Open AccessRPR revisited (2): Long-term farmer experience helps define the role of RPR in grazed pastures
Author(s) -
M. A. Zaman,
B. F. Quin
Publication year - 2012
Publication title -
proceedings of the new zealand grassland association
Language(s) - English
Resource type - Journals
eISSN - 1179-4577
pISSN - 0369-3902
DOI - 10.33584/jnzg.2012.74.2866
Subject(s) - eutrophication , context (archaeology) , agriculture , surface runoff , phosphorus , phosphorite , term (time) , quality (philosophy) , water quality , environmental science , business , environmental resource management , natural resource economics , environmental planning , geography , nutrient , economics , ecology , philosophy , materials science , physics , archaeology , epistemology , quantum mechanics , metallurgy , biology
The commercial introduction of reactive phosphate rock (RPR) to the New Zealand market in 1987 was the subject of much dispute regarding its efficacy, and the differing interpretations of field trial results. Twenty-five years on, it was considered time to seek the views of farmers who are long-term users of RPR, across a wide range of geographic, soil type, fertility, climate and farming operations. The fact that the farmers interviewed have all been farming successfully with RPR for many years enables conditions suitable for RPR use to be identified more clearly compared to earlier advice. This progress is discussed in the context of utilising the proven reduced phosphorus (P) run-off with RPR to reduce P eutrophication in P-sensitive catchments. Key words: Reactive phosphate rock, RPR, superphosphate, SSP, long-term use, phosphorus runoff, eutrophication, water quality, recommendations