Please use this identifier to cite or link to this item:
http://www.alice.cnptia.embrapa.br/alice/handle/doc/1120008Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.author | SMYTH, T. | |
| dc.contributor.author | CRAVO, M. da S. | |
| dc.date.accessioned | 2025-03-21T15:27:58Z | - |
| dc.date.available | 2025-03-21T15:27:58Z | - |
| dc.date.created | 2020-02-07 | |
| dc.date.issued | 1990 | |
| dc.identifier.citation | Agronomy Journal, v. 82, n. 2, p. 309-312, Mar./Apr. 1990. | |
| dc.identifier.uri | http://www.alice.cnptia.embrapa.br/alice/handle/doc/1120008 | - |
| dc.description | Phosphorus soil test interpretations in the Brazilian Amazon currently do not account for differences in P requirements among crops and lack information on the changes in available soil P per unit of applied fertilizer P. A long-term P experiment in a Xanthic Hapludox near Manaus, Brazil was used to determine soil and leaf P critical levels for corn (Zea mays L.) and cow pea (Vigna unguiculata L.). A total of six corn crops were planted in annual rotation with five crops of cowpea during five consecutive years. Critical levels were established by a segmented linear regression, a linear plateau, of relative crop yields on soil test or leaf P concentrations for each crop species. Mehlich 1 (1:10) critical P levels were 6 and 8 mg kg for corn and cowpea, respectively. Relationships between soil test P and crop yields were similar for fertilizer P placement as either broadcast and/or frequent bands. Fertilizer P required to raise the initial Mehlich 1 soil P to the critical levels were 41 and 60 kg P ha for corn and cowpea, respectively. Higher amounts of P were extracted by Bray 1 than by Mehlich 1, but both extractants were effective in relating available soil P to yield and applied fertilizer P. Critical foliar P concentrations for corn and cowpea were 1.6 and 1.8 g kg ', respectively. Higher soil and leaf P critical levels for cowpea relative to corn were attributed to greater P requirements for plants depending on symbiotic N2 fixation for their N supply. | |
| dc.language.iso | eng | |
| dc.rights | openAccess | |
| dc.title | Critical phosphorus levels for corn and cowpea in a Brazilian Amazon Oxisol. | |
| dc.type | Artigo de periódico | |
| dc.subject.thesagro | Zea Mays | |
| dc.subject.nalthesaurus | Corn | |
| riaa.ainfo.id | 1120008 | |
| riaa.ainfo.lastupdate | 2025-03-21 | |
| dc.identifier.doi | https://doi.org/10.2134/agronj1990.00021962008200020027x | |
| dc.contributor.institution | MANOEL DA SILVA CRAVO, UEPAE DE MANAUS. | |
| Appears in Collections: | Artigo em periódico indexado (CPAA)  | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| smyth1990-1.pdf | 123.56 kB | Adobe PDF |  View/Open |
