EFFECT OF ANNUAL/BLENDED ALKALI/CANAL WATER IRRIGATION ON SESBANIA (GREEN MANURE)-POTATO-SUNFLOWER CROP ROTATION IN SEMI ARID REGIONS

Experiment on cyclic/conjunctive use of alkali/canal water in sesbania-potato-sunflower crop rotation was carried out at R.B.S. College, Bichpuri farm, Agra. Sesbania (Sesbania sesban) green manure, potato (Solanum tuberosum) and sunflower (Helianthus annus) were grown with combined use of good quality canal water (EC 1.1 dS/m, SAR 1.8) and alkali water (RSC 15.8 meq/l, EC 3.6 dS/m, SAR 1.4) for three years (2006-09) on a well drained sandy loam soil having ECe 2.5 dS/m, pH 7.9 and ESP 5.3). Increase in soil pH (8.9 to 9.2), soil salinity (4.7 to 5.2 dS/m) and soil sodicity (ESP 25 to 41) was observed under irrigation with alkali water which results in adverse effect on growth and yield of all crops. Average of 3 years data showed that the relative yields under cyclic use as compared to canal water ranged between 45-76% in potato and 58-72% in sunflower. Similarly, the average yield of potato and sunflower was 83% and 77% respectively under blended (2 canal and 1 sodic water) water irrigation. Considerable deterioration in quality of produce was observed in potato and weight loss on storage and smaller size of seeds and lower oil content in case of sunflower. The overall deterioration in soil properties under different modes was related to the proportions of alkali water applied.