Effect of Planting Method and Seeding Rate on the Establishment of Alfalfa Under Dryland and Irrigation

Production of forage is one of South Dakota\u27s greatest agricultural assets. The South Dakota Crop and Livestock Reporting Service indicated that 2,456,000 acres of alfalfa were harvested for hay in South Dakota in 1971 with an average yield of 1.55 tons/acre. In the future, irrigation will increase forage production and add a new dimension to South Dakota\u27s agriculture. South Dakota ranked eighth among states in all cattle and calves on January 1, 1972. Full stands of alfalfa are essential for the production of high yields of quality forage for this growing livestock industry. Satisfactory establishment of alfalfa with a companion crop has been inconsistent, especially in years of limited moisture. Preplant herbicides show promise for establishing pure stands of alfalfa fox hay and silage. With this method, new seedlings do not have to compete for plant nutrients, moisture, and light. Dense stands of alfalfa provide good weed control and high production in subsequent years. More information is needed to provide recommendations on alfalfa establishment methods, varieties, and seeding rates for use under both dryland and irrigated conditions. The experiment was designed with four objectives: 1) to compare a companion crop with the use of a preplant herbicide to establish alfalfa stands, 2) to compare the difference in alfalfa stand establishment when a companion crop is harvested for forage with the results when the companion crop is harvested as grain, 3) to measure differences in vigor and stand establishment comparing three alfalfa varieties under dryland and irrigation, and 4) to evaluate seeding rates to determine the most economical seeding rate or rates for maximum production.