Effect Of Potato’s Continuous Cropping And Diversity Regulation On Soil Microorganisms

In order to alleviate potato’s continuous cropping obstacles and seek the most suitable intercropping types in the south area of Ningxia province, three part of contents was studied by the methods of BIOLOG, PLFA et.al:one is the condition of the soil fertility and the soil microorganisms’s diversity under continuous cropping by taking different continuous cropping years as the objects; the other one is the change of soil fertility and soil microorganisms’diversity under the control of different intercropping types(potato/corn, potato/broad bean); and the last one is the soil fertility and the soil microorganisms functional and structural diversity in greenhouse. The main result showed:1. In the condition of continuous cropping, the soil fertility showed a rise and then drop trend along with the continuous cropping years, pH is the highest in10th year, and higher0.62%,1.37%and1.37%than2nd,4th and10th year; the organic matter also decreased along with the years. The number of soil microorganism was dropped, and showed4th year>2nd year>10th year>6th year, the spore density and metabolic activity showed in the similar way. And we had identified AMF4classes and54species, the dominant species in each treatment showed:G.delhiense.Gformosanum in2th year, Gdeserticola,G.geosporum in4th year, G.formosanum,G.geosporum in6th year and Gglobiferum in10th year.2. In the condition of intercropping, treatments, especially potato/broad bean, raised the soil fertility, and improved AP,AK49.86%、27.41%significantly than CK.16:1ω5c、i16:0and18:1ω9c was the most in the14PLFAs, and had a portion of20.20%,17.26%and34.32%respectively. And there’s also an improvement in AWCD. We found AMF4classes43species, and the dominant species showed:Glomus clarum, G.geosporum in CK; G.formosanum,Acaulospora tuberculata in the treatment of potato/corn; and G.formosanum,G.globiferum in potato/broad bean.3. In the condition of intercropping and inoculating of AMF(G. Etunicatumon), the microorganisms in each treatment, especially potato/corn, showed bacterial dropped, actinomycetes grown, and fungus had no changes. The metabolic activity of the soil microorganisms grew in some degree, and had a strong ability in using the carbon compounds and amino, the AWCD in96h was higher9.41%、12.19%than CK.4. The factors affect the diversity of AMF showed:The diversity of AMF was mainly affected by the available phosphate, available potassium, pH. And the diversity of AMF in the condition of intercropping was affected by the soil’s available fertility, the pH and the microorganisms’ structure and function. The intercropping and inoculating of AMF had an overlapping effect on the diversity of AMF.