About Us | Help Videos | Contact Us | Subscriptions
 

Members of ASA, CSSA, and SSSA: Due to system upgrades, your subscriptions in the digital library will be unavailable from May 15th to May 22nd. We apologize for any inconvenience this may cause, and thank you for your patience. If you have any questions, please call our membership department at 608-273-8080.

 

Institutional Subscribers: Institutional subscription access will not be interrupted for existing subscribers who have access via IP authentication, though new subscriptions or changes will not be available during the upgrade period. For questions, please email us at: queries@dl.sciencesocieties.org or call Danielle Lynch: 608-268-4976.

Abstract

 

This article in JEQ

  1. Vol. 29 No. 1, p. 105-110
     
    Received: Aug 28, 1998


    * Corresponding author(s): nick.hesketh@bbsrc.ac.uk
 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2134/jeq2000.00472425002900010013x

Development of an Indicator for Risk of Phosphorus Leaching

  1. N. Hesketh * and
  2. P. C. Brookes
  1. Soil Science Dep., IACR-Rothamsted, Harpenden, Hertfordshire, AL5 2JQ UK.

Abstract

Abstract

Previous work showed that at soil P concentrations below 57 mg 0.5 M NaHCO3-extractable P (Olsen P) kg−1 soil, little P was found in drainage waters collected from tile drains set 65 cm below the soil surface in soils from the Broadbalk Continuous Wheat Experiment. Above this soil P concentration (termed the Change-Point) both total P and molybdate-reactive P (MRP) in drainage waters were linearly related to soil Olsen P concentrations. We now need to know if the Change-Point measured on Broadbalk occurs on other soils, and if so, whether a common value applies or if it varies depending upon soil type, management, and site hydrology. We investigated the possibility of 0.01 M CaCl2-extractable P being an indicator of the Change-Point. In all the soils studied, we found that the dynamics of P solubility in CaCl2 closely resembled the dynamics of P solubility in drainage waters of Broadbalk, since very distinct Change-Points occurred under both conditions. However, Change-Points measured following extraction with CaC2 varied widely between soils, from 10 to 119 mg Olsen P kg−1 soil. Lysimeter studies showed, with some exceptions, good agreement between Change-Points measured in drainage water and in 0.01 M CaCl2. We therefore suggest that this approach may provide a valid indicator of the soil Olsen P concentration at which significant amounts of P begin to leach from soil to water, provided preferential pathways exist in the subsoil to permit P leaching down the soil profile in drainage water.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .