title: Long-term tobacco plantation induces soil acidification and soil base cation loss.
abstract: Changes in soil exchangeable cations relative to soil acidification are less studied particularly under long-term cash crop plantation. This study investigated soil acidification in an Ali-Periudic Argosols after 10-year (2002-2012) long-term continuous tobacco plantation. Soils were respectively sampled at 1933 and 2143 sites in 2002 and 2012 (also 647 tobacco plants), from seven tobacco plantation counties in the Chongqing Municipal City, southwest China. After 10-year continuous tobacco plantation, a substantial acidification was evidenced by an average decrease of 0.20 soil pH unit with a substantial increase of soil sites toward the acidic status, especially those pH ranging from 4.5 to 5.5, whereas 1.93 kmol H(+) production ha(-1) year(-1) was mostly derived from nitrogen (N) fertilizer input and plant N uptake output. After 1 decade, an average decrease of 27.6 % total exchangeable base cations or of 0.20 pH unit occurred in all seven tobacco plantation counties. Meanwhile, for one unit pH decrease, 40.3 and 28.3 mmol base cations kg(-1) soil were consumed in 2002 and 2012, respectively. Furthermore, the aboveground tobacco biomass harvest removed 339.23 kg base cations ha(-1) year(-1) from soil, which was 7.57 times higher than the anions removal, leading to a 12.52 kmol H(+) production ha(-1) year(-1) as the main reason inducing soil acidification. Overall, our results showed that long-term tobacco plantation not only stimulated soil acidification but also decreased soil acid-buffering capacity, resulting in negative effects on sustainable soil uses. On the other hand, our results addressed the importance of a continuous monitoring of soil pH changes in tobacco plantation sites, which would enhance our understanding of soil fertility of health in this region.
authors.affiliation: College of Resources and Environment, Southwest University, Chongqing, 400716, China.|National Monitoring Station of Soil Fertility and Fertilizer Efficiency on Purple Soils, Chongqing, 400716, China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Centre of Excellence for Soil Biology, College of Resources and Environment, Southwest University, Chongqing, 400716, China.|Department of Environmental Sciences, University of Sydney, Eveleigh, NSW 2015, Australia.
authors.forename: Xinhua
authors.initials: X
authors.lastname: He
authors.affiliation: College of Agriculture, Guizhou University, Guiyang, 550025, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liang
authors.affiliation: Technology Research Centre, Zunyi Tobacco Company, Zunyi, 563000, Guizhou, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.affiliation: College of Resources and Environment, Southwest University, Chongqing, 400716, China.|National Monitoring Station of Soil Fertility and Fertilizer Efficiency on Purple Soils, Chongqing, 400716, China.
authors.forename: Yueqiang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Tobacco Scientific Research Institute, Chongqing Tobacco Company, Chongqing, 400716, China. xuchen@cq.tobaccco.cn.
authors.forename: Chen
authors.initials: C
authors.lastname: Xu
authors.affiliation: College of Resources and Environment, Southwest University, Chongqing, 400716, China. shixj@swu.edu.cn.|National Monitoring Station of Soil Fertility and Fertilizer Efficiency on Purple Soils, Chongqing, 400716, China. shixj@swu.edu.cn.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Shi
mesh_terms: D018533:Biomass; D002412:Cations / Q000032:analysis; D002681:China; D005308:Fertilizers / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D014026:Nicotiana / Q000737:chemistry / Q000254:growth & development*
chemical_list: D002412:Cations; D005308:Fertilizers; D012987:Soil; D009584:Nitrogen
keywords: Acid-buffering capacity; Ali-Periudic Argosols; Exchangeable base cations; H+ budget; Nicotiana tabacum; Soil pH