Leaching Saline Soils through Rainfall

Frequency analysis of rainfall for evaluating rainwater management in saline soils in a part of Haryana has been attempted. It has been assessed that dependable excess water for leaching is only available in the three months viz, July to September. The maximum rainfall in a day indicates that 20 cm high bunds can be used to contain the total storms of one day duration. Dry spells which follow appear to reduce the leaching capability of natural rainfall in the region. In the first year, kharif (monsoon season) crop cannot be taken unless additional leaching water is available. The total monsoon precipitation of 2.33 years return period is only capable of removing 90% of the salts from 45 cm of the soil profile which means a 10 to 15 mmhoslcm level of salinity will remain in the profile even after this leaching. Absence of levelling and bunding, presence of high water-table and total rainfall appear to influence the leaching wh'ch can however, be enhanced by resorting to levelling and bunding. Runoff from the area can be reduced to minimum by suitably bunding the fields. The results indicate that depending upon the management practices 50–70% of rainfall can contribute towards leaching.