Sweet corn production and efficiency of nitrogen use in high cover crop residue

Abstract

-In the humid, temperate mid-Atlantic area of the USA, crop production that leaves the soil uncovered can lead to undesirable soil and nutrient losses to the surrounding Chesapeake Bay watershed. To cope with this issue, winter annual cover crops could provide soil cover both during winter months and, as surface residue in no-tillage cropping systems, during summer months. Legume cover crops such as hairy vetch can produce abundant biomass and N by the time summer crops are planted in spring. Although N mineralized from a legume cover crop can contribute to meeting the N requirement of crops such as corn, it also may not be used efficiently by crops and could be lost into the local environment. This research was conducted to determine whether hairy vetch or a hairy vetch-rye mixture that was allowed to produce high levels of biomass with a high N content (200 to 250 kg/ha) could meet the N requirements of no-tillage sweet corn and to determine the efficiency of N use relative to that of fertilizer N. Our results show that marketable yield of sweet corn was approximately doubled by hairy vetch in 2 of 3 years compared to an unfertilized, no-cover crop control. However, in 2 of 3 years, hairy vetch and the vetch-rye mix reduced yield by 19 and 34%, respectively, compared to a no-cover crop control with fertilizer N. Reduced plant population that reduced the number of ears per ha accounted for the yield reduction by these cover crops compared to the fertilized no-cover crop control. Fertilizer N was 1.5 to 2 times more efficient than hairy vetch at producing sweet corn ear mass per unit of N input but combinations of fertilizer N with cover crops were less efficient than either alone. Results suggest that growing sweet corn without tillage in high biomass levels of cover crops can interfere with crop establishment, reduce the efficiency of crop production, and allow for potentially high N losses into the environment. cover crops / nitrogen use efficiency / sweet corn / Zea mays L. / hairy vetch / Vicia villosa Roth / rye / Secale cereale L.

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.…”

“…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).…”

“…At Ridgetown, N treatment had no effect on sweet corn shoot biomass production at any time during the sweet corn season, likely due to high plant available N over the growing season (data not shown). Other research has also shown that fertilization does not necessarily lead to increased sweet corn biomass or plant populations (Dyck and Liebman 1994;Mullins et al 1999;Teasdale et al 2008). Similarly, others have found that neither cover crops (Teasdale et al 2008;Burgos and Talbert 1996) nor N treatment (Isse et al 1999) had an effect on sweet corn biomass.…”

Nine-year results on maize and processing tomato cultivation in an organic and in a conventional low input cropping system

“…Only for tomato marketable yield of 2009 and 2010 variations were clearly due to causes other than N availability: in 2009 it was conventional tomato that yielded less that potential due to a bad crop establishment; this because a 50 mm rainfall occurred during seedbed preparation impeding an adequate soil loosening which, on the contrary, could be obtained in the organic soil thanks to green manure biomass incorporated just before; in 2010 the marketable yield loss of organic tomato was due to an unsuccessful mechanical control of weed infestation and to a higher proportion of unmarketable fruits over conventional tomato (36% vs 20% of total fruit weight in ORG and LOW, respectively). A lower yield was reported in several studies where maize was grown organically (Mischler et al, 2010;Wortman et al, 2012) or fertilized by cover crops (Tonitto et al, 2006;Teasdale et al, 2008) and was often explained by the lower and variable N supply from green manures. In turn, the growth and Ndfa accumulation of green manures was affected by fall winter climate and was actually much variable.…”

“…These two crops differ much for N uptake capacity (also due to different plant spacing), total amount and timing of N need, effect of N on crop yield (also due to different requirements for marketable yield between a cereal and a vegetable). Maize is a high N demanding crop with early spring sowing and green manures may not guarantee an adequate N availability especially in early growth phases, with consequent lower growth and grain yield (Benincasa et al, , 2010Teasdale et al, 2008). Processing tomato may better use organic N sources in virtue of its lower and later N need due to its mid spring transplanting date .…”