Options for management of saline groundwater in an irrigated farming system

Abstract

Groundwater pumping is used to control salinity problems in many irrigation regions of Australia. Options for managing the pumped groundwater are required to be consistent with achieving high farm production levels and minimising salt export from irrigation regions. In this study, pasture production and economic aspects of 6 options for managing pumped groundwater are compared. The 6 options include (i) complete farm reuse of pumped groundwater for irrigation; (ii) complete export to river system; (iii) complete disposal to evaporation basin; (iv) partial farm reuse with reduced salt export; (v) partial farm reuse with reduced disposal to evaporation basin; and (vi) partial farm reuse with disposal to a salt tolerant forage crop. The comparison between the 6 options is made for a hypothetical 100 ha dairy farm that has a perennial pasture based production system. Complete farm reuse was the most economic option in areas where groundwater salinity is low (<5 dS/m). Partial farm reuse with disposal of surplus groundwater to a salt tolerant forage species was the most economical option for managing higher salinity groundwater.