My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in AJ

  1. Vol. 94 No. 1, p. 146-152
     
    Received: Apr 23, 2001
    Published: Jan, 2002


    * Corresponding author(s): thdao@anri.barc.usda.gov
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/agronj2002.1460

Post-Contract Land Use Effects on Soil Carbon and Nitrogen in Conservation Reserve Grasslands

  1. Thanh H. Dao *a,
  2. James H. Stieglerb,
  3. J. C. Banksc,
  4. Laurie B. Boerngend and
  5. Bud Adamse
  1. a USDA-ARS, 10300 Baltimore Ave., BARC-East, Beltsville, MD 20705
    b Dep. Plant and Soil Sci., Oklahoma State Univ., Stillwater, OK 74078
    c Dep. Plant & Soil Sci., Oklahoma State Univ., Altus, OK 73521
    d Usda-Nrcs, Beaver, Ok 73932
    e Usda-Nrcs, Altus, Ok 73521

Abstract

Carbon and N changes in highly erodible croplands (HELs) under the Conservation Reserve Program (CRP) and the effects of reverting to cultivation in semiarid regions are not well understood. The effects of four transitional production systems [Old World bluestem (Bothriochloa ischaemum L.)-unfertilized (OWBUF), Old World bluestem-fertilized (OWBF), conservation-tillage (CT), and no-till (NT) wheat (Triticum aestivum L.)] on soil C and N were determined in two CRP fields in western Oklahoma. Soil potentially mineralizable C (PMC) and N (PMN) were determined in cores collected before and after the reinitiation of cultivation in 1994 and in 1997. Compared with soils of the same series from adjoining cultivated fields, Old World bluestem (OWB) cover increased soil PMC, primarily in the 0- to 0.1-m depth of Dalhart (Aridic Haplustalfs) and La Casa-Aspermont (Typic Paleustolls) soils before 1994. Negative PMN required a high level of fertility management to improve stand productivity. Shift from OWB to wheat increased soil PMC and PMN in the short-term. No-till and CT treatments had PMC averaging 8.9 and 9.6 g m−3 d−1 or 23 to 32% higher than those from OWB treatments in the 0- to 0.3-m depth of Dalhart soil. Soil PMC of the CT treatment averaged 7.2 g m−3 d−1 or 73% higher than that of the La Casa-Aspermont under OWB. The trend of higher mineralizable C and N suggested that post-CRP conservation practices, in particular NT, contributed to HEL restoration by also controlling the upward movement and loss of CO3-C, maintaining these lands as C sinks in semiarid regions.

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

Copyright © 2002. American Society of AgronomyPublished in Agron. J.94:146–152.