Effects Of Combination Of Chemical Fertilizer Reduction And Organic Fertilizer Increment On The Plant Growth And Soil Fertility Of Potato Production

The potato is the fourth largest food crop in China,with a large amount of chemical fertilizers and a large potential for reduction of application.The application of organic fertilizers plays an important role in promoting sustainable agricultural production.Therefore,aim to response to the national agricultural policy of"double reduction"from the"13^th Five-Year Plan",to explore the effective fertilization practices for high yield and green production in the potato system,this research selected the best fertilization proportion of organic fertilizer and chemical fertilizer,and studied the effects of combination of chemical fertilizer reduction and organic fertilizer increment on potato growth,yield and quality,nutrients uptake and utilization,photosynthetic characteristics,soil enzymes,and microbe species,and finally got the optimal combination of organic fertilizer and chemical fertilizer.Based on the intercropping of potato and corn with 2:1 rows pattern,the following experimental results were mainly obtained:1.Effects on potato field soilContents of soil available nutrients（potassium（K）,phosphorus（P）,nitrogen（N））and organic matter were increased by 6.17%,11.77%,10.11%,and 17.63%,with application of organic fertilizer.Compared with single application of chemical fertilizers,combined fertilization can provide a large amount of available nutrients for plant growth in a short time,especially in the latter growth period of potato.Additionally,the abundance of soil bacteria,fungi and actinomycetes were increased by application of organic fertilizer,and the activity of soil urease,catalase and sucrase can be improved by organic fertilizer.2.Effects on potato organ developmentCompared with single application of fertilizer,combined fertilization treatment significantly increased the LAI,the dry matter accumulation of potato roots,stems,leaves,and the configuration of potato roots such as root length,surface area,volume,number of root tips,etc.The best agronomic phenotype was observed in the treatment of combination fertilization with 80%chemical fertilizer+20%organic fertilizer.3.Effects on the photosynthetic physiology of potatoesIn the combined application treatment of chemical fertilizer and organic fertilizer,the content of photosynthetic pigment on potato leaves can be stabilized,and the activity of Ru BP and SPS increased 27.36%,35.51%.and the improvement effect showed a trend of increasing first and then decreasing with the increase of the substitution amount of organic fertilizer.Based on the photosynthesis and light response curves of potato leaves,the current study found that the net photosynthetic rate,stomatal conductance and transpiration rate of potato functional leaves increased first and then decreased with the increase of the application of organic fertilizer substitution.The best function of photosynthetic physiology was improved in the treatment of combination fertilization with 80%chemical fertilizer+20%organic fertilizer.4.The effects on nutrient absorption of potato plantsIn terms of potato nutrients uptake,reducing the application of chemical fertilizers and supplementing organic fertilizers can effectively increasing the accumulation of N,P,and K of potato tubers,increase the PFP,the apparent utilization of N,P,and K,the agronomic efficiency of N,P and K Productivity and nutrient utilization rate of NPK.5.Effects on potato yield and tuber qualityWith the increase of application of organic fertilizer,potato yield showed a trend of rising first and then decreasing.The higher potato yield can be observed in fertilization treatment of 80%fertilizer+20%organic fertilizer in all plots.Compared with the application of 100%fertilizer treatment,the average yield increased by 14.16%.In terms of yield composition,commercial potato rate,number of potato per plant and weight of potato per plant,the treatment of fertilizer supplementation with organic fertilizer was maintained effectively.In addition,the content of starch,soluble protein and vitamin C in potato tubers were significantly improved by adding 80%organic fertilizer+20%chemical fertilizer.