@article{Jifeng:262814,
      recid = {262814},
      author = {CHEN Jifeng and SUN Hui and XIA Yang and CAI Kaixuan and  LIU Hongyuan and LI Yuanyuan and GUO Ruiliang and HOU Bei  and FENG Shuai and JIANG Xiaoxin},
      title = {Changes in Soil Enzyme Activity and Nutrient Content in  Different Years of Continuous Cropping Tobacco Fields},
      journal = {Asian Agricultural Research},
      address = {2017-05-20},
      number = {1812-2017-1896},
      year = {2017},
      abstract = {In order to find out changes in the main fertility  indicators of continuous cropping tobacco fields in Henan  Province with years of continuous cropping, 5 typical  tobacco fields (Jia County, Zhaoling District, Fangcheng  County, Xiangcheng County, and Song County) were studied.  Indicators in question included activity of main enzymes  (sucrase, urease, catalase, and acid phosphatase), pH  value, organic matters, total nitrogen, available  phosphorus and available potassium. Results indicate that  in most tobacco fields, the activity of sucrase and urease  increased in two years of continuous cropping, later, it  showed a declining trend with increase in years of  continuous cropping; in some fields, it directly declined  with increase in years of continuous cropping; the activity  of catalase increased in two years of continuous cropping,  later, it showed a declining trend with increase in years  of continuous cropping, and it became stable after three  years of continuous cropping; generally, the activity of  acid phosphatase declined with increase in the years of  continuous cropping within 3 years continuous cropping,  later, it became stable. Except Fangcheng County, the soil  pH value of other districts (counties) generally declined  with increase in years of continuous cropping, and it was  in the range of 5.6-6.8. With the increase in continuous  cropping, the soil organic matters (SOM) in tobacco fields  of Jia County and Song County declined, changes of SOM in  tobacco fields of Fangcheng County and Xiangcheng County  were not obvious, and SOM showed the trend of first decline  then rise in Zhaoling District. In most tobacco fields (Jia  County, Xiangcheng County, and Song County), the total  nitrogen showed a declining trend; in Zhaoling District, it  showed a trend of first decline then rise; in Fangcheng  County, it showed a rising trend. The available phosphorus  firstly slightly declined then rose in tobacco fields of  Zhaoling District and Song County; it showed a trend of  first rise then decline in Jia County; there were no  obvious changes in Fangcheng County and Xiangcheng County.  Changes in the available potassium were different in  tobacco fields. In sum, there are certain rules for changes  in soil enzyme activity and nutrient content in tobacco  fields in Henan Province, but changes are not completely  the same. It is concluded that the site conditions and  farming activities exert certain a certain influence on  soil enzyme activity, pH value, organic matters, and  nitrogen, phosphorus and potassium content. Therefore, to  solve obstacles in continuous cropping of tobacco fields,  different regions should take different measures. },
      url = {http://ageconsearch.umn.edu/record/262814},
      doi = {https://doi.org/10.22004/ag.econ.262814},
}