Cover Crops for Sweet Corn Production in a Short‐Season Environment

Abstract

Legume cover crops can supply all or most of the N required by a subsequent crop if legume biomass is of sufficient quantity and N mineralization is approximately synchronous with crop demand. Three 2‐yr crop rotation cycles were conducted on a Lamoine silt loam (fine, illitic, nonacid, frigid Aeric Epiaquept) soil in Maine to (i) evaluate biomass and N accumulation of alfalfa (Medicago sativa L.), winter rye (Secale cereale L.), and hairy vetch (Vicia villosa Roth subsp. villosa) plus winter rye cover crops; (ii) determine sweet corn (Zea mays L.) response to legume and fertilizer N sources in a barley (Hordeum vulgare L.)–sweet corn rotation; and (iii) assess the accuracy of the presidedress soil nitrate test (PSNT) and leaf chlorophyll N test (LCNT) for distinguishing N‐responsive and nonresponsive sweet corn. Both legumes accumulated more N than rye grown alone, although total biomass was similar. Sweet corn following rye always exhibited a linear response to N fertilizer (up to 156 kg N ha−1), but generally exhibited no response to added N following either alfalfa or hairy vetch plus winter rye (VR). Both PSNT and LCNT were 75% accurate in identifying plots responsive to additional fertilizer N. The legume cover crops grown were able to replace all or nearly all of the N fertilizer required by a subsequent sweet corn crop, with fertilizer replacement values (FRVs) of 58 to 156 kg N ha−1 in a short‐season environment. These cover crops are a viable alternative source of N, greatly reducing or eliminating the need for N fertilizer.

Nitrogen cycling, profit margins and sweet corn yield under fall cover crop systems

“…Adequate summer rainfall (Table 3) Higher plant available N during the sweet corn season at Ridgetown than Bothwell (Table 7) provides some explanation as to why cover crops affected sweet corn yield in the 0 kg N ha (1 but not the 140 kg N ha (1 treatment at Bothwell and why there was no cover crop effect with or without N fertilizer at Ridgetown. In general, the positive effect of N fertilizer on total and marketable yield at Bothwell, and in total yield at Ridgetown was consistent with other research (Burket et al 1997;Mullins et al 1999;Griffin et al 2000;Cline and Silvernail 2002;Teasdale et al 2008). Similar to our study, Mullins et al (1999), Burket et al (1997), and Griffin et al (2000) observed variable weather during their studies, including hot dry years.…”

“…In general, the positive effect of N fertilizer on total and marketable yield at Bothwell, and in total yield at Ridgetown was consistent with other research (Burket et al 1997;Mullins et al 1999;Griffin et al 2000;Cline and Silvernail 2002;Teasdale et al 2008). Similar to our study, Mullins et al (1999), Burket et al (1997), and Griffin et al (2000) observed variable weather during their studies, including hot dry years. As well, with the exception of the study by Teasdale et al (2008), which was conducted on loamy sand soil, the other studies (Burket et al 1997;Mullins et al 1999;Griffin et al 2000;Cline and Silvernail 2002) occurred predominately on silt loam soils and therefore were less sandy than the soils in our study.…”

“…Similar to our study, Mullins et al (1999), Burket et al (1997), and Griffin et al (2000) observed variable weather during their studies, including hot dry years. As well, with the exception of the study by Teasdale et al (2008), which was conducted on loamy sand soil, the other studies (Burket et al 1997;Mullins et al 1999;Griffin et al 2000;Cline and Silvernail 2002) occurred predominately on silt loam soils and therefore were less sandy than the soils in our study. Similar to our study, effects of cover crops on sweet corn yield showed mixed and often contrasting results depending on site-year (Carrera et al 2004;Malik et al 2008).…”

Yields and protein content of two cowpea varieties grown under different production practices in Limpopo province, South Africa

“…In 2006/07 season, the differences between the mean protein content of green pods obtained from Pan 311 and Red Caloona was significant. The higher values obtained in Pan 311 was probably because of its early maturity status and better nutrients uptake ability including nitrogen (Griffin et al, 2000). Neither cropping systems nor cowpea leaf pruning during the vegetative stage had significant effect on the protein content of cowpea green pods.…”

Reducing Energy Inputs in the US Food System

“…Other studies in both the USA and Ghana have shown that nitrogen yields from legumes planted the season before were between 100-200 kg/ha (Griffin et al 2000). In the organic systems at Rodale Farms in Pennsylvania, soil nitrogen levels were 43% compared to only 17% in conventional systems .…”