Assessing extractable soil phosphorus methods in estimating phosphorus concentrations in surface run‐off from Calcic Hapludolls

Abstract

Understanding soil test phosphorus (STP) and surface run‐off phosphorus (P) relationships for soils is necessary for P management. The objective of the study was to evaluate the efficacy of various soil test indices to predict P losses in surface run‐off. Selected sites were subjected to in situ rainfall simulations according to the protocol of the National Phosphorus Research Project (NPRP, 2001). P from a composite of twenty‐four 2.0‐cm‐diameter core soil samples (0–5 cm) was extracted using the Olsen, Bray–Kurtz, Mehlich III, distilled water and 0.01 m calcium chloride procedures. All of these P extraction methods explained a significant amount of variability in surface run‐off total dissolved P [TP (<0.45)] (r2 ≥ 0.67; P ≤ 0.01), where 0.45 is the filter pore diameter in microns. Multiple regression models showed extractable P to be the best soil predictor of surface run‐off TP (<0.45) among the studied soils. Despite extraction method or soil type, extractable P was the best soil predictor of surface run‐off TP (<0.45). Either agronomic (0.92 ≤ r2 ≤ 0.96) or environmental (0.94 ≤ r2 ≤ 0.96) soil tests were effective in estimating surface run‐off TP (<0.45) in select Mollisols.

Evaluation of two management options to improve the water quality of Lake Brunner, New Zealand

“…The enhanced responsiveness of resinextractable P over Olsen P was probably a reflection of the inability of the Olsen test to account for P in minerals such as apatite found in RPR (Rajan et al 1996;Saggar et al 1990). Schindler et al (2009) have recently suggested that for predicting P loss in surface runoff, agronomic tests like Olsen P (Olsen et al 1954) are as good as water-soluble P tests (McDowell & Condron 2004), which were designed specifically for the task. However, the Olsen P data in Table 1 suggest that no difference in surface runoff P concentrations would exist between treatments.…”

A Potential Solution to Mitigate Phosphorus Release Following Clearfelling in Peatland Forest Catchments

“…Veresoglou and Fitter (1984) carried out a study on nutrient uptake in five coexisting grasses and found that H. lanatus and A. capillaris could uptake 16.9 and 2.7 mg TP (m 2 .day) -1 , respectively. As WEP has strong linear relationship with TP concentrations in the runoff (Schindler et al 2009) and has been proved to be a useful indicator of soluble P concentrations in peat soil runoff water (Daly and Styles 2005), it is expected that the reduction of WEP in the grass seeded plots could result in reduction of P runoff release.…”