title: Acid drainage from coal mining: Effect on paddy soil and productivity of rice.
abstract: 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 Al3+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-1; average root weight: 3.40±1.15gpot-1). 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.
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India; Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdom. Electronic address: burhan3i@yahoo.com.
authors.forename: Burhan U
authors.initials: BU
authors.lastname: Choudhury
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Akbar
authors.initials: A
authors.lastname: Malang
authors.affiliation: Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Webster
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Kamal P
authors.initials: KP
authors.lastname: Mohapatra
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Bibhash C
authors.initials: BC
authors.lastname: Verma
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Anup
authors.initials: A
authors.lastname: Das
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Mokidul
authors.initials: M
authors.lastname: Islam
authors.affiliation: ICAR Research Complex for North Eastern Hill Region, Umiam, Meghalaya 793 103, India.
authors.forename: Samarendra
authors.initials: S
authors.lastname: Hazarika
mesh_terms: D000383:Agriculture / Q000706:statistics & numerical data*; D003032:Coal Mining; D004784:Environmental Monitoring; D007194:India; D019216:Metals, Heavy / Q000032:analysis*; D012275:Oryza; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants
keywords: Acid mine drainage; Agriculture; Overburden; Paddy soil; Rice productivity