Phosphorus in runoff from two highly weathered soils of the tropics

• Published in: Canadian journal of soil science 2011-05, Vol.91 (2), p.267-277
• Main Authors: Ramírez-Ávila, John, Sotomayor-Ramírez, David, Martínez-Rodríguez, Gustavo, Pérez-Alegría, Luís
• Format: Article
• Language: English
• ISSN: 0008-4271; 1918-1841
• DOI: 10.4141/cjss10064

Ramírez-Ávila, J. R., Sotomayor-Ramírez, D., Martínez-Rodríguez, G. A. and Pérez-Alegría, L. R. 2011. Phosphorus in runoff from two highly weathered soils of the tropics. Can. J. Soil Sci. 91: 267–277. Agricultural fields with high soil phosphorus (P) content are important contributors to surface water degradation. Two consecutive simulated rainfall events were conducted on two Ultisols previously amended with inorganic P fertilizer or broiler litter. Soil test P (Bray 1 and Olsen) levels evaluated ranged from 1 to 350 mg kg −1 . Surface runoff concentrations of total P (TP) and dissolved P (DP) generated by a 30-min runoff event were quantified. Runoff DP concentrations ranged from 0.08 to 3.98 mg L −1 in fertilizer P-amended soils and from 0.08 to 4.93 mg L −1 in broiler litter-amended soils. A single exponential model adequately described the relationships between soil test P and DP concentrations in runoff. For each soil, the soil test P-DP concentration relationships were positively influenced by soil organic matter and negatively influenced by antecedent soil moisture (P