Soil Acidity Indices, Nutrient Availability and Plant Growth through Amelioration Practices in Adjacent Coal-mine Paddy Soil

Abstract

Potential adjacent coal mine paddy soils often endure low soil and plant productivity through unscientific mining activities causing acid mine drainage. But the extent of its effect to soil is not known, therefore the study was taken to characterize coal mine affected lowland fields on the basis of soil acidity, identify the best amelioration practices and evaluate the performance on rice productivity at farmers’ field level. An experiment with a completely randomised block design (5 replicates) was performed to determine the effects of poultry manure (PM), compost (C), lime (L), paper mill sludge (PMS) and microbial consortium (MC) with their suitable combination through pot experimentation at College of Post Graduate Studies followed by the preeminent selected practices at field trials at Khliehriat, Meghalaya. The factors used were PM and C (10 t ha-1), L as CaCO3, PMS (250 and 500 kg ha-1) and MC were incorporated at appropriate rates. On categorization, two locations were found to exhibit extremely pH acid soil (pH 4.51 ± 0.51) i.e. Moonlakhep (L1) and ultra pH soil (pH 3.14 ± 0.23) i.e. Ladrymbai (L2). Integration of practices showed significant increase in soil acidic indices such as soil pH by 6% to 23% and significant decrease in exchangeable acidity by 49% to 18% with T4 at both locations. Confined increases of soil organic carbon by 12% to 40% with enhanced available soil nutrients by 40% at high optimum rates were noticed. Yield attributes were significantly influenced by different treatments. Highest plant height (83.58 cm and 81.32 cm), grain yield (3436 kg ha-1 and 3120 kg ha-1) were recorded under the practices of T4. However, stover yield (7875 kgha-1) was noticed in T8 at L1 and at L2 maximum in T4 (7420 kgha-1). Soil acidic indices, nutrient and crop growth were influenced at high optimum rates of soil amendment and enhanced with PM amended soil.