| Autor: |
Compaoré, E., Frossard, E., Sinaj, S., Fardeau, J.-C., Morel, J.-L. |
| Předmět: |
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| Zdroj: |
Communications in Soil Science & Plant Analysis; 2003, Vol. 34 Issue 1/2, p201, 23p |
| Abstrakt: |
Little information exists on the effect of land use management on isotopically exchangeable phosphate (P) in agricultural soils of Burkina Faso. The 0-10 cm layer of 30 soils was sampled in February 1994 in 3 regions of Burkina Faso (in the east near Kouaré, in the south center near Thiougou and in the center in Saria). Four samples were taken under natural vegetation, 6 samples were taken in agricultural soils which had been left as fallow under natural re-growth, 7 samples were taken from soils cultivated without any P inputs and 13 samples were obtained from soils that had received P inputs in inorganic and/or organic forms. The phosphorus status of these soils was estimated by their total P (Pt), the Bray-1 extraction and by the isotopic exchange kinetic method (E[SUB1min] the quantity of P isotopically exchangeable within 1 minute; E[SUB1min - 1day] the quantity of P isotopically exchangeable between 1 minute and 1 day; E[SUB1day - 3m] the quantity of P isotopically exchangeable between 1 day and three months; E[SUB>3m] the quantity of P which cannot be isotopically exchanged within 3 months). The amounts of total P, Bray-1 P, and P isotopically exchangeable within three months were found to be very low in the non-cultivated soils (under natural vegetation or under fallow) (median values were for: Pt 145.1; Bray-1 P 1.7; E[SUB1min] 0.16; E[SUB1min - 1day] 0.66; E[SUB1day - 3m] 1.34; E[SUB>3m] 143.5 mg P kg[SUP-1] soil). Cropping these soils without any P input resulted in Kouaré in a slight decrease in isotopically exchangeable P compared to the non-cultivated soils, while no effect was observed in Thiougou. As the estimated P balances suggested that the amount of P removed annually from the non-fertilized systems was close or even larger than the amount of P isotopically exchangeable within the time span of growth of an annual crops (3 months) or than the Bray-1 P content of the soil, it appeared that crops derived a significant amount... [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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