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Registro Completo |
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
22/10/2001 |
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Data da última atualização: |
22/10/2001 |
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Autoria: |
KANDA, K.; TAKAHASHI, M.; MIRANDA, C. H. B. |
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Título: |
Nitrogen cycling agropastoral systems |
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Ano de publicação: |
2001 |
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Fonte/Imprenta: |
In: KANNO, T.; MACEDO, M.C.M., ed. JIRCAS / EMBRAPA gado de corte international joint workshop on agropastoral system in South America. [Tsukuba]: JIRCAS, 2001. |
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Páginas: |
p.75-84. |
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Série: |
(JIRCAS Working Report, 19). |
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Idioma: |
Inglês |
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Notas: |
EMBRAPA-CNPGC and JIRCAS joint International Workshop on Agropastoral System in South America, held in Campo Grande, MS, Brazil, 1999. |
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Conteúdo: |
Agropastoral systems that combine soybeans and grass in a crop rotation have been proposed for sustaining grassland productivity in the low fertility soils of Brazilian Cerrados. We studied the nitrogen flow under an agropastoral system established in 1993 a Purple Red Latossol in Campo Grande, MS. Surface soil was collected from fields with continuous soybean cropping (6 years), soybeans cropped after 4 years of grassland, continuous grassland (6 years), grassland planted after 4 years of soybean cropping, a degraded grassland, and na original forest,; the samples were analyzed for N mineralization potential in the soil under the grasslands. The rate of N fixation in the soybeans was determined according to the N-difference method using a non-nodulating isoline, T201, as a control. The determined rate varied from 20 to about 50% of the total plant N. Most of the plant N was harvested out with the grains, leaving a negative N balance in the field.It was determined that the amount of N entering the system through rain water was small. Nitrate accumulated from the surface to a depth of 100 cm in the soil under the soybeans, indicating a potential leachingof nitrate. The estimated amount of leaching from the soybean fields, whereas there was large compared with that from the grasslands. A large negative N balance was measured in the soybean fields, whereas there was a small negative N balance in the grassland fields. |
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Palavras-Chave: |
Agropastoral systems; Ciclagem; Cycling; Sistema agropastoril. |
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Thesagro: |
Cerrado; Nitrogênio. |
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Thesaurus Nal: |
nitrogen. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02340naa a2200265 a 4500
001 1555567
005 2001-10-22
008 2001 bl uuuu u00u1 u #d
100 1 $aKANDA, K.
245 $aNitrogen cycling agropastoral systems
260 $c2001
300 $ap.75-84.
490 $a(JIRCAS Working Report, 19).
500 $aEMBRAPA-CNPGC and JIRCAS joint International Workshop on Agropastoral System in South America, held in Campo Grande, MS, Brazil, 1999.
520 $aAgropastoral systems that combine soybeans and grass in a crop rotation have been proposed for sustaining grassland productivity in the low fertility soils of Brazilian Cerrados. We studied the nitrogen flow under an agropastoral system established in 1993 a Purple Red Latossol in Campo Grande, MS. Surface soil was collected from fields with continuous soybean cropping (6 years), soybeans cropped after 4 years of grassland, continuous grassland (6 years), grassland planted after 4 years of soybean cropping, a degraded grassland, and na original forest,; the samples were analyzed for N mineralization potential in the soil under the grasslands. The rate of N fixation in the soybeans was determined according to the N-difference method using a non-nodulating isoline, T201, as a control. The determined rate varied from 20 to about 50% of the total plant N. Most of the plant N was harvested out with the grains, leaving a negative N balance in the field.It was determined that the amount of N entering the system through rain water was small. Nitrate accumulated from the surface to a depth of 100 cm in the soil under the soybeans, indicating a potential leachingof nitrate. The estimated amount of leaching from the soybean fields, whereas there was large compared with that from the grasslands. A large negative N balance was measured in the soybean fields, whereas there was a small negative N balance in the grassland fields.
650 $anitrogen
650 $aCerrado
650 $aNitrogênio
653 $aAgropastoral systems
653 $aCiclagem
653 $aCycling
653 $aSistema agropastoril
700 1 $aTAKAHASHI, M.
700 1 $aMIRANDA, C. H. B.
773 $tIn: KANNO, T.; MACEDO, M.C.M., ed. JIRCAS / EMBRAPA gado de corte international joint workshop on agropastoral system in South America. [Tsukuba]: JIRCAS, 2001.
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Embrapa Cerrados (CPAC) |
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