Recovery of Nitrogen‐15–Labeled Hairy Vetch and Fertilizer Applied to Corn

Abstract

Knowledge of the plant and soil recovery of nitrogen (N) from legume cover-crop residues and fertilizer is needed to improve corn N use efficiency. Nitrogen-15 labeled ammonium sulfate (AS) or hairy vetch (Vicia villosa Roth.) residues were applied at planting or AS at the six-leaf stage (sidedressing) to silage corn (Zea mays L.) grown in 38-cm-diameter by 60-cm-deep microplots containing a Jungdong loam (coarse loamy, mixed, mesic, Typic Udifluvents) in Suwon, Korea. The recovery of the labeled N sources was followed over 2 yr into the corn grain, stover, and the 0-to 15-cm depth of soil. Recovery of labeled N in the first-year corn was 32% of the planting-applied AS, 15% of planting-applied hairy vetch (HV) residues, and 46% of the sidedress AS. Conversely, the post-harvest soil contained more labeled N from the HV residues (38%) compared with planting AS (15%) or sidedress AS (14%). Total first-year recoveries of 15 N in crop plus soil after harvest were 47% for planting AS, 54% for HV residues, and 60% for sidedress AS, which are consistent for high summer rainfall (850 mm) climates. The second-year corn showed low availability of residual 15 N, although HV residues supplied about twice as much N (3.5%) as AS (1.5%). These results are consistent with other studies and show that AS is about twice as effective as legume residues in supplying N to a crop, whereas legume residues contribute about twice as much N to the soil.

Effect of 15n-labeled hairy vetch and nitrogen fertilization on maize nutrition and yield under no-tillage¹

“…Rochester & Peoples (2005) found higher BNF in hairy vetch than in this study, contributing to 90 % of the total N in the biomass. Giller & Wilson (1993) and Seo et al (2006) reported hairy vetch N accumulation and biomass production ranging from 100 to 200 kg ha -1 N and from 2.5 to 5.0 Mg ha -1 , respectively, similar to the values found in the present study.…”

“…On the other hand, the intensive use of mineral N fertilization for grain crops has been associated with the contamination of natural resources. Consequently, environmentally friendly husbandry practices have been investigated in the last decades, especially the use of legume cover crops to substitute mineral N fertilization partially or even completely (Amado et al, 2002;Seo et al, 2006).…”

“…Therefore, the main effect of hairy vetch on maize yield has been associated to an increased soil N availability . Howerver, studies with labeled hairy vetch showed that soil is the main destination of legume-derived N, rather than the direct crop uptake (Harris & Hesterman, 1990;Scivittaro et al, 2003;Seo et al, 2006).…”

“…The combination of the legume hairy vetch with complementary mineral N fertilization seems to be a promising strategy for maize nutrition which could save inputs, ensure competitive grain yields and decrease environmental risks (Scivittaro et al, 2003;Seo et al, 2006). The synergic interaction of these N sources could also induce an additional increase in maize yield, since the temporal pattern of N release from cover crop residues and by mineral fertilization is not the same Hadas et al, 2002).…”

15N-labeled nitrogen from green manure and ammonium sulfate utilization by the sugarcane ratoon

“…It seems that the residual N that is incorporated to the soil organic matter has a somewhat long turnover. Other authors have reported low recovery (about 3.5% of the N) by the second crop after sunn hemp cover crop (Silva et al, 2006) or hairy vetch (Vicia villosa Roth) plowed into the soil (Seo et al, 2006). Low recovery of residual N has also been observed for inorganic fertilizer sources: less than 3% of the N derived from fertilizers was taken up by soybeans (Glicine max (L) Merril) (Boaretto et al, 2004), maize (Silva et al, 2006), Seo et al (2006) or sugarcane (Saccharum spp.)…”