Preirrigation of a Severelysaline Soil With Insitu Water to Establish Dryland Forages

Alfalfa serves as one of the most important forage crops in North America. It is also one of the recommendedremedial crops for dryland salinity control. But, because of its limited salt tolerance, alfalfa does not establish satisfactorilyin severely or moderately saline soils. Preirrigations with the insitu ground water located beneath a severelysaline sitewere applied to seedbeds located within the same saline site before seeding Beaver alfalfa (Medicago sativa L.) and aRSH wheatgrass hybrid (Elymus Hoffmannii K.B. Jensen and K.H. Asay). In a field study conducted in semiaridSaskatchewan, fall irrigations with 4.6 dS/m water from a shallow, onsite well fitted with a solarpowered pump precededspring seeding. Plant emergence, spacing, height, cover, and forage yield of alfalfa compared by analysisofcovariance withand without irrigation were significantly improved following preirrigation. Mean alfalfa emergence increased from 20% to79%. The preirrigation significantly improved wheatgrass height and forage yield, but only indicated a trend towardimprovement in plant emergence, spacing, and cover. The mean plant height in July increased from 90 to 159 mm for thewheatgrass and from 35 to 140 mm for the alfalfa. The quantities of water applied as part of the nonirrigation andpreirrigation treatments ranged from zero to 2530 mm. Based on linear regression of irrigated amounts, every 119.3 mm ofirrigated, insitu water up to 2530 mm increased alfalfa forge yield by 10 g/m 2.