Effects Of Long-Term Fertilization On Soil Fertility And Microbial Diversity Of Continuous Cropping Peanut

Peanut is an important economic crop and oil crop in China.It has the characteristics of resistance to barren and drought resistance.The semi-arid areas in the northwestern part of Liaoning Province are mostly sandy soils,the soil texture is coarse and the nutrient content is low,and the sandy soils are barren compared with other soils.Peanuts are one of the main drought-resistant crops in the northwest of Liaoning,and the planting area is expanding and the area of continuous cropping increases,peanut continuous cropping caused serious losses.Regional factors and continuous cropping obstacles seriously threaten the development of peanut planting industry in northwest Liaoning.In this paper,the study was based on the sand soil fertilizer and continuous cropping positioning test,set up eight processing:CK,N,NP,NPK,M,MN,MNP,MNPK and explore different fertilization systems on sand soil fertility of soil,the influence of the enzyme activity,microbial diversity and the influence of yield and growth of peanut continuous cropping,the main results were as follows:(1)The effect of long-term fertilization on soil nutrient content and soil physical condition was improved.Fertilizers and organic fertilizers increased the contents of total N,available N and available P,available K and organic matter in soils,but had little effect on total potassium content.The effect of MNPK on the content of organic matter was the best,and the effect of MNPK was the best in increasing total nitrogen and available nitrogen,available phosphorus and available potassium.The soil bulk density of all fertilization treatments was less than that without fertilization,and MNPK had the lowest soil bulk density.It can be seen that the combination of chemical fertilizers and organic manure has a positive effect on reducing soil bulk density and increasing soil available nutrient content.(2)Fertilization could increase the activities of urease,sucrase and acid phosphatase in plow layer,and the chemical and organic fertilizer were significantly higher than those of chemical fertilizer only.Compared with single application of nitrogen fertilizer,the application of phosphate and nitrogen fertilizer could significantly increase the activity of acid phosphatase and sucrase in plow layer,and the soil enzyme activity was significantly higher than that of single application of nitrogen fertilizer.Compared with nitrogen and phosphorus treatment,the application of nitrogen phosphate and potassium fertilizer could significantly increase soil urease activity,indicating that NPK balanced fertilization was of great significance to improve soil enzyme activity.The activities of soil urease,acid phosphatase and invertase were positively correlated with soil total nitrogen,total nitrogen,total phosphorus,available phosphorus,available potassium and organic matter(p<0.01).(3)Long-term fertilization had a seasonal effect on the microbial diversity of sandy soil but had no significant effect on its uniformity.From the point of view of peanut harvest,fertilization significantly improved the diversity of bacterial communities in the sandy soil,especially the long-term application of organic fertilizer;fertilization improved the diversity of fungi communities in the sandy soil,but there was no fixed law.(4)Fertilization had different effects on the microbial community of sandy soil.The effect of organic manure on the structure of bacteria and fungi was higher than that of chemical fertilizer.(5)Different fertilization treatments had different effects on peanut growth and yield.The height of the main stem of the peanut and the length of the first branch were significantly higher than those without fertilization,and the effect of fertilizer and organic fertilizer were better.Compared with non-fertilization treatments,the yield of all fertilization treatments was significantly increased.NPK and MNPK treatments had the best effect in their fertilization structures by increasing yield.There was a significantly positive correlation between peanut yield and soil total nitrogen,total phosphorus,available nitrogen,available phosphorus,available potassium,soil urease,sucrase and acid phosphatase activity during the harvesting stage(p<0.01).(6)The microbial diversity,soil enzyme activity and peanut yield were positively correlated with soil available nitrogen,total phosphorus,available phosphorus and available potassium,and negatively correlated with soil bulk density.The bacterial diversity was almost independent of soil pH,and the diversity of fungi was negatively correlated with soil pH.The main factors affecting the type of bacteria in the sandy soil were soil alkali nitrogen,total nitrogen,total phosphorus,available phosphorus,available potassium and total potassium.The main factors affecting the type of fungal in the sandy soil were soil alkali nitrogen,available phosphorus,organic matter and pH.