Prolonged liberal irrigation of agricultural fields is likely to...

Prolonged liberal irrigation of agricultural fields create the problem of salinity. Since, all surface ground water contains salts to varying degrees, irrigation is the primary cause which brings salinity to the field. Related Theory Salinity and alkalinity problems are most likely to occur under 2 conditions: (i) Intrusion of salt water into low-lying areas near oceans and seas. (ii) Irrigated soils in semi-arid and arid regions (less than $500 \mathrm{~mm}$ annual rainfall) where rainfall or irrigation isn't sufficient to leach accumulated salts out of the root zone. The salts are released by decomposing rock and other parent material below the subsoil and are also brought in by irrigation water and additions of chemical fertilizers and manure.