The object of this study was to determine the amounts of nitrate (NO3-) and other nutrients leached from an intensively grazed pasture over 1 year. Concentrations of NH4+, NO3-, Ca2+, Mg2+, Na+, K+, SO42-, PO43-, and Cl-were measured in samples of water percolating through soil (Ruatangata friable clay) under cattle grazed pastures receiving 0 or 172 kg N/ha per year as urea. Elemental concentrations varied greatly with both site and time of collection. The equivalent concentrations of NO3-and Ca2+were highly correlated (r2= 0.96) and could be used for estimating the equivalent concentrations of the other ions. For each unit increase in the concentration of NO3-, the equivalent concentration of cations increased in the order: Ca Mg Na K. The amount of element leached was calculated as the product of measured concentration and estimated drainage volume. Leaching losses over 1 year (kg/ha nil-N treatment; kg/ha +N treatment) were thus estimated as N (88; 193); Ca (154; 216); Mg (32; 44); Na (71; 86); and K (14; 21). Rainfall and estimated drainage were 1840 and 985 mm respectively.
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