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Mitigating nitrogen pollution with under-sown legume-grass cover crop mixtures in winter cereals.
Morris, Andrew H; Isbell, Sarah A; Saha, Debasish; Kaye, Jason P.
Afiliación
  • Morris AH; Institute of Ecology and Evolution, Dep. of Biology, Univ. of Oregon, Eugene, OR, 97403, USA.
  • Isbell SA; Dep. of Ecosystem Science and Management, The Pennsylvania State Univ., University Park, PA, 16802, USA.
  • Saha D; Biosystems Engineering and Soil Science, The Univ. of Tennessee, Knoxville, TN, 37996, USA.
  • Kaye JP; Dep. of Ecosystem Science and Management, The Pennsylvania State Univ., University Park, PA, 16802, USA.
J Environ Qual ; 50(2): 324-335, 2021 Mar.
Article en En | MEDLINE | ID: mdl-33410518
Nitrogen (N) pollution from N inputs to agricultural soils contributes to widespread eutrophication and global climate change. One period susceptible to N losses is between winter grain harvest in summer and corn planting in spring in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.]-winter grain rotation. Cover crops used to immobilize N during this period often depend on tillage, which can exacerbate N losses. Therefore, we evaluated whether reduced-till cover crops could decrease nitrate (NO3 - ) leaching and nitrous oxide (N2 O) emissions during this period. We tested this strategy in a cropping systems experiment on a 4-ha plot in central Pennsylvania over 2 yr. This experiment compared a clover (Trifolium pratense L.)-timothy (Phleum pratense L.) cover crop no-till underseeded into a standing spelt crop with a vetch (Vicia villosa Roth)-triticale (× Triticosecale Wittm. ex A. Camus) cover crop established with tillage after spelt harvest. These systems were compared based on fortnightly N2 O emissions using static chambers (n = 4 per six sample dates) and potential NO3 - leaching using anion resin bags (n = 4 per system per year). Reduced-till cover crops minimized peak N2 O emissions during the fall compared with tilled cover crops. However, reduced-till cover crops did not decrease potentially leachable NO3 - relative to tilled cover crops despite decreases in soil inorganic N. Cover crop N isotopes revealed that clover N may have mineralized and leached over the winter. Our results suggest that reduced-till cover crops can decrease N2 O emissions to mitigate the climate impact of agriculture but that winter-hardy cover crops should be chosen to mitigate leaching.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Grano Comestible / Nitrógeno País/Región como asunto: America do norte Idioma: En Revista: J Environ Qual Año: 2021 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Grano Comestible / Nitrógeno País/Región como asunto: America do norte Idioma: En Revista: J Environ Qual Año: 2021 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos