Effects Of Soil Amendments On Rhizosphere Properties OfDifferent Genotype Tartary Buckwheat Under Continuous Cropping

Buckwheat continuous cropping obstacles has become one of the major limiting factors for increasing yield. For the practical problems,in this study we used two large-scale cultvivated different genotype tartary buckwheat varieties( Chuanqiao 1 and Xiqiao 1) under cropping continuous as materials to understand three kinds of soil amendments on tartary buckwheat root morphology,root secretion of organic acids,rhizosphere soil characteristics,microorganism,traits and yield. The main results were as follows: 1 Study on relationship between continuous crop Tartary buckwheat root morphology of seedling and filling and its yieldAfter continuous cropping,tartary buckwheat seedling root exudated malic acid content and grains per plant,tartaric acid content and grain weight,oxalic acid content and seed weight per plant,citric acid content and seed setting rate,and rhizosphere bacteria and kernel weight,grain weight per plant and the number of fungi,actinomycetes and grain weight per plant,cotyledon node height and height per plant,grain weight per plant and main stem node number and one hundred weight,the number of branches and the main stem per plant and seed rate showed a significant positive correlation. Although other conditions and yield formation index were positively correlated also,but it did not reach significant levels. The filling of organic acids in root exudates,rhizosphere microorganisms and agronomic traits and yield formation indicators showed a significant(p<0.05) positive correlation,the difference was significant.2 Effect of soil amendments treatment on the root morphology and organic acidsSoil amendments could significantly reduce root length,surface area, volume,the number of nodes and tips of continuous cropping tatary buckwheat.The inorganic soil amendments affected most significantly, which decreased the root index by 18.39%,13.22%,29.07%,25.76% and 14.41%,and the organic soil amendments have less effects. After applying soil amendments,two kinds of continuous tartary buckwheat root exudated organic acid showed the same trend. Compared with CK,the malic acid,tartaric acid,oxalic acid and citric acid content in a series of treatment Tartary buckwheat reduced by2.74%-63.49%,24.73%-95.77%, 15.07%-94.03%,and15.22%-88.00%,respectively.The organic soil conditioner affected most significantly,inorganic soil conditioner have less effects.3 Effect of soil amendments treatment on the rhizosphere microorganismsSoil conditioner could significantly increase the number of continuous cropping Tatary buckwheat rhizosphere microorganisms.Compared with CK,the bacteria,fungi,actinomycetes,azotobacter,denitrifying bacteria, nitrifying bacteria and thiobacillu increased by12.62%-39.83%,3.92%-22.34%,69.79%-111.41%,8.13%-19.50%,8.13%-19.50%,28.18%-46.64% and 17.94%-77.97%,respectively.There were significant differences between all the treated and CK,organic amendments treatment showed the most significant effects,and inorganic soil conditioner had less effect than other treatments.4 Effect of soil amendments treatment on the rhizosphere soil propertiesCompared with CK,the two continuous Tatary buckwheat rhizosphere soil water content,field capacity,relative water content,conductivity, organic matter and p H under three soil amendments treatment increased by 1.66%-26.70%,2.85%-29.97%,1.63%-26.33%,1.56%-16.67%, 27.02%-43.22% and 0.36%-2.11%,respectively. Each treatment groups differed significantly in comparation with CK. Organic amendments treatment affected more than other treatments,and inorganic soil conditioner showed lest effect. Under organic soil amendment treatment,two continuous tartary buckwheat rhizosphere index including total nitrogen,total phosphorus,total potassium,nitrogen and effective phosphorus significantly increased by 36.58%,86.99%,6.26%,49.29%and 79.05%,respectively. The differences between other four treatments(continuous cropping,normal,mixture soil amendments, inorganic soil amendments)were not significant.5 Effect of soil amendments treatment on the agronomic traitsSoil amendments could impact the agronomic characters index of two continuous Tatary buckwheat. Compared with CK,plant height,cotyledon node height,nodes per plant,main stem number of branches and main stem diameter under organic soil amendments treatment,significantly increased by 11.61%,22.16%,10.09%,16.67%and14.2%,respectively. The difference between other four treatments was not significant.6 Effect of soil amendments treatment on yieldCompared with CK,the grains per plant and grain weight per plant,kernel weight,strong rate,polyphenols content and protective enzyme content of continuous Tatary buckwheat treated by soil conditioner increased by 21.73%-88.50%,11.76%-94.51%,1.18%-38.34%,4.76%-40.32%,26.92%-234.78%,and 2.79%-23.22%,respectively. There was significant differences between all the treatments and CK,the organic amendments treatment demonstrated more significant effect than other treatments did,and mixed soil conditioner showed less effect than other treatments did.