PHOSPHORUS CONTENT IN SOIL IN RELATION TO FULVIC ACID CARBON FRACTION.

Autor: Zalba, Pablo, Peinemann, Norman
Předmět:
Zdroj: Communications in Soil Science & Plant Analysis; 2002, Vol. 33 Issue 19/20, p3737, 8p
Abstrakt: The fulvic acid fraction is considered an important constituent of soil organic matter and is sensitive to management regimes and tillage impact. Both humic acids (HA) and fulvic acids (FA) are able to form metal complexes which bind appreciable amounts of phosphate or phosphorus (P) species. The aim of the present study is to evaluate the fulvic acid carbon content of agricultural soils in Argentina and to explore the possible relationship between acid carbon (PC) content and the level of available P in the soil. A total of 74 surface samples of Hapludolls and Haplustolls covering areas with decreasing levels of annual rainfall were analyzed. It was found that soils with FC content >5.5 g kg[sup -1] exhibited available P levels >30 mg kg[sup -1], whereas available P levels < 20 mg kg[sup -1] were related to FC contents < 4.0 g kg[sup -1]. Soils with high FC content thus currently have adequate P without supplementing it in the form of fertilizer. A more meaningful relationship is found between the FC fraction and available P than between P status and total organic carbon of soil. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index