Abstract
A series of field experiments in the Fourth Drainage Project Area (Site 1 at Chak 140/RB., Site 2 at Chak 147/RB, Site 3 at Chak 123/G.B.), Faisalabad were carried out on saline-sodic soils (ECe 5.7-385 dS rn', pHs 807-852, SAR 366-145.0, and 9.0-35.2 dS rn', 810-8.52, 37.2-109.8 at 0-15 and 15-30 em soil depths, respectively) following ricewheat crop rotation using tube well water for irrigation (EC 2.2-43 dS m", SAR 78-28.0, RSC 04-146 mrnol, L\ The treatments employed were; T1) Tube well water alone, T2) Soil-applied gypsum @ 50 % gypsum requirement of soil (25 % SGR to each of the first two crops), T3) Soil-applied FYM @ 10 t acre' annually before rice, T4) Combination of treatments 2 and 3. Up-till-now, three crops of rice and two that of wheat have been harvested After rice harvest in Nov. 2003, soil ECe, SAR and pHs for both the soil depths at all the three sites decreased Overall percent decrease being maximum with T2 followed by T4, T3 and T1. There was considerable differences in the effectiveness of treatments to improve these saline-sodic soils at different sites indicating a site-specific approach, based on soil and irrigation water characterization for their amelioration. Since these soils were highly saline-sodic and lying barren for the last> 30 years, first crop of rice 2001 was poor but the yields of the following crops gradually improved. Overall, rice and wheat yields were the highest with T2 followed by T4, T3 and Tt. The cost of reclamation treatments was recovered from the first two crops at sites 2 and 3 but from three crops at site 1. Overall, the net benefit was maximum with T2 followed by T4, T3 and T1. Net income was the highest at site 2 followed by sites 3 and 1. The farmer's skill and management in agronomic operations during reclamation appeared a key factor to realize economic yields and soil amelioration. It is recommended that farmer education and supply of quality inputs in time and space must be insured and soil amelioration projects are worth investment under the existing agro-ecological and socio-economical conditions of Pakistan for food security, rural poverty alleviation and cleaning of the environment through the decreased effect of green house gases.
