ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India; Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdom.
ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
Sci Total Environ. 2017 Apr 1;583:344-351. doi: 10.1016/j.scitotenv.2017.01.074. Epub 2017 Jan 20.
Overburden and acid drainage from coal mining is transforming productive agricultural lands to unproductive wasteland in some parts of Northeast India. We have investigated the adverse effects of acid mine drainage on the soil of rice paddy and productivity by comparing them with non-mined land and abandoned paddy fields of Jaintia Hills in Northeast India. Pot experiments with a local rice cultivar (Myngoi) as test crop evaluated biological productivity of the contaminated soil. Contamination from overburden and acid mine drainage acidified the soil by 0.5 pH units, increased the exchangeable Al content 2-fold and its saturation on clay complexes by 53%. Available sulfur and extractable heavy metals, namely Fe, Mn and Cu increased several-fold in excess of critical limits, while the availability of phosphorus, potassium and zinc contents diminished by 32-62%. The grain yield of rice was 62% less from fields contaminated with acid mine drainage than from fields that have not suffered. Similarly, the amounts of vegetation, i.e. shoots and roots, in pots filled with soil from fields that received acid mine drainage were 59-68% less than from uncontaminated land (average shoot weight: 7.9±2.12gpot; average root weight: 3.40±1.15gpot). Paddy fields recovered some of their productivity 4years after mining ceased. Step-wise multiple regression analysis affirmed that shoot weight in the pots and grain yield in field were significantly (p<0.01) and positively influenced by the soil's pH and its contents of K, N and Zn, while concentration of S in excess of threshold limits in contaminated soil significantly (p<0.01) reduced the weight of shoots in the pots and grain yield in the field.
在印度东北部的一些地区，采煤造成的负担过重和酸性排水使原本肥沃的农田变成了不毛之地。我们通过比较印度东北部贾因提亚丘陵地区未开采土地和废弃稻田，研究了酸性矿山排水对稻田土壤和生产力的不利影响。采用当地水稻品种（Myngoi）作为供试作物的盆栽试验评估了受污染土壤的生物生产力。覆盖层和酸性矿山排水造成的污染使土壤酸化了 0.5 个 pH 单位，将交换性 Al 含量增加了两倍，将其在粘土络合物中的饱和度增加了 53%。土壤中有效硫和可提取重金属（Fe、Mn 和 Cu）的含量增加了数倍，超过了临界极限，而磷、钾和锌的含量则减少了 32-62%。受酸性矿山排水污染的稻田的稻谷产量比未受污染的稻田低 62%。同样，用受酸性矿山排水污染的田地土壤填充的花盆中植被（即茎叶和根系）的数量比未受污染的土地少 59-68%（平均茎叶重量：7.9±2.12g 盆；平均根重：3.40±1.15g 盆）。在停止采矿 4 年后，稻田的部分生产力得到了恢复。逐步多元回归分析证实，盆栽中茎叶的重量和田间的稻谷产量与土壤的 pH 值及其 K、N 和 Zn 含量呈显著正相关（p<0.01），而受污染土壤中超过阈值的 S 浓度显著降低了盆栽中茎叶的重量和田间的稻谷产量（p<0.01）。
