Effect Of Fertilizer On The Improvement Of Newly Consolidated Tobacco Yellow Field

Chongqing is one of the main tobacco producing areas in China,tobacco growing area is maintained at 40000~46667 hectare,planting scale and output accounted of tobacco is listed as the sixth place in China,which is a typical mountain agricultural ecological zone.In order to promote the modernization of tobacco fields,improving the degree of mechanization,combined with the characteristics of large area of tobacco planting area,the larger slope of farmland,it is imperative to carry out land consolidation of basic tobacco fields.However,in the process of tobacco field consolidation,the soil fertility was decreased,the yield and quality of tobacco leaves were decreased due to the disturbance of large machinery.Therefore,through the study on the effect of fertilization on tobacco soil and tobacco curing quality,and then select the optimum fertilization model,the research on comprehensive evaluation of soil fertility in tobacco fields was carried out,which provided the basis for the healthy and sustainable development of tobacco industry.In this experiment,the main city of Chongqing tobacco District new finishing tobacco field as object,combined the field study with laboratory test study of bio organic fertilizer on the whole new soil microbial ecological characteristics;influence of bio organic fertilizer on tobacco field soil fungal community structure and the quality of tobacco;effect of humic organic fertilizer bentonite composite acid yellow soil conditioner on nitrogen adsorption;new consolidation soil fertility comprehensive evaluation,the main results are as follows:(1)different fertilization patterns(conventional processing,bio organic fertilizer 375 kg/hm2,750 kg/hm2 bio-organic fertilizer and biological organic fertilizer 1500 kg/hm2)influence on the economic benefits of tobacco,tobacco quality,soil microbial number and activity are different.Compared with the conventional treatment,for three consecutive years of biological organic fertilizer treatment,the average price,the total output value and the proportion of superior tobacco were improved,with 750 kg/hm2 bio-organic fertilizer treatment the average price,the proportion of superior tobacco and the highest total output value;compared with the conventional treatment,bio organic fertilizer 750 and 1500 kg/hm2 treated soil microorganism quantity,soil microbial biomass carbon,soil microbial respiration and microbial quotient were improved to a certain extent,combined with the flue-cured tobacco production,biological organic fertilizer 750 kg/hm2 is the best choice.(2)The tobacco field of yellow soil for three consecutive years of fixed bio organic fertilizer,can improve the soil of tobacco field soil fungal community structure,tobacco fungal community diversity increased.The application of bio organic fertilizers,the soil fungi in the Ascomycota group beneficial Sordariales_unclassified and Hypocreales increase in relative abundance with the pathogenicity of Gibberella relative abundance decreased,while the other Zodiac little variation in abundances of bacteria.Tu Hui with bio organic fertilizer and phosphorus fertilizer application reduced the incidence of tobacco,increase the yield and quality of tobacco leaf proportion.The tobacco field soil fertilizer recommendation based biological organic fertilizer 675 kg/hm2 with 1500 kg·hm-2 in transplanting nutrient soil(by 1372.5,Tu Hui biological organic fertilizer,compound fertilizer and phosphate fertilizer 75 15 37.5 uniform mixture)fertilization method.(3)the structure and diversity of the fungal communities in yellow-soil tobacco field improved after the application of biological organic fertilizers for three consecutive years.Compared with the traditional approach,application of biological organic fertilizers increased the relative abundance of the beneficial orders Sordariales and Hypocreales,from the class Sordariomycetes,among the dominant fungal communities in the soil;and decreased the relative abundance of the pathogenic Gibberella genus.Whereas the relative abundances of other fungal genera did not change significantly.Application of biological organic fertilizers in combination with ash and phosphate fertilizer decreased the disease incidence in tobacco,increased the tobacco yield,and raised the percentage of intermediate and superior tobacco.The basal application of biological organic fertilizers at 675 kg/hm2 combined with drill-hole application of nutritional soil at 1500 kg/hm2(composed of well mixed ash 1372.5,biological organic fertilizers 75,and phosphate fertilizer 37.5)is recommended for yellow-soil tobacco fields.(4)To a certain degree of improvement of fuzzy comprehensive evaluation method,using the fuzzy mathematics method to determine the membership degree of evaluation index,calculate the weight by partial correlation coefficient method,the soil fertility quality of Chongqing tobacco field before and after finishing the modified comprehensive evaluation.Select 11 indicators as evaluation indicators,including: water stable aggregate structure,pH,cation exchange capacity,organic matter,total nitrogen,total phosphorus,slow acting potassium,alkali hydrolyzable nitrogen,available phosphorus,available potassium,water-soluble chlorine.The contribution of each evaluation index of soil nutrient,the largest contribution to soil nutrient is the organic matter,the weight coefficient is 0.1657,and the contribution of the smallest is k,the weight value is only 0.0244.After the improvement of tobacco field,the level of nutrient fertility(IFI)was very high,accounting for 5.21% of the total,and the high level of nutrient fertility accounted for about 46.96%,and the nutrient level was moderate,and the nutrient level was low and extremely low,accounting for only about 6.4%.The key indexes of soil fertility before and after the improvement of tobacco fields in Chongqing were greatly changed.On the whole,the soil fertility was improved significantly.Among them,the amount of available nutrients,total nutrients,cation exchange capacity and the number of microbial flora in the soil were greatly improved.Improvement effect is obvious.