Impact of irrigation and soil compaction on salinization of soils in semiarid agricultural lands

The use of saline groundwater for irrigation can lead to significant salt accumulation in agricultural soils. This in turn can lead to a decrease in crop yields threatening food security. This study examines the impact of irrigation pattern and soil compaction on the salt dynamics in soils. Laboratory-scale column experiments were conducted for different irrigation patterns, water quality and soil compaction conditions. Two water qualities were applied: fresh (DI water) and saline (~3.4 mS/cm). The soil columns (having 60 cm height and 16 cm diameter) were packed with agricultural soil samples from a 10-year non-tilled profile of an apple farm located in the plain of Konya, Turkey. The experiments were numerically modelled with the Hydrus-1D computer program which can simulate water and solute movement in unsaturated soils. Results show that the fate and transport of salts in the topsoil is governed by capillary action, evaporation, sub-surface soil compaction and soil moisture retention characteristics. Overall, it is demonstrated that properly managed irrigation schemes and tillage practices can help alleviate the problem of soil salinization. Farmer strategies to minimize the significance of salinity of agricultural soils are discussed.

Acknowledgement: This work was supported by the Scientific and Technological Research Council of Turkey [Project number: TUBİTAK-118Y343].