Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2006
Publication Date: 6/5/2006
Citation: Blaser, B.C., Gibson, L.R., Singer, J.W., Jannink, J.L. 2006. Optimizing seeding rates for winter cereal grains and frost-seeded red clover intercrops. Agronomy Journal. 98(4):1041-1049.
Interpretive Summary: Intercropping red clover with winter cereal grains could provide a forage and nitrogen source for corn. Few studies have evaluated the productivity and management of winter cereal grain/legume intercrops. This study was conducted from 2002 through 2004 to determine optimum seeding rates for maximizing cereal grain and red clover forage yields. The current winter cereal grain seeding rate of 1,200,000 seeds/acre maximized grain yield with acceptable red clover establishment. Red clover forage yield was maximized at seeding rates between 15 and 20 lb seed/acre. These results are important to winter cereal grain and forage producers because seeding rates for maximum grain and forage productivity were quantified.
Technical Abstract: Growing winter cereal grain/forage legume intercrops could provide multiple benefits to cropping systems in the North Central U.S. Intercropping red clover (Trifolium pratense L.) with winter cereal grains could provide forage and a green manure crop. There have been few studies evaluating the productivity and management of winter cereal grain/legume intercrops. This study was conducted in the 2002-03 and 2003-04 growing seasons to determine optimum seeding rates for maximizing cereal grain and red clover forage yields. In March, red clover was frost-seeded at 0, 300, 600, 900, 1200, and 1500 seeds m-2 into winter wheat (Triticum aestivum L.) and triticale (X Triticosecale Wittmack) seeded at 100, 200, 300, and 400 seeds m-2 the previous October. When examined across cereal grain species and year, 300 seeds m-2 cereal grain seeding rate was optimum for grain yield (4.13 and 3.53 Mg ha-1 in 2003 and 2004, respectively) and acceptable for red clover establishment. Red clover plant densities after cereal grain harvest were 10 to 22% of the seeding rates. Red clover dry matter (DM) production was maximized at 3.49 Mg ha-1 with 900 seeds m-2 in 2003 and 6.67 Mg ha-1 with 1200 seeds m-2 in 2004. The results suggested a winter cereal grain/red clover intercrop could be successfully established in the North Central U.S. using a winter cereal grain seeding rate of 300 seeds m-2 and red clover seeding rates between 900 to 1200 seeds m-2.