Effects Of Combined Application Of Organic Fertilizer On Nitrogen Metabolism And Quality Of Flue-cured Tobacco In Different Ecological Regions

Mineralization and humification process of the organic fertilizer in the soil affect the effectiveness of nutrients,this process varies with different ecological environment,and the change of nutrients will inevitably affect the nutrient uptake,yield and quality of flue-cured tobacco.To study the difference of the response ability between flue-cured tobacco nitrogen metabolism and flue-cured tobacco quality in different climatic regions of Guizhou,Weining,Qianxi and Meitan were chosen to set up field experiments,respectively represent plateau moist subtropical monsoon climate region and Semiarid subtropical monsoon climate region.The transformation and metabolism of nitrogen in the "soil-flue-cured tobacco" system under different proportions of organic fertilizers have been studied.Nutrient transformation and microbial mechanism of effects of applying organic fertilizer on quality of flue-cured tobacco have been analyzed.The results showed that:(1)After applying organic fertilizer,soil organic matter in Weining was mainly synthesized and the content had increased,soil organic matter in Meitan was mainly decomposed and the content had reduced,Qianxi almost was unchanged.Among them,the content of organic matter was increased during the rooting period in three places,but the increase was different,which showed Meitan>Qianxi>weining.The soil organic matter in the Weining was up to the highest value during group period,Qianxi and Meitan reached the highest value during the rooting period.In the mature stage,the content of organic matter in the soil of these three places was higher than that of single fertilizer,and the proportion of organic manure was higher,and the content of organics was higher.(2)Application of organic fertilizer could significantly increase the number of soil microorganisms.In Meitan and Qianxi,the increase of bacterial quantity was more obvious than that of weining,which was consistent with the change of organic matter.There was no obvious change of soil microbial community structure in Weining,Qianxi and Meitan after applying organic fertilizer.However,there was a positive correlation between the abundance of thick-walled bacteria and the proportion of organic manure in soil mineralization.When the proportion of the application was 50%,the nitrifying bacteria in the soil nitrification bacterium had the highest abundance.(3)Organic nitrogen content increased by adding organic manure and increased with the amount of organic manure,but the proportion of organic nitrogen did not change significantly.The effect of organic fertilizer on inorganic nitrogen was great.The application of organic manure delayed the release time of inorganic nitrogen and improved the aftereffect of nutrients.The delayed time was expressed as Weining>Qianxi>Meitan.With the increase of the proportion of organic fertilizer application,the delaying effect was more obvious.The inorganic nitrogen was mainly caused by ammonium nitrogen in the rooting stage and the pellet stage,and the ammoniumnitrogen played a decisive role,but after the mad growing term,it was mainly determined by the change of nitrate nitrogen.The main component of inorganic nitrogen in the mature stage of Weining was ammonium nitrogen,while Qianxi and Meitan was nitrate nitrogen.(4)In Qianxi and Meitan,after transplanting and the mad growing term,soil nitrogen was sufficient.The effect of organic fertilizer on nitrate nitrogen in tobacco leaves was not significant,slightly improved in Weining tobacco.The soil nitrate nitrogen drops dramatically in the present bud.Nitrate content of tobacco leaves in Qianxi and Meitan decreased with increasing proportion of organic fertilizer.After the bud period,the NR of organic nitrogen substitution quantity in 50%,75% was high.Nitrate content of tobacco leaves was higher than other treatments in mature stage,Nitrogen uptake was still stronger.Compared with single fertilizer,there was no difference in ammonium nitrogen of tobacco leaf.(5)The direct reason for the decrease of nitrogen content in tobacco leaves was the weaken the supply of inorganic nitrogen because of the application of organic fertilizer in soil.Application of organic manure treatment reduced nitrogen content in tobacco leaves during group period and mad growing period in Weining,group period in Qianxi,and present bud period in Meitan.The nitrogen content of tobacco leaves was positively correlated with soil inorganic nitrogen,the correlation coefficients were 0.944,0.874,0.734.There was no correlation between nitrogen accumulation and nitrogen content in tobacco leaves.25% organic nitrogen in Weining,50% in Meitan and Qianxi ware the most favorable proportion to increase the nitrogen content and nitrogen accumulation in tobacco pre-middle and upper leaves during the mad growing period.(6)Organic fertilizer application had no blocking effect to the flue-cured tobacco growth in Weining.Application of organic nitrogen 100% treatment inhibited the growth of tobacco plant in Qianxi,application of organic nitrogen 75% and 100% treatment inhibited the growth of tobacco plant in Meitan,there was no effect with 25%,50%.The difference of tobacco composition between two ecological climates in tobacco-planting area was great.Reducing sugar and total sugar content performed as Weining>Qianxi>Meitan,Nicotine content performed as Meitan>Qianxi>Weining.Applying organic fertilizer increased N,K,sugar/alkali,reduced nicotine and chlorine,improved quality of tobacco leaves in Weining,the effect of applying organic nitrogen50% and 75% was good.The nitrogen content in tobacco leaves was low in Qianxi and Meitan.K,Nicotine and sugar/alkal were improved,quality of tobacco leaves was promoted,but security may be affected,when applied 75% organic nitrogen,there was the best effect on the improvement of tobacco leaf chemicals.Expect that combined application of organic nitrogen100% reduced leaf weight,output and output value,there was no differences between the remaining processes.The ratio of upper and middle class tobacco leaves increased in Weining and Meitan,good tobacco leaves ratio increased in Qianxi.Analyzed yield,quality and economic benefit of flue-cured tobacco,the proportion of organic nitrogen in 75% was the best in Weining,Meitan and Qianxi were the best in the proportion of 50%.