100%ET0,50%F1),CK is 60%ET0 irrigation,no fertilization and film mulching,a total of 10 treatments.To study the regulating relationship between water and fertilizer management on the growth status,tuber quality,yield and soil nutrients and moisture of potato root zone.The results of this study are as follows:（1）Throughout the growth period,different water and fertilizer management could promote the growth of potato shoots.20 days after emergence,increased application of fertilizers will inhibit plant height growth.Plant height increased first and then decreased with the increase in irrigation;30-40 days after emergence,the stem thickness gradually slowed down.With the increase of irrigation amount and fertilization amount,the stem diameter increased first and then decreased;the overall leaf area showed a slow growth trend.At the same level,as the amount of fertilization and irrigation increased,the leaf area first increased,then decreased,and then increased slowly.The W3F1 treatment had the highest chlorophyll;the average values of plant height,stem thickness and leaf area of W2F2 treatment were relatively highest.（2）The nutrient content of the 0-40 cm soil layer in the potato root zone was higher than 50-60 cm.At the same fertilization level,nitrate nitrogen,organic matter,available nitrogen,available phosphorus,electrical conductivity and ammonium nitrogen increased first and then decreased with the increase of irrigation water.Available potassium and pH first decreased and then increased with the increase of irrigation water.At the same irrigation level,nitrate Nitrogen,available potassium,available phosphorus,pH,organic matter,and alkali-hydrolyzable nitrogen increased first and then decreased with the amount of fertilizer.The soil nutrient content of W1F3treatment was relatively high,and the nutrients were mainly distributed in the 0-40 cm soil layer,while the underground part of the potato grew in the soil layer 0-30 cm,which was suitable for the growth of potato tubers.（3）During the whole growth period,the water consumption in the seedling stage was the highest,and the water consumption in the W1F3 treatment was the highest.For the same irrigation level,the water consumption first increased and then decreased with the increase of the fertilization amount.The same fertilization level,the water consumption increased with the increase of the irrigation amount.The water in the potato root zone was mainly distributed in the 0-30 cm soil layer.With the increase of irrigation water,nutrients were leached and migrated to the deep soil layer along with the water.Under repeated experiments,the highest water use efficiency of W1F1treatment was 113.06 kg·hm^-2·mm^-1,and the highest yield increase rate of W2F2treatment was 133.48%.（4）The single yield of W1F1 treatment was as high as 35,979 kg·hm^-2,and the average yield was the highest for W1F1 treatment:26,164 kg·hm^-2,and the yield of W1F3 treatment was 22,837 kg·hm^-2.Under high fertilizer（F1）and low fertilizer（F3）,the yield increased with the increase in irrigation volume,under medium fertilizer（F2）,the yield first increased and then decreased with the increase in irrigation volume;under medium water（W2）and low water（W3）,Yield increased first and then decreased with the increase of fertilizer application.Under high water（W1）,the output first decreased and then increased with the increase of fertilizer application.The highest starch and total soluble sugar content were W3F2 treatment,the highest crude protein content was W2F1 treatment,the highest reducing sugar content was W3F1 treatment,the browning intensity was the lowest,W3F2 treatment,the highest total potassium content was W3F3 treatment,and the highest total phosphorus content was W1F1 treatment,W3F2processing was in second place.At the same irrigation level,starch and total phosphorus first decreased and then increased with the increase in fertilization,and crude protein and total potassium first increased and then decreased;at the same fertilization level,starch,total potassium,and crude protein increased first and then decreased with the increase in irrigation,and total phosphorus followed the increase in irrigation volume first decreased and then increased.The entropy weight method was used to comprehensively analyze potato yield,quality and root zone nutrient moisture.The W1F3 treatment scored the highest,and the W3F3 treatment ranked second,but there was no difference between the two groups.Comprehensive analysis of potato growth indicators,tuber yield and quality,and soil nutrients and moisture,while taking into account factors such as water and fertilizer saving,it is recommended that W3F3(60%ET0,120-60-150 kg·hm^-2)is the local recommended fertilization quantity and irrigation volume.