Pilot-scale demonstration study of the impact of fly ash on soil fertility and crop yield

摘要

Pilot-scale demonstrations of the use of fly ash as a soil modifier and supplier of micronutrients to improve agricultural productivity, based on a process optimized at lab scale at the Regional Research Laboratory, Bhopal, India, were conducted. The field-demonstration trials were carried out in Uttar Pradesh (northern India), Orissa (south-eastern India), and Madhya Pradesh (central India), under different soil conditions for various crops. Some 100-650 tonnes of fly ash per hectare were applied, depending upon the soil and fly-ash characteristics. Both short- and long-term studies of the impact of fly ash on soil and food quality were conducted. With fly-ash application, the edible yields of tomato, cabbage, potato, wheat, pea, onion, rice, sunflower, maize, etc. increased from 12 to 46%, compared to the control soil where no fly ash was used. The crop responses to various elements, mainly heavy metals in soil and fly-ash-admixed soil, were found to be comparable to that of the control, within permissible limits, and to meet food quality standards. The results of the impact of fly ash on the biotic and abiotic properties of soil, along with the quantity and quality of agricultural produce grown in pilot-scale demonstrations in three different parts of India, are discussed in this paper. The outcome of this work could act as a guide to build confidence and to maximize the use of fly ash, generated from thermal power plants worldwide, as one of the major mineral wastes utilized for agriculture purposes.