Integrating Cover Crops for Nitrogen Management in Corn Systems on Northeastern U.S. Dairies

Abstract

Northeastern U.S. (New York, Pennsylvania, and New England states) dairy farmers are increasingly interested in improving soil health, nutrient sequestration, and dry matter production. Consequently, farmers ask about managing winter cover crops (WCCs) in corn silage (Zea mays L.) rotations. In this literature review we identify WCCs most suitable to the Northeast, and summarize studies on (i) fall and spring N accumulation, (ii) nitrogen fertilizer replacement value (NFRV) for the next corn crop, and (3) environmental and management variables that aff ect N uptake and NFRV. We also discuss the literature on use of WCCs as forage commodity crops. Overwintering species most suitable for corn silage rotations are wheat (Triticum aestivum L.), cereal rye (Secale cereale L.) and triticale (X Triticosecale Wittm.). Clover (Trifolium spp.) and vetch (Vicia spp.) can add N but require inter-seeding in the Northeast. Th e NFRV for vetch typically exceeds that of clover, while the NFRVs of winter cereals tend to be low or negative. A few studies suggest cover crop termination with herbicides compared to tillage incorporation can, when no fertilizer N or manure is added, result in slower decomposition and more gradual N release. Research on the eff ects of tillage on NFRVs of cover crops is inconclusive. When seeded aft er corn silage, cereal rye is most eff ective in N uptake in fall and spring. A corn rotation that includes cereal rye or triticale that can be harvested has the potential to reduce soil erosion, capture residual N, increase annual forage yields, and provide quality forage.

Planting Green Effects on Corn and Soybean Production

“…Greater CC biomass has also been shown to improve some soil health parameters such as bulk density (Duiker and Curran, 2005), water holding capacity (Basche et al, 2016), infiltration (Blanco-Canqui et al, 2015), and soil C (Karlen et al, 1994). Further, more biomass and residue cover can improve weed suppression (Mischler et al, 2010;Finney et al, 2016), reduce nutrient leaching from the system (Alonso-Ayuso et al, 2014;Farsad et al, 2011;Finney et al, 2016), and extend the time for N 2 fixation by leguminous CCs (Cook et al, 2010;Wagger, 1989;Ketterings et al, 2015). More CC biomass may also provide habitat for beneficial arthropods (Finke and Denno, 2002) including slug predators, potentially providing slug predator suppression, while the living CC may provide alternative food for slugs, further reducing slug damage of main crops (Brooks et al, 2005;Le Gall and Tooker, 2017).…”

Double‐Cropping with Forage Sorghum and Forage Triticale in New York

“…During the corn silage years, the soil is often left bare over the winter months due to relatively short growing seasons in this region. However, planting cover crops following corn silage harvest has become a more common practice in recent years, reducing the risk of soil erosion associated with bare soil, as well as aiding in nutrient recycling and soil fertility management (Long et al, 2013; Ketterings et al, 2015b; Lyons et al, 2017). Harvesting winter‐hardy cover crops for forage in the spring, defined here as double‐cropping, can provide an additional benefit of spring yield (Ketterings et al, 2015a; Lyons et al, 2019c).…”

Green and animal manure use in organic field crop systems

“…Legume crops producing >4,000 kg ha −1 of aboveground DM provided large amounts of PAN to subsequent grain crops (Parr, Grossman, Reberg‐Horton, Brinton, & Crozier, 2011; Teasdale, Devine, Mosjidis, Bellinder, & Beste, 2004). Hairy vetch produced up to 150 kg N ha −1 in southern portions of Humid Coastal North America (Figure 1), and up to 52 kg N ha −1 further north (Decker, Clark, Meisinger, Mulford, & McIntosh, 1994; Dou, Fox, & Toth, 1994; Ketterings et al., 2015; Sarrantonio & Scott, 1988; Teasdale et al., 2004, 2012). However, optimal growth of legume crops (i.e., early seeding and late termination) is not always feasible because of crop rotation considerations and other management constraints (Ketterings et al., 2015; Mirsky et al., 2017; Buckland, Reeve, Creech, & Durham, 2018).…”

“…Hairy vetch produced up to 150 kg N ha −1 in southern portions of Humid Coastal North America (Figure 1), and up to 52 kg N ha −1 further north (Decker, Clark, Meisinger, Mulford, & McIntosh, 1994; Dou, Fox, & Toth, 1994; Ketterings et al., 2015; Sarrantonio & Scott, 1988; Teasdale et al., 2004, 2012). However, optimal growth of legume crops (i.e., early seeding and late termination) is not always feasible because of crop rotation considerations and other management constraints (Ketterings et al., 2015; Mirsky et al., 2017; Buckland, Reeve, Creech, & Durham, 2018). Hairy vetch produced <4,000 kg ha −1 in some environments in eastern North America (Reberg‐Horton et al., 2012; Teasdale & Mohler, 2000; Yenish, Worsham, & York, 1996), and DM yields exceeded 4,000 kg ha −1 in only one of four years in the semi‐arid Great Plains (Carr, Gramig, & Hogstad, 2016).…”