Effects of Continuous Cropping on Soil Microbial Biomas s of Tobacco Field and Quality of Flue-cured Tobacco
The soil microbial quantity and quality of flue-cured tobacco were studied in tobacco field , in which crop rotation , 3-year continuous cropping , and 6-year continuous cropping had been carried out .The results showed that:from resettling stage to vigorous growth stage , further to mature period , the bacterial population in the soil reduced gradually , and it was the highest in the soil of crop rotation .The fungal number in the soil of crop rotation was less than that in the soil of continuous cropping , it reached the maximum at resettling stage in the soil of 6-year continuous cropping , and was significantly higher than that in the soil of crop rotation and 3-year continuous cropping .As for the number of actinomyces in the soil , the following order was found:crop rotation>continuous cropping for 3 years>continuous cropping for 6 years; at resettling stage>at vigorous growth stage>in mature period . There were significant differences in some physical characteristics of flue-cured tobacco ( such as filling value , leaf thickness , ten-sion stress, specific weight of leaf and stem ratio ) between crop rotation and 3-year continuous cropping , but the other indexes had no significant difference .As for the chemical properties of flue-cured tobacco , sugar-nicotine ratio , nitrogen-nicotine ratio , ratio of potassium to chlorine , and Schmuck value showed the sequence of crop rotation >continuous cropping for 6 years>continuous crop-ping for 3 years, they were all in the appropriate range , and their coordination in crop rotation treatment was better than that in con-tinuous cropping treatment .The total amount of neutral aroma components ( excluding neophytadiene ) showed crop rotation >contin-uous cropping for 6 years >continuous cropping for 3 years.
国家科技期刊平台
NSTL
万方数据
维普
