Zhang Yuting, He Xinhua, Liang Hong, Zhao Jian, Zhang Yueqiang, Xu Chen, Shi Xiaojun
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.
Environ Sci Pollut Res Int. 2016 Mar;23(6):5442-50. doi: 10.1007/s11356-015-5673-2. Epub 2015 Nov 14.
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.
相对于土壤酸化而言，土壤交换性阳离子的变化研究较少，特别是在长期经济作物种植的情况下。本研究调查了经过10年（2002 - 2012年）长期连续烟草种植后，阿利-周界性粘壤土的土壤酸化情况。2002年和2012年分别在中国西南部重庆市的七个烟草种植县的1933个和2143个地点（以及647株烟草植株）采集土壤样本。经过10年的连续烟草种植，土壤明显酸化，土壤pH平均下降0.20个单位，土壤向酸性状态转变的位点大幅增加，尤其是pH值在4.5至5.5之间的位点，而1.93 kmol H⁺ ha⁻¹ year⁻¹的产生主要源于氮肥输入和植物氮素吸收输出。10年后，所有七个烟草种植县的总交换性碱阳离子平均下降了27.6%，或pH值下降了0.20个单位。同时，pH每下降一个单位，2002年和2012年分别消耗40.3和28.3 mmol碱阳离子 kg⁻¹土壤。此外，地上烟草生物量收获每年从土壤中带走339.23 kg碱阳离子 ha⁻¹，这比阴离子带走量高7.57倍，导致每年12.52 kmol H⁺ ha⁻¹的产生，这是导致土壤酸化的主要原因。总体而言，我们的结果表明，长期烟草种植不仅加剧了土壤酸化，还降低了土壤的酸缓冲能力，对土壤可持续利用产生负面影响。另一方面，我们的结果强调了持续监测烟草种植地土壤pH变化的重要性，这将增进我们对该地区土壤健康肥力的理解。
