| In order to prove effects of different organic materials on soil and tobacco quality,the dynamic changes of physical,chemical and biological properties of soil and effects on tobacco enzyme activity and routine chemical components of flue-cured tobacco were researched under biochar,straw,biochar + straw with equal carbon input conditions during the growth period of flue-cured tobacco.In order to provide reference to develop soil and tobacco quality.The results are as follows:1.Compared with single application of chemical fertilizers,the content of alkali hydrolysable nitrogen was reduced respectively by 3.4%~15.6%,5.0%~14.9%,5.9%~15.4% after adding biochar,straw and biochar+straw.the content of available phosphorus and available potassium were increased significantly after adding organic materials,Compared with single application of chemical fertilizers,the content of available phosphorus and available potassium were increased respectively by-9.6%~122.7%,9.1%~33.9%,26.0%~92.9% and-5.4%~25.6%,11.9%~21.4%,15.9%~31.9%after adding biochar,straw and biochar+straw.Compared with single application of chemical fertilizers,soil organic carbon fractions had a certain degree of improvement after adding organic materials during the growth period of flue-cured tobacco,there was a difference in the increase of organic carbon components in different growth stages.Compared with single application of chemical fertilizers,after adding biochar,straw and biochar+straw,the content of total organic carbon was increased respectively by 34.0%~45.3%,22.5%~84.6% and 32.6%~92.3%;the content of easily oxidized organic carbon was increased respectively by 45.7%~132.7%,61.0%~159.8% and 49.8%~148.4%;the content of dissolved organic carbon was increased respectively by 20.0%~55.6%,42.8%~118.8% and 34.0%~181.3%;the content of microbial biomass carbon was increased respectively by 22.4%~65.4%,42.9%~84.6% and 52.3%~92.3%.Compared with single application of chemical fertilizers,after adding organic materials,the content of soil total nitrogen was decreased significantly during the earth growth period of flue-cured tobacco and was increased significantly during the later growth period;the content of soil nitrate nitrogen was increased significantly;the content of soil ammonium nitrogen was decreased significantly;the content of soil microbial biomass nitrogen was increased significantly after adding straw and straw+biochar,the content of soil microbial biomass nitrogen was decreased significantly during the earth growth period of flue-cured tobacco and was increased significantly during the later growth period.2.During the growth period of flue-cured tobacco,the overall change in PH is modest.Compared with single application of chemical fertilizers,soil PH was significantly depressed after adding straw,soil PH was significantly increased after adding biochar,there was no significant change in soil PH after adding straw and biochar.Soil bulk density was decreased significantly after adding organic materials.Compared with single application of chemical fertilizers,soil bulk density was reduced respectively by 23.0%,15.4% and 20.1% after adding biochar,straw and biochar+straw.Compared with single application of chemical fertilizers,the content of water-stable aggregates of<0.053 mm was reduced respectively by 24.6%,11.2% and 6.8% after adding biochar,straw and biochar+straw;average water stability pellet weight diameter was no significantly different between straw application treatment and single application of chemical fertilizers treatment,it was increased respectively by 40.5% and 14.3% after adding biochar and biochar+straw.3.Soil enzyme activity was increased significantly after adding organic materials.Compared with single application of chemical fertilizers,urease activity was increased respectively by5.7~36.4%,11.6~35.0%,21.9~64.0%;sucrase activity was increased respectively by 3.9~17.5%,0~11.3%,7.5~19.2%;polyphenol oxidase activity was increased respectively by 2.7~12.9%,14.8~22.0%,16.9~29.0%;Catalase activity reached its maximum value when flue-cured tobacco were transplanted for 70 days,it was increased respectively by 6.0%,4.9%,8.2%.The species diversity of soil bacteria were significantly increased at the genus level after adding organic materials,the species diversity of soil bacteria were added to the most after adding biochar and straw after 40 days of transplanting,the species diversity of soil bacteria were added to the most after adding biochar after 100 days of transplanting.The abilities of soil microbes using all carbon source were significantly increased after adding organic materials.The abilities of soil microbes using all carbon source were expressed as biochar + straw application treatment> straw application treatment> biochar application treatment> single application of chemical fertilizers treatment after40 days of transplanting,The abilities of soil microbes using all carbon source were expressed as biochar + straw application treatment> biochar application treatment> straw application treatment>single application of chemical fertilizers treatment after 100 days of transplanting.The abilities of soil microbes using carbon source of phenolic acids were least after 40 days of transplanting;the abilities of soil microbes using carbon source of carbohydrates and amino acids were strongest after100 days of transplanting.The functional diversity of soil microbial community was highest after40 and 100 days of transplanting.The results of principal component analysis showed that the carbon source metabolic capacity of soil microbial community was significantly different between organic materials application treatment and single application of chemical fertilizers treatment,the carbon source metabolic capacity of soil microbial community was litter significantly different between straw application treatment and biochar+straw application treatment after 40 days of transplanting,the carbon source metabolic capacity of soil microbial community was no significantly different between biochar application treatment and biochar+straw application treatment after 100 days of transplanting.4.Soil respiration rate was significantly increased after adding organic materials,the respiration rate of application straw treatment was the highest 4.88?mol·m-2·s-1 in the later growth period(100 days transplanting),which was 33.7% higher than that of single application of chemical fertilizers.5.The content of conventional chemical ingredients of flue-cured tobacco leaves were in the proper range after adding biochar+straw.Compared with single application of chemical fertilizers,the content of total nitrogen and nicotine of flue-cured tobacco leaves was significantly increased after adding biochar,the content of total sugar,reducing sugar and sugar to alkali ratio of flue-cured tobacco leaves were significantly increased after adding straw. |
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