Water-harvesting on arid coal mine soil for vegetable and fruit production

Abstract

The Black Mesa Water-Harvesting Agrisystem is testing the feasibility of using water-harvesting techniques to reclaim strip mined land. Two different treatments, fiberglass-asphalt-chipcoat and salt, were applied to increase the runoff from the catchment areas. The water is stored in ponds to provide ample irrigation to a variety of vegetables and fruits. This system would generate an estimated net annual revenue of $1400 per irrigated acre or approximately $348 per acre for the whole system. This income is a great improvement over the estimate of no net income from the conventional reclamation alternative of establishing forage. The potential high quality of Black Mesa spoil as agricultural soil is indicated by its loam texture, neutral pH, and high nitrogen level. After three years of fertilization with phosphate, irrigation, cropping and cultivation, the spoil is developing a friable, granular structure. Some of the problems encountered in operating the system are: land subsidence on the regraded spoil, crop pests, and weed growth on the catchments. Nevertheless, it appears that the establishment of water-harvesting instead of, or in conjunction with, grazing would increase the future benefits from the land without increasing the costs of reclamation.