title: Using simulated rainfall to evaluate field and indoor surface runoff phosphorus relationships.
abstract: While numerous studies have evaluated the efficacy of outdoor rainfall simulations to predict P concentrations in surface runoff, few studies have linked indoor rainfall simulations to P concentrations in surface runoff from agricultural fields. The objective of this study was to evaluate the capacity of indoor rainfall simulation to predict total dissolved P concentrations [TP(<0.45)] in field runoff for four dominant agricultural soils in South Dakota. Surface runoff from 10 residue-free field plots (2 m wide by 2 m long, 2-3% slope) and packed soil boxes (1 m long by 20 cm wide by 7.5 cm high, 2-3% slope) was compared. Surface runoff was generated via rainfall simulation at an intensity of 65 mm h(-1) and was collected for 30 min. Packed boxes produced approximately 24% more runoff (range = 2.8-3.4 cm) than field plots (range = 2.3-2.7 cm) among all soils. No statistical differences in either TP(<0.45) concentration or TP(<0.45) loss was observed in runoff from packed boxes and field plots among soil series (0.17 < P < 0.83). Three of four soils showed significantly more total P lost from packed boxes than field plots. The TP(<0.45) concentration in surface runoff from field plots can be predicted from TP(<0.45) concentration in surface runoff from the packed boxes (0.68 < r(2) < 0.94). A single relationship was derived to predict field TP(<0.45) concentration in surface runoff using surface runoff TP(<0.45) concentration from packed boxes. Evidence is provided that indoor runoff can adequately predict TP(<0.45) concentration in field surface runoff for select soils.
authors.affiliation: East Dakota Water Development District, 132 B Airport Drive, Brookings, SD 57006, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Guidry
authors.forename: F V
authors.initials: FV
authors.lastname: Schindler
authors.forename: D R
authors.initials: DR
authors.lastname: German
authors.forename: R H
authors.initials: RH
authors.lastname: Gelderman
authors.forename: J R
authors.initials: JR
authors.lastname: Gerwing
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D005308:Fertilizers; D006798:Housing; D006863:Hydrogen-Ion Concentration; D010758:Phosphorus / Q000032:analysis*; D011891:Rain; D012987:Soil / Q000032:analysis*; D012995:Solubility; D013023:South Dakota; D014872:Water Movements
chemical_list: D005308:Fertilizers; D012987:Soil; D010758:Phosphorus