Effects Of Water And Fertilizer Coupling On Yield And Quality Of Greenhouse Potatoes In Yan’an Region

In order to find out the optimal irrigation flow,water quantity and reasonable fertilizer dosage in the potato production system in Yan’an area.In this paper,the“Netherlands No.15”virus-free seed potato planted in large area in northern Shaanxi was used as the material.The experiment was completely randomized to fully water（100%ET₀）and local recommended fertilization amount(F:N-P₂O₅-K₂O was240-120-300 kg·hm^-2),3 irrigation volumes（W1:100%ET₀;W2:80%ET₀;W3:60%ET₀）and 3 fertilization levels(F1:240-120-300 kg·hm^-2;F2:180-90-225 kg·hm^-2;F3:120-60-150 kg·hm^-2),consisting of 9 treatments(T1,100,240-120-300 kg·hm^-2;T2,80%ET₀,180-90-225 kg·hm^-2;T3,60%ET₀,120-60-150 kg·hm^-2;T4,100%ET₀,180-90-225 kg·hm^-2;T5,80%ET₀,120-60-150 kg·hm^-2;T6,60%ET₀,240-120-300kg·hm^-2;T7,100%ET₀,120-60-150 kg·hm^-2;T8,80%ET₀,240-120-300 kg·hm^-2;T9,60%ET₀,180-90-225 kg·hm^-2),set 60%ET₀ irrigation,no fertilization and no The mulching treatment was used as the control group（CK）for a total of 10 treatments.The experimental data were collected to study the regulation of water and fertilizer coupling on potato growth,yield and quality,and to systematically explore the effects of drip fertigation on soil physical and chemical properties and soil moisture.ring.The test achieved the following main results:（1）The interaction of water and fertilizer had important effects on plant height,stem diameter,leaf area,of potato.Fertilization is beneficial to the growth of potato plant height,stem diameter and leaf area.During the whole growth period,the plant height,stem diameter and leaf area of the potato were showed continue to increase.Excessive fertilization inhibited the plant height 7-21 days after emergence.After emergence,the growth rate of potato plant height increased by continuous fertilizer application.The trend of increasing first and then decreasing.In addition,the results also showed that the irrigation had no significant effect on plant height and stem diameter.Reasonable irrigation and fertilization could increase the chlorophyll content of leaves.The chlorophyll content of T1 treatment was the highest,and followed by T9 treatment.The reasonable supply of water and fertilizer could increase the chlorophyll of leaves,and enhances enzyme activity to promote photosynthesis and increase crop yield.（2）Different fertilzation and irrigation had significant effects on soil moisture content and distribution under potato roots.The difference in irrigation water amount leads to the change of water accumulation soil layer.The larger the irrigation amount,the water accumulation layer will migrate downwards.When the irrigation amount is exactly equal to the water demand of the potato,the soil moisture accumulation layer is located in the upper layer of soil（0-30cm）.Different irrigation fertilization had significant effects on water consumption of potato growth stages（p<0.05）.There were positive relationship between potato water consumption and irrigation amount,and positive correlated with fertilization amount,and negatively correlated with seedling stage and starch accumulation period.The increase of irrigation is conducive to the increase of potato yield and quality.Different fertilization has significant effects on potato water use efficiency（p<0.05）.Appropriate irrigation and fertilization is beneficial to the absorption and utilization of potato root water..The highest yield,in treatment of T9,indicating that T9 treatment is most suitable for the water demand supply of potato.The ratio of water to fertilizer is most suitable for the growth of potato.（3）Fertilizer application has a significant effect on yield increase.Drip fertilization significantly affects the physical and chemical properties of soil,including soil pH,conductivity,nitrate nitrogen,alkali nitrogen,available phosphorus and available potassium content and distribution.Under the same fertilization amount,the pH value and available potassium content will decrease increase by water application rate.The conductivity value,nitrate nitrogen content,alkali nitrogen content and organic matter content will show with the decrease.The pH value showed the trend of decreased at first and then increased with the increase of fertilizer application rate;the conductivity value,nitrate nitrogen content,alkali nitrogen content,available phosphorus content and the amount of fertilization increased.The content of organic matter showed an trend of irregular increasing.With the increase of fertilizer application,the available potassium showed an trend of decreasing.The soil of T9 treatment has the higher nutrient content,and the accumulation layer is located in the upper layer of soil（0-30cm）,and conducive to the absorption and utilization of potatoes.（4）This study found that the irrigation and fertilization,as well as water and fertilizer interactions significantly affected potato starch content,reducing sugar content and soluble sugar.In medium fertilizer treatment,the yield showed the trend of increasing at first and then decreasing with the increasing of irrigation water.Under high fertilizer treatment,the yield increased by the increasing of irrigation water.There were obvious growth advantage and small coefficient of variation in T9treatment.The content of potato starch increased at first and then decreased with the increase of fertilizer application.The starch content of T9 treatment was the highest under the condition of water and fertilizer supply,and the effect of water and fertilizer interaction on the starch content of potato tuber was very significant.The nitrogen fertilizer could make the stem dry matter.The accumulation amount is significantly improved,and the content of tuber reducing sugar and total sugar can also be increased.It indicated that proper amount of water and fertilization could significantly increase the content of reducing sugar and soluble sugar in potato.Reasonable fertilization significantly increased potato starch content and reducing sugar content.In this study,T9 treatment had higher quality,less variation coefficient and more stable.