Evaluation of Phosphorus Transport in Surface Runoff from Packed Soil Boxes

Abstract

Evaluation of phosphorus (P) management strategies to protect water quality has largely relied on research using simulated rainfall to generate runoff from either field plots or shallow boxes packed with soil. Runoff from unmanured, grassed field plots (1 m wide x 2 m long, 3-8% slope) and bare soil boxes (0.2 m wide and 1 m long, 3% slope) was compared using rainfall simulation (75 mm h(-1)) standardized by 30-min runoff duration (rainfall averaged 55 mm for field plots and 41 mm for packed boxes). Packed boxes had lower infiltration (1.2 cm) and greater runoff (2.9 cm) and erosion (542 kg ha(-1)) than field plots (3.7 cm infiltration; 1.8 cm runoff; 149 kg ha(-1) erosion), yielding greater total phosphorus (TP) losses in runoff. Despite these differences, regressions of dissolved reactive phosphorus (DRP) in runoff and Mehlich-3 soil P were consistent between field plots and packed boxes reflecting similar buffering by soils and sediments. A second experiment compared manured boxes of 5- and 25-cm depths to determine if variable hydrology based on box depth influenced P transport. Runoff properties did not differ significantly between box depths before or after broadcasting dairy, poultry, or swine manure (100 kg TP ha(-1)). Water-extractable phosphorus (WEP) from manures dominated runoff P, and translocation of manure P into soil was consistent between box types. This study reveals the practical, but limited, comparability of field plot and soil box data, highlighting soil and sediment buffering in unamended soils and manure WEP in amended soils as dominant controls of DRP transport.

Transport of dissolved trace elements in surface runoff and leachate from a Coastal Plain soil after poultry litter application

“…Lysimeters were subjected to 1-hour rainfall simulations (61 mm [2.4 in] precipitation) on May 1 and June 12, 2008 (15 and 42 days after litter application), using a modified version of the National Phosphorus Research Project protocol (Kleinman et al 2004). In between simulated rainfall events, lysimeters were irrigated by hand semiweekly (11 events), with the total irrigation depth approximating the 30-year average precipitation for the research site during March and April.…”

Do plot studies generate "directionally" correct assessments of field-level phosphorus losses?

“…Thus, one could argue that to compare data from NPRP plots to field-or watershed-scale data would be to make interpolations far beyond what the NPRP was intended to represent. There have been a few studies to examine the spatial scaling influences of box-and plot-scale simulation work using the NPRP protocols (Sharpley and Kleinman 2003;Kleinman et al 2004;Guidry et al 2006). Kleinman et al (2004) and Guidry et al (2006) ).…”

“…There have been a few studies to examine the spatial scaling influences of box-and plot-scale simulation work using the NPRP protocols (Sharpley and Kleinman 2003;Kleinman et al 2004;Guidry et al 2006). Kleinman et al (2004) and Guidry et al (2006) ). These studies compared P loss parameters for soils from the same fields/catchments, whereas small-scale studies are often used to develop or calibrate models based on data from one field or catchment, which is then applied to another catchment.…”

Runoff and Nutrient Losses from Constructed Soils Amended with Compost

“…Previous reports indicated runoff concentrations and losses of dissolved P were directly related to concentrations in top-dressed amendments [11,12]. Incorporation of CDM or CMB at volume-based rates increased concentrations of extractable soil P and dissolved P in runoff [13][14][15]. Variation of nutrient concentration and form among composted materials, including CDM and CMB, and amended soils needs to be evaluated in relation to nonpoint-source losses [12,16].…”