Dinesh Chandra Joshi

Title : Sustainable management of sodic water irrigated arid soils: Issues and strategies

Abstract:

The farming system in arid region of Rajasthan (India, rainfall zone of 200- 250 mm) in mainly rainfed but in pockets brackish ground water occurs, which is commonly used for irrigation. Brackish water, characterized by  low calcium, magnesium and sulphate ions and high sodium, carbonate and bicarbonate ions and high residual sodium carbonate (RSC) create sodicity in soil. Internationally, water containing RSC more than 2 m moles L^-1  (Eaton, 1950; Wilcox et al. 1954) and in arid Rajasthan RSC more than 5 m moles L^-1  (Joshi and Dhir, 1989) has been considered unsafe for irrigation.   Irrigation with water of higher RSC (10- 20 m moles L^-1) and high sodium adsorption ratio (SAR 20-35) and moderate salinity (3.5- 4.6 dSm^-1 ) causes severe sodicity in soil resulting in development of alkalinity pH (9.2- 10.5) and  high exchangeable sodium percent (40-50) in soils.

Biography:

D C Joshi (b,1943) former Principal Scientist at CAZRI (ICAR) Jodhpur and presently consultant; significant research contribution in the field of soil resources and land degradation mapping using remote sensing and GIS technology; humus characterization, micronutrient adsorption and availability, potassium dynamic and rehabilition of sodic lands; evident by 281 publication including 117 research papers in peer reviewed journals, 9 books (Edited) and 5 bulletins, 53 book chapters and 42 technical reports, 53 presentations in seminar/ symposia and 15 Popular articles. The book "Soil Resource Atlas of Rajasthan" brought by me which provides complete information on the soils of the Rajasthan State. Recently published books (1) Thar Desert in Retrospect and Prospect; by R. P. Dhir, D.C. Joshi and S. Kathju; (2) Remote Sensing and GIS applications: An starter Guide; by D.C. Joshi.