|
|
|
|
|
| Santos, Danilo Rheinheimer; UFSM; Martinazzo, Rosane; UFRGS; Gatiboni, Luciano Colpo; UDESC; Kaminski, João; UFSM; Silva, Leandro Souza da; UFSM. |
| Em solos com elevado grau de intemperismo, a imobilização temporária de fósforo pela biomassa microbiana do solo (BMS) pode ser um mecanismo de retardamento das reações de adsorção. O objetivo do presente trabalho foi avaliar a amplitude no fósforo microbiano (Pm) em um Argissolo em pastagem nativa submetida à roçada, introdução de forrageiras exóticas e adubadas com fertilizantes fosfatados. O estudo foi desenvolvido a partir de um experimento instalado em 1997 que constava de cinco tratamentos de fosfato e calagem (testemunha sem fósforo; hiperfosfato de gafsa; superfosfato triplo; superfosfato triplo + calcário e superfosfato simples + calcário), distribuídos em quatro blocos ao acaso. Em junho de 2002, a pastagem nativa remanescente foi roçada, semeada... |
|
Palavras-chave: 5.01.00.00-9 Agronomia biomassa microbiana; Imobilização; Adubos fosfatados; Pastagens nativas; Disponibilidade de fósforo. microbial biomass; Immobilization; Phosphate fertilizers; Natural pasture; Phosphorus availability. |
| Ano: 2008 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/5319 |
| |
|
|
| Vendrame,Pedro R.S.; Brito,Osmar R.; Guimarães,Maria F.; Martins,Éder S.; Becquer,Thierry. |
| The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55% of Brazilian beef production. Previous investigations have shown that about 70-80% of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1) a surface horizon (0.0-0.2 m) in order to evaluate its fertility and acidity status for pasture, and (2) a subsurface horizon (0.6-0.8 m), used for classification. Most... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cation exchange capacity; Exchangeable aluminum; Phosphorus availability; Soil degradation; Total carbon. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000400026 |
| |
|
|
| Brouwere,Katleen De; Thijs,Ann; Hens,Maarten; Merckx,Roel. |
| This study investigated the different forms and availability of P in soil profiles from temperate forests in southern Chile (two sites: Nothofagus obliqua (Mirb.) Bl. and Nothofagus betuloides (Mirb.) Oerst.) and Flanders, Belgium (two sites: Pinus nigra Arnold and Betula pendula Roth). Soils were sampled according to genetic horizonation and analysed for organic matter, oxalate-extractable P, Al and Fe, total inorganic P and total organic P. Phosphorus availability was assessed using an isotopic exchange technique and anion exchange membranes. The total P content was higher for the Chilean andosols and remained relatively high in the whole soil profile (1413-187 mg P kg-1) whereas total P decreased sharply in the lower horizons of the Flemish podzols... |
| Tipo: Journal article |
Palavras-chave: Andosols; Phosphorus availability; Podzols. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432003000100004 |
| |
|
| |
|
|
| Luchese,Eduardo Bernardi; Lenzi,Ervim; Favero,Luzia Otília Bortotti; Loubak,Luceide Heloisa. |
| Phosphorus collectors made from filter paper and synthetic cloth, were tested to evaluate their feasibility of determining the need for phosphate application. The collectors were coated with two types of oxides, iron oxide and aluminium oxide. The capacity of the collectors was tested by placing them in a 2 mL of solution containing phosphorus (PO4(3-)) in the concentration of 0.0, 1.00, 3.00, 5.00, 7.00, 9.00 and 11.00 µ g.mL-1, respectively, after which they were placed in contact with four types of soil (LBa, LRd, LEd and Ca) and incubed for 0.0 and 24 h. In this test the soils were kept at a humidity equivalent to 150 mmHg suction. The amount of phosphorus extracted from the solutions was tested at intervals between 0,0 and 11.0 µ g of phosphorus/mL.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphorus; Phosphorus availability; Phosphorus diffusion; Phosphorus extraction. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000200006 |
| |
|
|
| Drouillon,M.; Merckx,R.. |
| Exudation of low molecular weight carboxylates is an important phosphorus (P) acquisition strategy for plants in strongly P-fixing soils. The effect of citrate exudation on P availability was studied in five acid soils with a large organic matter content and a low available P pool. The amount of molybdate reactive P extracted by citric acid 10 mM (0.1-2 mg kg-1) was larger than the molybdate reactive P (MRP) extracted by CaCl2 10-3 M (0.007-0.07 mg kg-1). Both extractants were adjusted to soil pH prior to extraction. Also, the total P content of citric acid extracts (2-44 mg kg-1) far exceeded the total P content of CaCl2 (0.2-1.5 mg kg-1). However, ratios of MRP to total dissolved P (TDP) remained constant. When citric acid was added to the CaCl2-extracts... |
| Tipo: Journal article |
Palavras-chave: Andosols; Citric acid; Phosphorus availability. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432003000100009 |
| |
|
|
|
