Soil phosphorus dynamics as affected by Congo grass and P fertilizer
Data
2014-07-01
Autores
Rosolem, Ciro Antonio [UNESP]
Merlin, Alexandre [UNESP]
Bull, Júlio Cesar Longo [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Univ Sao Paolo
Resumo
Some plant species can change soil phosphorus (P) availability and this may be an important tool in managing tropical high fixing phosphorus soils. An experiment was conducted to evaluate phosphorus transformations in the soil and phosphatase activity during periods of Congo grass (Brachiaria ruziziensis, Germain et Evrard) growth in two tropical soils receiving 20, 40, 80, 160 mg dm(-3) of inorganic P. Plants were grown for 84 days in 8-L pots. Acid phosphatase activity, P in the microbial mass, soil organic and inorganic P and P accumulation by Congo grass were evaluated. Phosphorus fertilization increased soil P availability, Congo grass yields and P accumulation in the plant. On average, less labile P forms in the soil were not changed by Congo grass; however, the P in the soil extracted with HCl (P-Ca - non labil form) decreased. This decrease may have resulted from the combination of the presence of grass and phosphatase capacity to dissolve less available P in the soil. Thus, soil exploration by Congo grass roots and the subsequent extraction of calcium phosphate may have increased the P concentration in the plant tissue. Despite the decrease in the P extracted from the soil with HCl resulting in increased labile P forms in the soil, the effect of Congo grass on the availability of P depends on the soil type.
Descrição
Palavras-chave
Phosphatase, Soil fertility, Crop rotation, Brachiaria
Como citar
Scientia Agricola. Cerquera Cesar: Univ Sao Paolo, v. 71, n. 4, p. 309-315, 2014.