Management of Salt-Affected Soils - Practices of Irrigation and On-farm Water Management - page 308

Fig. 8.4 Schematic of a
recharge well
are often better choice than surface storage. In areas having alluvial aquifers with
good transmissibility, hydraulic conductivity and specific yield, recharge tubewells
improve water quality and availability more quickly than gradual percolation from
percolation tank or check dams. Figure 8.4 illustrates the design of a recharge well.
It is similar in construction to a discharge well (well for pumping).
Harvesting Rainwater at Farm Pond or Canal
The rain water can be harvested at the excavated farm pond or canal to cultivate
dry-season crop, when the soil salinity is high and there is no source of fresh water.
Ali and Rahman ( 2008b ) found 20:1 ratio of land area to pond area is sufficient to
cultivate low-water demanding dryland crops (other than rice) in saline area.
8.6.2.4 Chemical Practices (Reclamation/Treatment of Saline Soil)
These include chemical amendment and mineral fertilization. Saline soils are dom-
inated by neutral soluble salts and at high salinities sodium chloride is most
often the dominant salt although calcium and magnesium are present in sufficient
amounts to meet the plant growth needs. Since sodium chloride is most often the
dominant soluble salt, the SAR of the soil solution of saline soils is also high.
Sometimes amendment (gypsum application) is necessary for the reclamation of