PHOSPHORUS CONTENT IN SOIL IN RELATION TO FULVIC ACID CARBON FRACTION

• Published in: Communications in soil science and plant analysis Vol. 33; no. 19-20; pp. 3737 - 3744
• Main Authors: Zalba, Pablo, Peinemann, Norman
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01-12-2002; Taylor & Francis
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Mineral components. Ionic and exchange properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Soil science; South America; Argentina; America; Organic matter; Carbon compound; Soil tillage; Available nutrient; Phosphorus; Mollisols; Inorganic element; Soil management; Carbon content; Nutrient; Chemical composition; Chemical concentration; Fulvic acid
• ISSN: 0010-3624; 1532-2416
• DOI: 10.1081/CSS-120015918

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 (FC) 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
−1
exhibited available P levels >30 mg kg
−1
, whereas available P levels <20 mg kg
−1
were related to FC contents <4.0 g kg
−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.