Management of self-seeding winter cereal cover crops in a soybean-corn rotation

Abstract

Cover crops provide environmental benefits, yet adoption in agronomic farming systems is low. Winter rye (Secale cereale L.), wheat (Triticum aestivum L.), and triticale (x Triticosecale Wittmack) were used to develop self-seeding cover crop systems in a soybean [Glycine max (L.) Merr.]-corn (Zea mays L.) rotation. Winter cereals were seeded in two or four 19-cm rows between each future 76-cm soybean row. Management systems in soybean were four rows with early (4REB) and late (4RLB) spring glyphosate to eliminate two rows adjacent to the soybean row and mechanical control, four rows with mechanical control (4RNB) only, two rows with mechanical control (2RB), and two rows with no mechanical control (2RBNC). These residual treatments were managed in corn the following year to promote self-seeding using chemical and mechanical control. In both corn years, treatment 2RBNC in rye increased in plant density until late October, while wheat and triticale treatments were at final plant densities following soybean harvest in 2004. In 2005, wheat plant density increased until one week after soybean harvest. The winter cereal cover crops self-seeded enough to produce green ground cover of 29% in treatment 2RBNC in the late fall of 2004, while all other treatments had 15% green ground cover. Wheat treatments in late fall of 2005 had between 36 and 61% green ground cover, which could reduce erosion significantly. The cover crop self-seeded adequately after soybean, but after two years few