Research On Different N Use Efficiency Of Cucumber Cultivars On Rhizosphric Soil Ecosyste Properties

With the vigorous development of facilities horticulture industry, applying nitrogen content arerising, which brings negative effect also appeared slowly, on the ecological environment and the life ofpeople brought bad influence. To alleviate or solve the excessive nitrogen fertilizer, many researchscholars have in-depth research on crop nitrogen efficiency. Cucumber is one of the kinds of facilitieshorticulture cultivars, to study the characteristics of different the nitrogen efficiency cucumber varieties,and to promote the cultivation of nitrogen-efficient cucumber varieties, can alleviate the problem of toomuch nitrogen fertilizer, also bred morenitrogen as a theoretical basis for efficient cucumber varieties.In this paper,rhizosphere soil of cucumber cultivars to different nitrogen efficiency under differentnitrogen main object of study, combined with the cucumber shoot growth of different nitrogen forms onthe different nitrogen efficiency cucumber varieties rhizosphere microbial community structure,quantity, andsoil enzyme activities and microbial biomass.The late seedling growth index the differentnitrogen efficiency cucumber varieties, morphological character of roots and rhizosphere soilnitrification properties and ammoniated characteristics change research. Designed to reveal the differentnitrogen efficiency cucumber varieties Growing status and differences in rhizosphere soil ecologicalenvironment and provide a theoretical basis for the screening of different nitrogen efficiency cucumbervarieties, improve nitrogen use efficiency and production practice cucumber varieties selection.Throughtesting the main results are as follows:1. Nitrogen efficient varieties of cucumber plant height under nitrogen and normal nitrogenconditions were lower than N inefficient plant height of cucumber varieties. Nitrogen efficientcucumber leaf area was significantly greater than in the seedling stage nitrogen inefficient cucumbervarieties after planting in nitrogen inefficient cucumber varieties. Under normal nitrogen and lownitrogen stress condition, the nitrogen efficiency of cucumbern seedings varieties of root length, rootsurface area, root volume, root number, root average diameter and root dry weight were higher than ninefficient cucumber varieties. Root diameter in the range0＜D≤0.5mm, in normal n and low ncondition, the nitrogen efficient varieties of cucumber seedlings root length, root surface area werehigher than n inefficient cucumber varieties.2. The cucumber after planting40d, under nitrogen conditions, nitrogen efficient varieties ofcucumber always maintained a high rhizosphere soil protease activity, catalase activity, neutralphosphatase activity, and lower soil nitrate reductase activity. 3. Cucumber engraftment after40d, normal nitrogen under the conditions of different nitrogenefficiency of cucumber varieties of rhizosphere bacteria, fungi, and the number of ammonifying bacteriaand actinomycetes were higher than in nitrogen conditions; Under the condition of no nitrogen, nitrogenefficiency of cucumber varieties of rhizosphere soil is significantly higher than the number ofammonifying bacteria n inefficient cucumber varieties. The nitrogen efficient varieties of cucumberseedlings rhizosphere soil ammonifying bacteria, denitrifying bacteria, ammonification intensity weresignificantly higher than n inefficient cucumber varieties.4. Under normal nitrogen and low nitrogen stress condition，nitrogen efficiency of cucumber G2rhizosphere soil AOB community size were higher than in nitrogen low-efficient cucumber.5. Nitrogen efficiency of cucumber varieties of rhizosphere bacteria and ammonia-oxidizingbacteria community structure under the condition of no nitrogen instead of normal nitrogen under thecondition of rhizosphere bacteria community structure is different, and nitrogen efficiency of cucumberG2rhizosphere bacteria DGGE graph stripe number and diversity index were higher than in nitrogenlow-efficient cucumber varieties. In cucumber engraftment after40d, not normal nitrogen and nitrogenapplication condition, the nitrogen efficient varieties G1rhizosphere ammonia oxidizing bacteria DGGEprofiles on the number of bands cucumber varieties were higher than in nitrogen and low D1.Under thecondition of no nitrogen, nitrogen efficiency of cucumber G1rhizosphere fungi DGGE profiles on thenumber of bands are more than n inefficient cucumber varieties.Voreall, Cucumber plant height, leaf area and root length and root surface area in seedling periodof change also can be used as a nitrogen efficiency of cucumber varieties screening.40d and60d aftercucumber engraftment, namely the cucumber growth anaphase, different nitrogen efficiency ofcucumber varieties large changes have taken place in rhizosphere soil ecological environment, andnitrogen efficiency of cucumber varieties rhizosphere ecological environment change than nitrogenlow-efficient cucumber varieties, this shows that the nitrogen efficiency of cucumber varieties canthrough adjusting their rhizosphere soil enzyme activity and microorganism quantity and microbialcommunity structure so that it is to elevate the ability of nitrogen absorption use.