SALINITY TOLERANCE AND MANAGEMENT FOR ALFALFA

Vegetative forage production is basically a linear function of plant transpiration. Open stomata with lots of water vapor leaving the plant (transpiration) allows for maximum carbon dioxide up-take to build plant carbohydrates and biomass. Excessive salinity in the crop rootzone creates osmotic stress that reduces root uptake of water and crop transpiration. The added stress then reduces forage yield. At the same time, Class 1 water and land costs have doubled in the last 3 to 4 years; forcing hay growers to more marginal ground. This paper discusses current published salinity tolerance levels for alfalfa, some practical observations from the field and strategies to reclaim salty ground