Growth of Three Forage Species in Saline Conditions

Abstract

Extensive areas of salt deposits are rendering agricultural soils in arid regions unsuitable for arable cropping. Identifying native plant species to grow in salt-affected soils or to grow with saline water may sustain productivity of salt affected lands. The objective of this greenhouse study was to compare biomass production and ion accumulation (i.e., Ca 2+ , Mg 2+ , Na + , and Cl m ) in potential salt tolerant forage species grown under simulated saline conditions found near La Junta region in southeast Colorado, USA. Seed-derived plants of tall fescue (Festucaarundinacea), narrowleafed birdsfoot trefoil (Lotus glaber), and broadleafed birdsfoot trefoil (Lotus corniculatus) were grown in pots filled with soil collected from nonsaline and saline areas near La Junta. Pots were irrigated with one of three qualities of water differing in EC: 0.13, 0.27, and 0.64 S m m 1 . For all treatments, F.arundinacea produced almost twice as much dry matter (DM) as L. glaber and L.corniculatus. Soil/water quality treatments appeared to have minimal effect on the DM yield of all species in 319 d, although DM yield appeared to be stimulated in L. glaber by either saline water or when grown in saline soil. Herbage Ca 2+ concentrations in all plants were higher when grown in nonsaline soil and decreased as water quality decreased. Herbage Mg 2+ concentrations were not affected by soil or water quality treatments. In contrast, herbage Na + and Cl m concentrations increased in all three species grown in either saline soils or irrigated with saline water. Soil EC increased at harvest for all plant species irrigated with saline water in both saline and nonsaline soils. Based on the growth responses observed for the three forage species under saline conditions, they all appear to be capable of growing in the salt-affected conditions of the La Junta region. Salt management practices will eventually be necessary to sustain productivity.