The Study Of Improving Yellow Soil Fertility In Newly Consolidated Tobacco Field

Chongqing is one of the key tobacco growing areas in China,and the tobacco land is mainly located in the mountains and hills with altitude of 600 ~1300 M.In recent years,in order to meet the demand of tobacco production and improve the mechanization rate of tobacco field,land consolidation activities were carried out in Chongqing.But the physical,chemical and biology properties of consolidated tobacco soil deteriorate.Suitable soil conditions are the basis for high-quality tobacco production,in order to improve the soil fertility and tobacco economic benefit of tobacco field after finishing.In this experiment,combination of field experiment and laboratory experiment,the effect of biological organic fertilizer and phosphate fertilizer application on bacterial and archaea community in new land consolidation yellow soil,and application effects of wide-narrow ridge corp rotation on soil physical and chemical properties,and proportion of fulvic acid potassium and rate of soil conditioners on soil potassium absorption characteristics were investigated.The main results are as follows:(1)Archaea community of newly consolidated tobacco-planting soil was composed of Thaumarchaeota,Euryarchaeota and Archaea_unclassified.Three years application of biological organic manure increased the number of archaea and bacterial community diversity,and chloroflexi,nitrospira,proteobacteria and the relative abundances of51.4 of bacteria genera and the relative abundances of 76.5% archaea genera were higher than those of traditional fertilizer treatment alone.Application of bio-organic fertilizer led to more evenly distributed bacterial and archaea,which is conducive to stabilize soil microbe ecosystem,and combined application of biological organic manure with phosphorus fertilizer made better results.(2)The improvement of the bacterial and archaea community structure in tobacco fields significantly increased the yield,the economic efficiency of flue-cured tobacco was significantly improved.For newly consolidated tobacco-planting soil,application of biological organic manure and rhizosphere nutrient soil can be used to improve the soil quality,to increase the soil archaea community diversity and tobacco yield and quality.On the basis of comprehensive benefits,for the new finishing yellow soil application it was recommended biological organic fertilizer 675 kg/ha with improved rhizosphere soil 1500 kg/ha(1372.5 kg ash soil,75 kg biological organic fertilizer,15 kg compound fertilizer,and 37.5 kg phosphate fertilizer mixing).(3)The wide-narrow ridge planting pattern's soil temperature decreased by 0.8 ~5.5 ? during the high temperature period;The net photosynthetic rate in vigorous growing stage increased by 12.15% than that of the uniform ridge;Wide-narrow ridge planting pattern also improved soil enzyme activities and soil nutrient content,which played an important role in soil improvement.The wide-narrow ridge combine of 20%organic nitrogen fertilizer and furrow straw mulching had better benefits,which soil temperature decreased by 25% than that of uniform ridge on July 19 th,the net photosynthetic rate increased by 13.37%,and the average activities of four enzymes were increased by 13.15%,12.49%,19.82% and 9.58%,respectively.Wide-narrow ridge as a new planting technique has a good effect on soil improvement,with the application of 20% organic nitrogen base fertilizer and straw mulching furrow is better.(4)The effects of soil conditioner on soil adsorption of K+ with prolonged incubation time showed a gradually increasing trend.The isothermal adsorption curves of K+ can be well fitted by Langmuir equation.With the increase of soil conditioners,soil K+ the maximum adsorption capacity of Qmax increased gradually.On the premise of the same amount of application,the K+ adsorption capacity was best when the dosage of fulvic acid potassium was 20%,the ratio of fulvic acid potassium was more than 20%,the effect of Qmax is weakened and may cause the risk of soil potassium loss.Results showed that the retention of soil conditioner on soil K+ has obvious role in promoting,the proportion of fulvic acid potassium in the modified material with 20% best.