Effects Of Nitrogen Application Amount Occurrence Degree On Soil Biological Activity And Disease Of Potato Late Bright

In this study, potato grams New One as research material for potato rhizospheremicrobial quantity measured, while the potato rhizosphere urease, invertase, neutralphosphatase and catalase enzyme determined using PCR-DGGE (polymerase chainreaction-denaturing gradient gel electrophoresis) Determination of biologicalresearch means potato rhizosphere microbial richness and diversity of potato yielddetermined on the basis of the year, which was Nitrogen concentration in a reasonable,at the same time investigating the field of potato late blight disease degree for therealization of potato production practices to solve problems encountered in thefoundation, From the perspective of controlling disease to explore reasonable nitrogenlevel, but also to provide a reference for further research and rational application ofnitrogen fertilizer nitrogen nutrition of potatoes. The results shows that:(1) From the nitrogen level, different levels of nitrogen fertilizer on potato lateblight is significantly influence. No nitrogen treatment morbidity to a lesser extent,the yield is low; with the increase of nitrogen application, the extent of the diseaseincreased slightly, but the yield with the increase of nitrogen amount is increased;when the nitrogenous amounts to135kg hm-2level, the incidence to a lesser extent,yield is very high in nitrogen; In the nitrogenous amounts to higher level, diseaseseverity significantly heavier, also because of disease severely restrict result indecreased production. Potato tubers from large, medium and small potato allocationpoint of view, to promote the formation of nitrogen fertilizer in potato tuber, and withthe increase of nitrogen levels, the number of potato increases, nitrogen nutrient levelsalso contributed to the large increase in tuber weight thus directly contribute to theimprovement of production. From the production point of view, has an impact toohigh or too low nitrogen fertilizer on the yield of potato differences, when theoptimum nitrogen rate level (N5135kg hm-2), nitrogen-effective, but also the highestyield.(2) Different concentrations of nitrogen treatment, the number of bacteriaincreased with advancing growth period showed a single peak curve, seedling growth period began to tuber formation reaches a maximum and then drops to theaccumulation of starch, fungi growth period with an overall downward trend inadvance, changes in the number of actinomycetes bacteria similar, but the differenceis not very significant degree of change. Potato bacterial changes in various growthstages the highest rate, followed by actinomycetes, fungi, at least, show that bacteriaare the most sensitive to nitrogen. However, comparison between differentconcentrations of nitrogen treatment, the maximum rate of increase N5treatment,indicating that the bacteria, fungi and actinomycetes most sensitive to the amount ofnitrogen in the recommended treatment.(3) With the extension of the time after fertilization, soil urease and invertaseactivity showing a downward trend after the first increase, catalase activity showed agradual increasing trend, neutral phosphatase showed a slow decline further upwardtrend. After fertilizing the soil organic matter and humus increases over time willincrease, so the humus-related catalase will show a growing trend. And because thephosphatase activity directly affects the decomposition of soil organic phosphorustransformation so nitrogen fertilization on soil neutral phosphatase was not significant.Nitrogen concentration from the point of view of soil nitrogen moderate activity level（N4112.5kg hm-2、N5135kg hm-2、N6157.5kg hm-2）treatment was significantlyhigher than other nitrogen treatment, suggesting that the amount of nitrogen fertilizeron the enzyme activity to improve the most favorable, but not necessarily excessive orapplying a small amount Activation can achieve more satisfactory results.(4) Microbial diversity index downward trend overall is slow growth period withthe potato was advancing. Diversity index trends treated with different concentrationsof nitrogen and microbial number of different trends, namely the total number ofhigh-microbial treatment, microbial diversity index is not necessarily high. Amongthem, the amount of nitrogen fertilizer recommended N5microbial treatment is mostabundant, DGGE maximum optical density, the number of microbial communitiesimproved, increasing diversity, which is conducive to the growth of the potato.Through the different concentrations of nitrogen processing potato rhizospheremicrobial DGGE profiles richness, diversity and evenness analysis indices found in the potato tuber formation of microbial richness largest and highest evenness index.From the above results can be seen, in a certain level of nitrogen fertilization,with the increase of nitrogen amount, the number of soil microorganism inrhizosphere of potato, soil enzyme activity substances increases, when the amount ofnitrogen level for135kg hm-2, the maximum number of microbes, enzyme activitywas the strongest, the most abundant soil microbial diversity, high yield; when theamount of nitrogen (>135kg·hm-2), the number of microbes, soil microbial diversity,increased incidence, output falls. Therefore, from the improve the yield, to control atan optimal level of nitrogen.