Establishment and Impact of Cover Crops Intersown into Corn

Abstract

In temperate climates, corn (Zea mays L.) is often harvested too late for sufficient cover crop growth to meet grower objectives. This study was conducted to evaluate intersowing into standing corn in terms of cover crop establishment and growth and the impact on corn yield. Three experiments were conducted from 2009 to 2011 in southwestern Ontario sweet and hybrid seed corn production systems to assess timing of cover crop intersowing, utility of alfalfa (Medicago sativa L.) and 17 other cover crops species or multispecies mixes. In all 22 locations over 3 yr, corn yield was not affected in any of the three cover crop experiments. Sweet corn cover crop treatments exhibited poor stands of limited growth (<1% ground coverage) at corn harvest, attributed to sweet corn canopy closure. At seed corn harvest, early‐sown (corn V4–V6) cover crops accumulated 1116 kg ha−1 dry biomass and 42.4 kg N ha−1, which were 33% greater than the late‐sown (V10–V12) treatments. A lack of a cover crop effect compared with the no‐cover‐crop treatment in soil mineral N and corn yield indicates little N competition. Hairy vetch (Vicia villosa Roth), oilseed radish (OSR, Raphanus sativus L. var. oleoferus Stokes) and three of six cover crop blends were the only treatments to accumulate dry biomass over 1000 kg ha−1 by corn harvest. Of the cover crops evaluated, interseeding into hybrid seed corn production systems appears to be of little risk to yield and can provide ground cover during postharvest fallow periods.

Evaluation of cover crops drill‐interseeded into corn across the Mid‐Atlantic

“…These results are supported by previous research that suggests either densely planted corn (>30,000 plants/ac) or crops that fully canopy, such as soybean, may be too competitive for interseeded cover crops (Baributsa et al, 2008; Belfry and Van Eerd, 2016; Stute and Posner, 1993). In our previous interseeder research, several field trials failed when interseeded cover crop species established but failed to survive the corn growing season due to the combination of corn interference and additional environmental stress such as periods of drought.…”

“…Broadcast interseeding cover crops into cash crops earlier in the growing season was a common and recommended practice in the 1940s (Dickey, 1947); research investigating various interseeding strategies has been conducted periodically over the last several decades (Abdin et al, 1998; Belfry and Van Eerd, 2016; Scott et al, 1987; Triplett, 1962). For example, cover crop interseeding is more common in low‐input or organic annual grain production systems as a method to build soil health and provide N to the following cash crop (Baributsa et al, 2008; Exner and Cruse, 1993).…”

Establishment and Function of Cover Crops Interseeded into Corn

“…Cover crop N content in the fall was not affected by location, cover crop species, or planting method (Table 2), and average N content ranged from only 0.3 to 2.6 kg N ha −1 , compared with reports of 0.1 to 45 (Wilson et al, 2013) and 15 to 57 kg N ha −1 (Belfry and Van Eerd, 2016). The importance of fall N uptake may vary depending on levels of residual soil N after the corn crop, but cover crop benefit will most frequently be associated with successful establishment, winter survival, and spring N uptake, since the greatest risk of N loss occurs in the spring (Randall et al, 2003).…”

Interseeding cover crops in corn

“…Researchers have examined interseeding several cover crop species including annual ryegrass ( Lolium multiflorum Lam.) and crimson clover seeded as a single species and in mixtures (Abdin et al., , ; Belfry & Van Eerd, ; Caswell, Wallace, Curran, Mirsky, & Ryan, ; Curran et al., ; Grabber, Jokela, & Lauer, ; Scott, Mt. Pleasant, Burt, & Otis, ; Youngerman, DiTommaso, Curran, Mirsky, & Ryan, ; Zhou, Madramootoo, MacKenzie, Kaluli, & Smith, ), and oilseed radish ( Raphanus sativus L.) interseeded as a single species in Pennsylvania and Ontario, Canada (Belfry & Van Eerd, ; Roth, Curran, Wallace, Ryan, & Mirsky, ) and in a mixture in Minnesota (Noland et al., )…”

“…and crimson clover seeded as a single species and in mixtures (Abdin et al, 1997(Abdin et al, , 1998Belfry & Van Eerd, 2016;Caswell, Wallace, Curran, Mirsky, & Ryan, 2019;Curran et al, 2018;Grabber, Jokela, & Lauer, 2014;Scott, Mt. Pleasant, Burt, & Otis, 1987;Youngerman, DiTommaso, Curran, Mirsky, & Ryan, 2018;Zhou, Madramootoo, MacKenzie, Kaluli, & Smith, 2000), and oilseed radish (Raphanus sativus L.) interseeded as a single species in Pennsylvania and Ontario, Canada (Belfry & Van Eerd, 2016;Roth, Curran, Wallace, Ryan, & Mirsky, 2015) and in a mixture in Minnesota (Noland et al, 2018) A major concern with interseeding is whether cover crops will act as weeds and compete with corn (Hall, Swanton, & Anderson, 1992). The competitiveness of weeds in corn depends on the time the weeds emerge in relation to corn emergence, weed species, and weed density.…”