Effects Of Several Common Chemical Fertilizers And Their Different Amount Of Fertilizer On Activity Of Tobacco-Planting Soil And Flue-Cured Tobacco Production

The long-term heavy application of chemical fertilizers has caused problems in the quality and yield of flue-cured tobacco which has severely affected the healthy development of the tobacco industry in China.This project studied and analyzed the effects of long-term heavy application of chemical fertilizers on the activity of tobacco-planting soil from three aspects of laboratory simulation tests,long-term experiment,and field production.Laboratory simulation experiment was conducted with 10 years of tobacco-planting fallow soil as test soil and 9 kinds of chemical fertilizers that commonly that used in tobacco production.Each fertilizer was set with 5 different fertilization concentrations and repeated 5 times.A total of 230 pots of test soil was cultured under simulated natural conditions at 20? and 65%humidity in the artificial climate chamber.Samples were taken at intervals of 4,8 and 12 days from each fertilization.A total of 18 batches(4140 samples)of samples were obtained.The soil microbial activity(soil respiration),soil microbial functional diversity(acid phosphatase,catalase,and urease)were measured,and soil microbial community structure and community diversity were analyzed using high-throughput sequencing methods.Long-term experiment and field production were designed as five the fertilization measures and four amounts of fertilizer applied were respectively designed at the Longgang and Fuquan bases of Guizhou Academy of Tobacco Science.The analysis of tobacco yield,quality,agronomic traits,soil microbial communities were studied to determined the effects of fertilization system and fertilizer amount on the production of flue-cured tobacco.The results of the study are as follows:1 Laboratory simulation test results show:(1)Different chemical fertilizers have significant effects on soil respiration.The effect of urea treatment on the respiration intensity of tobacco-planting soil was obvious,and it had a good regularity.The respiration trend was 50%,100%and 150%increase of the conventional fertilizer application>conventional fertilization treatment>50%reduction of the conventional fertilizer application.In particular,at 88 days,soil respiration of urea treatment was 1.65-3.96 times higher than that of the control treatment(CK);K2SO4,KCl,and KNO3 treatment significantly increased soil respiration at 20-40 days after fertilization;The soil respiration of monoammonium phosphate treatment was inhibited at 84 days after fertilization.The other treatments had no significant effect on soil respiration.(2)Different chemical fertilizers have a diverse effect on soil enzyme activity.The inhibitory effect of monoammonium phosphate on acid phosphatase was obvious.The inhibitory effect of alkaline fertilizer on acid phosphatase was urea>compound fertilizer for flue-cured tobacco and calcium magnesium phosphate fertilizer.Fertilizers containing nitrate nitrogen and potash fertilizers had significant effects,while calcium superphosphate had no significant effect.Acid fertilizers(calcium superphosphate and monoammonium phosphate)had a significant inhibitory effect on catalase,while alkaline fertilizer(urea,calcium magnesium phosphate fertilizer)had no significant effect on catalase as follows calcium superphosphate and monoammonium phosphate>potassium nitrate and compound fertilizer for flue-cured tobacco>potash fertilizer and ammonium nitrate>urea and calcium magnesium phosphate fertilizer.After 60 days,the activities of catalase with different calcium superphosphate fertilization rates were:50%reduction treatment>conventional fertilization treatment and 50%increase treatment>100%increase treatment and 150%increase treatment.Fertilizers containing ammonium nitrogen had a significant inhibitory effect on urease activity.Phosphorus fertilizer could significantly reduce soil urease activity,Potassium fertilizer could significantly promote urease activity.The overall trend was that potassium sulfate>potassium chloride.The effect of potassium nitrate on urease activity was not significant,after 64 days.The activities of urease with calcium magnesium phosphate fertilizer different fertilization rates were:50%reduction treatment and conventional fertilization treatment>50%increase treatment>100%increase treatment and 150%increase treatment.(3)Different chemical fertilizers have a significant effect on the dominant population of soil microbial.Through high throughput sequencing analysis,the nine dominant phylam are Actinobacteria(18.52%-84.03%),Proteobacteria(3.13%-39.49%),Acidobacteria(2.118%-18.89%),Chloroflexi(2.456%-11.16%),and Firmicutes(urea treatment is 20.97%-69.36%,others 0.17%-4.63%),Nitrospirae(0.49%-3.85%),Gemmatimonadetes(0.33%-3.71%),Bacteroidetes(0.22%-21.29%),Planctomycetes(0.26%-1.77%),the proportion of which is 96.96%-99.169%.Actinobacteria is the largest dominant phylum among the dominant phyla.The relative abundance of Actinobacteria is ranked as:compound fertilizer>phosphate fertilizer>potash>nitrogen fertilizer.The relative abundance of Proteobacteria is ranked as:potash>fertilizers containing ammonium nitrogen>phosphate fertilizer.The relative abundance of Acidobacteria is ranked as:potash>fertilizer of containing nitrate nitrogen>phosphate>fertilizers of containing ammonium nitrogen(in addition to ammonium nitrate).The relative abundance of Nitrospira is ranked as:fertilizer of containing nitrate nitrogen>potash fertilizer>urea>fertilizer of containing phosphorous.The relative abundance of Firmicutes is ranked as:fertilizers of containing ammonium nitrogen>potash fertilizer>phosphate fertilizer.(4)Long-term heavy application of chemical fertilizers has a significant effect on soil bacterial community diversity.Through high-throughput sequencing analysis,fertilizers of containing ammonium nitrogen(monoammonium phosphate,special compound fertilizer for flue-cured tobacco,urea,and ammonium nitrate)had significant inhibitory effects on soil bacteria community diversity.The treatment of potassium sulfate,potassium nitrate,calcium superphosphate,ammonium nitrate,calcium magnesium phosphate fertilizer were less significant.And potassium chloride reducing the application of 50%and increasing the application of 50%treatment were not significant.At the same time,with the increase of fertilization concentration,the inhibitory effect of chemical fertilizers on soil bacteria diversity increasesd.Except for 50%reduction application and 50%increase application of potassium chloride,other chemical fertilizers and different fertilizing amount had serious inhibition on soil bacterial community diversity,accounting for only 56.42%-93.73%of control(CK).2 Field test results show that:From different fertilizer measures(Longgang Long-Term Positioning Test):The balanced and comprehensive application of fertilizers on the yield and quality of flue-cured tobacco as well as the ecological and functional diversity of soil microorganisms are significantly better than that of single fertilizer or non-uniform fertilizer application;From different dosages of fertilizer(fuquan positioning test):Although the 50%increase treatment of base fertilizer is much superiorer than other treatments in terms of agronomic traits,but it does not show absolute superiority in terms of economic benefits,tobacco leaf quality,tobacco leaf evaluation,microbial community,and enzyme activity.Therefore,in conclusion,the conventional fertilization is the best for field production.