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The effects of lime (Ca(OH)$) and disodium orthophosphate (Na$PO$H) added separately to selected Alfisols of the Acentejo Area (Tenerife, Canary Islands) have been studied. These soils have excessive acidity and a very high amount of exchangeable aluminium. Ca(OH)$ significantly (P = 0.01) increased soil pH (at 50% acid neutralization) and available P (at 100-200% acid neutralization), and decreased exchangeable Al (at 12.5% acid neutralization) white the addition of Na$PO$H did not significantly affect the available P, exchangeable Al, or the soil. It is recommended that Alfisol shouls be trated with lime to neutralize 100-200% of the acid using wetting and drying cycles during equilibration before adding P.

The soil-chemical characteristics of the vineyard of Acentejo's zona been studied. It is interisting to point out as the most outstanding characteristics, the acidity and the aluminium content of the soils, most of the soils have possibly affected of aluminium toxicity. Also, it have been given its contents of organic matter, available phosphorus, cation-exchange capacity, etc.

It has been one a fractioning of the organic phosphates according to the Krivonosova (1972) method on the horizons of several andosoils of Canary Islands. Is has been distinguisshed between the organic phosphates bound to compounds no-specific of the soil, fulvic acids, humic acids and humine. The dates obtained are studied in function of the sample's depth, evolution grade, vegetation. pH, percentage of sand, clay, carbon, nitrogen, alumine, A1/A1 + Si ratio and active inorganic phosphates of Fe, Al y Ca.