Mechanically reclaiming abandoned saline soils in Pakistan

✍ Scribed by S. A. Prathapar; M. Aslam; M. A. Kahlown; Z. Iqbal; A. S. Qureshi

• Book ID: 102282397
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 90 KB
• Volume: 54
• Category: Article
• ISSN: 1531-0353
• DOI: 10.1002/ird.206

✦ Synopsis

In areas where a saline water table is hydraulically linked to evaporation or evapotranspiration, water from the water table moves to meet partial or total evaporative demand. While water is lost to the atmosphere as vapour, salts are left behind, salinising the soil. Increase in sodium concentration on surface soils destroys soil structure, reduces its infiltration capacity and prevents leaching. These soils can be reclaimed if leaching is facilitated during monsoon months and capillary upflow is prevented during the remaining months. This paper presents the results of a field trial conducted to test this hypothesis.

The study covered two monsoon seasons, i.e. monsoons 1998 and 1999 in the Pakistani Punjab. Four treatments (T1, T2, T3 and T4) were triplicated at random. T1 consisted of three cultivations before the monsoon, T2 contained three cultivations before the monsoon and a cultivation after every heavy rainfall (>30 mm day À1 ), T3 consisted of three cultivations before the monsoon and a cultivation after alternate heavy rainfall (>30 mm day À1 ), and T4 was controlled with no cultivation. Infiltration rates measured at the end of the study for T1, T2 and T3 were higher than the initial rate measured at the beginning of the study. T2 showed most improvement. As for T4, the final infiltration rate was less than the initial rate, indicating further deterioration. Electrical conductivity and sodium adsorption ratio (SAR) showed similar trends.