Scholarlink

<p>Cover crops (CCs) can reduce nitrogen (N) leaching in general compared to bare soil. However, there is little understanding of how N from commodity crops and CC is distributed and partitioned in different biogeochemical cycles. The aim of this study was to identify the importance of different N pools, including soil, water and plant, for partitioning N in corn (<i>Zea mays</i> L.)–soybean (<i>Glycine max</i> L. Merr.) rotation with legume and non-legume CCs using the <sup>15</sup>N tracer technique. The experimental site was started in 2013 with cereal rye (<i>Secale cereale</i> L.) CC following corn and hairy vetch (<i>Vicia villosa</i> Roth.) CC following soybean [corn–cereal rye–soybean–hairy vetch (C–R–S–H)], under no-till practice. <sup>15</sup>N-labeled urea was applied to microplots in 2017. Soil, leachate water and biomass samples were collected during the commodity and CC seasons. During the 2017 corn growing season, soil samples at 15–30&#xa0;cm depth collected 7 and 21&#xa0;days after planting had 13.13 and 3.68&#xa0;kg&#xa0;ha<sup>−1</sup> greater <sup>15</sup>N-recovery in CC than no CC treatment, indicating increased vertical N movement. During the cereal rye season, no CC plots had greater <sup>15</sup>N-recovery in water than in CC plots, supporting the positive behavior of non-legume CCs scavenging residual-N. In contrast, during the hairy vetch season, CC plots had greater <sup>15</sup>N-recovery in water than no CC. Total fertilizer recovery in corn plant biomass (grain + silage) for CC rotation was 99.7&#xa0;kg&#xa0;N&#xa0;ha<sup>−1</sup>, of which 27.7&#xa0;kg&#xa0;N&#xa0;ha<sup>−1</sup> was derived from applied <sup>15</sup>N fertilizer, whereas 72.0&#xa0;kg&#xa0;N&#xa0;ha<sup>−1</sup> was derived from residual soil N. This indicated that most of the N uptake by plants in a season was residual-N from soil compared to applied fertilizer N. Recovery of applied fertilizer N in soil–water–plant pools after 2&#xa0;years of crop rotation with CC showed that 27.3% was utilized by corn biomass and 28.3% removed in grain, 5.8% utilized by cereal rye, 4.4 and 5.9% were recovered in soybean seed and straw, 1.6% in hairy vetch biomass, 7.6% in soil, 6.5% in water through leaching and 12.1% was unrecovered which is assumed to be lost in the atmosphere or as deep percolation.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

15Nitrogen urea fertilizer fate in soil–water–plant pools for corn–soybean rotation with grass and legume cover crops

  • 期刊论文

  • 发表日期：

    2025年9月2日

查看全文
  • Gurbir Singh,
  • Ashani Thilakarathne,
  • Karl Williard,
  • Jon Schoonover

摘要

Cover crops (CCs) can reduce nitrogen (N) leaching in general compared to bare soil. However, there is little understanding of how N from commodity crops and CC is distributed and partitioned in different biogeochemical cycles. The aim of this study was to identify the importance of different N pools, including soil, water and plant, for partitioning N in corn (Zea mays L.)–soybean (Glycine max L. Merr.) rotation with legume and non-legume CCs using the 15N tracer technique. The experimental site was started in 2013 with cereal rye (Secale cereale L.) CC following corn and hairy vetch (Vicia villosa Roth.) CC following soybean [corn–cereal rye–soybean–hairy vetch (C–R–S–H)], under no-till practice. 15N-labeled urea was applied to microplots in 2017. Soil, leachate water and biomass samples were collected during the commodity and CC seasons. During the 2017 corn growing season, soil samples at 15–30 cm depth collected 7 and 21 days after planting had 13.13 and 3.68 kg ha−1 greater 15N-recovery in CC than no CC treatment, indicating increased vertical N movement. During the cereal rye season, no CC plots had greater 15N-recovery in water than in CC plots, supporting the positive behavior of non-legume CCs scavenging residual-N. In contrast, during the hairy vetch season, CC plots had greater 15N-recovery in water than no CC. Total fertilizer recovery in corn plant biomass (grain + silage) for CC rotation was 99.7 kg N ha−1, of which 27.7 kg N ha−1 was derived from applied 15N fertilizer, whereas 72.0 kg N ha−1 was derived from residual soil N. This indicated that most of the N uptake by plants in a season was residual-N from soil compared to applied fertilizer N. Recovery of applied fertilizer N in soil–water–plant pools after 2 years of crop rotation with CC showed that 27.3% was utilized by corn biomass and 28.3% removed in grain, 5.8% utilized by cereal rye, 4.4 and 5.9% were recovered in soybean seed and straw, 1.6% in hairy vetch biomass, 7.6% in soil, 6.5% in water through leaching and 12.1% was unrecovered which is assumed to be lost in the atmosphere or as deep percolation.