Can livestock producers manage snow to grow more alfalfa in dryland watersheds?

Double rows of tall wheatgrass (ThinoDvrum Donticum), spaced on 15.2-m centers, have been recommended as vegetative windbreaks designed to enhance snowcovers and moderate growing-season evapotranspiration on the northern Great Plains and the Canadian Prairies. Such a windbreak system along with an adjacent open area on non-irrigated land near Swift Current, Saskatchewan, was seeded to three alfalfa varieties (Rangelander, Beaver and Angus) in 1986. Snowcover water equivalents, spring soil water contents, alfalfa water consumption, and forage production in all three varieties, observed over seven years, were significantly greater in the windbreak shelter than in the open field. The over-winter recharge of water in the upper 120 cm of soil averaged 22 mm (78%) greater behind the windbreaks than in the open. This extra water contributed to a 40% increase in mean annual forage yield from 1610 to 2250 kg ha-l.