EFFECT OF IRRIGATION WATER SALINITY ON TRANSPIRATION AND LEACHING REQUIREMENT: A CASE STUDY FOR WHEAT UNDER SEMIARID ENVIRONMENT OF PUNJAB
Zainab Noreen, Muhammad Mohsin Waqas, Syed Hamid Hussain Shah
Salt is a natural component of soil and water. Salinization can be produced by natural processes such as weathering or mineral phase out of an ocean. Also, it can be produced by artificial means such as irrigation. Land degradation by salinity, sodicity or combination of both is one of the major impediments to agricultural productivity throughout the world. Most salt-affected soils occur in arid and semi-arid climates. Around 800 million hectares (mha) of land (5-6% of world total land area) are salt affected. The problem of salt affected soils is not new, but its intensity has been increasing because of poor management practices and inappropriate amelioration procedures. Keeping in view the salinity problem in the soils of Pakistan, analysis was taken in order to compute the leaching requirements of the soil of lysimeter at field site of water management research center. Irrigation were applied on the basis of leaching requirement of the soil to leach down the salts. The canal water yield was high 4.99 tons/ha as compared to the tubewell water 4.33 tons/ha. The ANSWER model was used to compare the actual and modeled. The R2 value for canal water yield was high (0.892) as compared to tubewell water yield (0.862). The evapotranspiration measurements were also be taken from water balance equation and results were showed that the tubewell water ET was more as compared to canal water because more water was applied to leach down the salts, so more water was also evaporates as compared to the canal water. The leachate of tubewell water was more as compared to the canal water due to the reason that more salts were present in the tubewell water and applied more water to leach down the salts.
Irrigation Water Salinity, Transpiration, Leaching Requirement