Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2002
Publication Date: November 10, 2002
Citation: Daniel, T.C., Torbert III, H.A. 2002. Arkansas and Texas. American Society of Agronomy Meetings, November 10-14, 2002, Indianapolis, Indiana. 2002 CDROM.
Dissolved phosphorus (DP) runoff concentrations from simulated rainfall studies in Arkansas and Texas will be used to demonstrate how the relationship between the level of phosphorus (P) in the soil and that contained in the runoff varies with the soil P extractant, soil hydrology, depth of soil sample, and whether the soil is calcareous or not calcareous. Soil extracts of distilled water gave the best correlation when compared to traditional soil test P (STP) extractants (Mehlich, Olsen, Bray-Kurtz P1, etc.). The relations (DP vs. STP) between soils varied depending on the hydrology of the soil. The importance of soil sample depth will also be shown. For the same level of STP in the soil, lower runoff DP concentrations occurred on calcareous soils when compared to non-calcareous soils. Field data will be presented on the use of exchange resins (filters) to produce source water for the rainfall simulator that approximates natural rainfall [low-buffered and low pH (5.5-6.0)]. Also, the relationship between STP and DP will be presented for two soil exhibiting wide ranges in STP levels (20 to 1,000 ppm Mehlich P).