|Torbert, Henry - Allen|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2002
Publication Date: 11/10/2002
Citation: Torbert, H.A., Daniel, T.C., and Lemunyon, J.L. Soil test phosphorus sampling depth effect on phosphorus runoff loss prediction. Agronomy Abstracts. 2001. CD-ROM computer file.
Technical Abstract: A study was initiated to investigate the relationship between soil test P (STP) and depth of sampling with P losses in runoff. Four soil types were chosen, two calcareous soils and two non-calcareous soils. Soil and runoff samples were collected from each of the four soils in permanent pasture exhibiting a wide range of P levels due to prior manure applications. Soil sampling depths consisted of 0-2.5, 0-5, and 0-15 cm. The STP was determined by Mehlich III and distilled water extraction techniques. Simulated rain was used to produce runoff which was collected for 30 min. Good relationships were derived between STP and runoff losses of P for all four soil types, as indicated by relatively high r2 values. The data indicates that sampling at the 0-5 cm depth may result in the best results both for limiting management problems and by increasing the likelihood of developing reliable predictive equations across large number of soil types.