Yulin area is a high quality potato growing area in arid and semi-arid areas of our country.At present,the development of potato industry in Yulin area gradually tends to be slow,mainly because of the large number of potato varieties.It is difficult to select potato varieties suitable for this region with better economic and social benefits.The aim of this study was to investigate the mechanism of soil nutrients on the yield and quality of potato tuber in Yulin area.The key factors influencing soil nutrients on yield and quality of different potatoes were determined.The interaction of soil nutrient factors in root zone of different varieties of potato in this area was revealed to affect the high yield and high quality of potato.In order to provide theoretical basis and technical support for better potato screening in Yulin area.In this study,15 major potato varieties(Atlantic,Zhongshu 28,1025,Longshu 7,Zhongshu 27,Qingshu 9,Jizhangshu 12,Qingshu 7,Jinshu 16,Kexin 19,Zhongshu 18,Zhongshu 3,Longshu 6,Longshu 11,and Xingjia 2)were selected from Yulin area.Through field experiments,the differences of tuber yield,quality and soil nutrients of different potato varieties were analyzed and compared.The distribution of soil nutrients in root zone of different varieties of potato and their interaction with soil nutrient factors were studied.The regression equation between potato quality and soil nutrient content was established.The effect of soil nutrients on the yield and quality of potato tuber was revealed,and the varieties suitable for regional characteristics were screened by membership function method.The main research findings are as follows:(1)The soil moisture content,electrical conductivity,and nitrate nitrogen content showed a trend of first increasing and then decreasing in the 0-60 cm soil layer,but the trend of p H value change was opposite;The content of soil available potassium,available phosphorus,alkaline nitrogen,and organic matter decreases with the increase of soil depth.Among the tested varieties,Longshu 7 had the lowest soil nitrate and alkaline nitrogen content,lower available phosphorus and potassium content,and higher soil organic matter content at 4.71 g/kg,with the highest soil catalase activity.The activities of soil catalase,urease,sucrase,and alkaline phosphatase all decrease with the increase of soil depth.However,the soil enzyme activities in the 0-20 cm soil layer and the 20-40 cm soil layer are not significantly different,but are significantly higher than those in the40-60 cm soil layer.The correlation analysis results show that the activities of four enzymes in the soil are highly significantly positively correlated with the content of soil organic matter.In addition,the activities of soil urease,alkaline phosphatase,and sucrase are also significantly positively correlated with the content of nitrate nitrogen,alkaline hydrolyzable nitrogen,available phosphorus,and available potassium in the soil.There is a significant correlation between soil moisture content,p H value,electrical conductivity,and nitrate nitrogen content with yield and quality.The content of soil alkali hydrolyzed nitrogen,available phosphorus,available potassium,and organic matter did not significantly affect yield and quality.(2)The yield distribution of the tested potatoes is 26.60-89.14 × 10~3 kg/hm~2,variety Qingshu 7 has the highest yield of 89.14 × 10~3 kg/hm~2,significantly higher than other varieties(excluding Zhongshu 28 and Kexin 19),and the yield of Kexin 19 is also relatively high,at 80.71 × 10~3 kg/hm~2;The starch content and total soluble sugar content of the tested potatoes were distributed between 1.89%-11.49% and 0.94%-3.57%,respectively.Among the varieties,Shu 18 had the highest starch content and total soluble sugar content,and had significant differences in starch content compared to varieties1025,Zhongshu 18,Longshu 6,and Xingjia 2.However,there was no significant difference in total soluble sugar content among the tested varieties(except for Jizhangshu 12 and Longshu 6);The crude protein content and total potassium content are distributed at 0.025 mg/g-0.104 mg/g and 3.2 mg/g-4.87 mg/g,respectively,with variety Longshu 6 having the highest content;The Mass distribution of tuber dry matter was15.44%-23.44%,and Longshu 11 was higher than other varieties;The content of reducing sugar in tubers ranges from 0.16% to 0.71%,with the highest content in variety Shu28,which is significantly higher than the other 14 varieties;The total phosphorus content ranges from 0.68 mg/g to 1.10 mg/g,with the highest content being Jinshu 16,which is 1.10 mg/g.There is a significant difference between Jinshu 16 and Atlantic,Zhongshu 28,1025,Qingshu 9,Qingshu 7,Zhongshu 3,Longshu 11,and Xingjia 2.The vitamin C content is distributed between 5.50 mg/100 and 12.88 mg/100 g,with variety1025 having the highest content and significantly higher than other varieties.The starch processing of potato seeds requires a starch content of ≥ 15% in potato tubers,and all15 varieties tested are lower than the requirements;The potato varieties for frying and whole flour processing require a reduced sugar content of less than 0.4% and a dry matter content of more than 20%.Therefore,the varieties Atlantic,1025,Qingshu 9,Jizhangshu12,Qingshu 7,Jinshu 16,Longshu 6,and Longshu 11 are suitable for frying and whole flour processing purposes.(3)Through VIP(Variable Importance Projection Method)screening,it was found that potato yield and total soluble sugar content in tubers are most affected by catalase activity,reducing sugar content in tubers is most affected by soil p H,crude protein content in tubers is most affected by soil alkaline nitrogen content,vitamin C content,total phosphorus content,and dry matter content in tubers are most affected by soil moisture content,and starch content in tubers is most affected by soil urease activity,The total potassium content of tubers is most affected by soil sucrase activity.Therefore,soil nutrients are regulated to varying degrees based on the role and value of potatoes,in order to fully leverage the quality advantages of each potato variety.(4)Based on the comprehensive evaluation results,the average membership function values of various quality indicators of different varieties are calculated and comprehensively sorted to obtain:Qingshu 7(0.632)>Longshu 7(0.626)>Longshu 6(0.620)>Longshu 11(0.616)>Jinshu 16(0.616)>Kexin 19(0.606)>Atlantic Ocean(0.602)>Zhongshu 27(0.581)>Jizhangshu 12(0.560)>1025(0.557)>Xingjia 2(0.553)>Qingshu 9(0.501)>Zhongshu3(0.476)>Zhongshu 18(0.391)>Zhongshu 28(0.340)Among them,the average membership function values of varieties Longshu 7 and Jinshu 16 are ranked higher,and they absorb soil nutrients comprehensively,making them less prone to residual nutrients;The varieties Qingshu 7 and Kexin 19 have higher yields and larger membership function values,which belong to the varieties with better yield and quality,and have many benefits for the development of the local potato industry.If we comprehensively consider prioritizing yield and quality in the development of agricultural economy,we can consider promoting the planting variety Qingshu 7;If the soil environment and sustainable development are comprehensively considered,the variety Longshu 7 can be promoted and planted. |