Sodic Soil Reclamation in a Semi-Arid Region Involving Organic Amendments and Vegetative Remediation by Casuarina equsetifolia and Erianthus arundinaceus

Abstract

In arid and semi-arid regions of the world, certain farming practices and land management have resulted in saline/sodic soils. An experimental study was carried out in a semi-arid region of Southern India, where excess irrigation in the uplands has caused sodic soils in low-lying areas. In order to alleviate the sodicity problem, a combined approach involving application of organic manure, green manuring with Sesbania rostrata and subsequently vegetative remediation by plantation of Casuarina equsetifolia and Erianthus arundinaceus clones was attempted. The use of Erianthus arundinaceus in the integrated treatment along with other amendments is first of its kind in the region and about 20 % of reduction in Exchangeable Sodium Percentage (ESP) was achieved over the initial values. The initial values of ESP in the control plot as wells as treated plot at three different depths varied between 44 and 42.3 %, and after treatment with organic amendments followed by Casuarina and Erianthus plantations, the ESP was reduced to 35–36.5 %. Vegetative remediation in combination with other amendments considerably improved the major and micro nutrients besides nurturing the soil micro-organisms and enzyme activity. At the end of the experiment, about 81 % - 92 % survival rate of the crops was obtained. The cost-benefit ratio analysis based on the market demand for pulpwood ranged between 1:1.75 and 1:2.05. Overall, the experimental results ascertained that the integrated approach for reclamation of sodic soil has been found to be an efficient, cost effective and environmentally sound strategy for semi-arid regions.