Phosphorus availability in soils amended with different phosphate fertilizers

• Published in: Communications in soil science and plant analysis 2006-02, Vol.37 (1-2), p.25-39
• Main Authors: Randhawa, P.S, Condron, L.M, Di, H.J, Sinaj, S, McLenaghen, R.D
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; buffering capacity; fertilizer application; fertilizer requirements; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; isotopic exchange kinetics; kinetics; Nitrogen, phosphorus, potassium fertilizations; nutrient availability; phosphates; phosphorus; reactive phosphate rock; rock phosphate; soil fertility; Soil science; soil treatment; Soil-plant relationships. Soil fertility. Fertilization. Amendments; topsoil; water solubility; water-soluble phosphorus
• ISSN: 0010-3624; 1532-2416
• DOI: 10.1080/00103620500403572

Accurate measurement and characterization of phosphate rock dissolution are important for a better understanding of phosphorus (P) availability in soils. An incubation study was carried out on two New Zealand topsoils (0-15 cm; high P buffering capacity Craigieburn and low P buffering capacity Templeton) amended with North Carolina phosphate rock (NCPR) and water-soluble phosphate (WSP) at 218 mg P kg(-1) (equivalent to 60 kg P ha(-1)). Isotopic exchange kinetics was carried out after 12 h and 28 days of incubation to characterize P availability. This study showed that sensitivity of capacity factors (r1/R, n) to explain changes in E1min values was affected by the P buffering capacity of the soils. The recovery of applied P in the E pool (Rec(inE)%) with extended incubation time was similar from the NCPR and WSP treatments (3.1-3.3%) in the Craigieburn soil compared with the Templeton soil in which Rec(inE)% values were greater in WSP (9%) than NCPR (1.3%) treatment. The higher values of P derived from the applied P fertilizers in the E pool (Pdff(inE)%>80%) suggested that the NCPR application in both soils would be efficient for increasing P availability to plants.