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Phosphorus fertilizer form affects phosphorus loss to waterways: a paired catchment study
Author(s) -
McDowell R. W.,
Littlejohn R. P.,
Blennerhassett J. D.
Publication year - 2010
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.2010.00289.x
Subject(s) - phosphorus , streams , fertilizer , phosphorite , environmental science , phosphate fertilizer , phosphate , hydrology (agriculture) , agronomy , zoology , chemistry , biology , geology , geotechnical engineering , organic chemistry , computer science , computer network
Two catchments were used to test the hypothesis that using reactive phosphate rock (RPR), a low water soluble fertilizer, instead of superphosphate, could decrease phosphorus (P) export in streams. The sheep‐grazed catchments, each ca. 12 ha in size, received 20–25 kg P/ha either as RPR or superphosphate for 3 yr. Filterable (<0.45 μm) reactive P (FRP) and total P (TP) in stream samples were then compared against two subsequent years when both catchments received 20 kg P/ha as superphosphate. On average, during the 5‐yr study, loads of FRP and TP in stream flow were low (110 g FRP/ha and 358 g TP/ha), typical of dry sheep‐grazed hill country. However, FRP (58%) and TP (38%) in stream flow were significantly less when RPR was applied instead of superphosphate. Where appropriate climatic and soil conditions exist to maintain agronomic targets, RPR could be used to decrease P export in streams.