University of Tasmania
Browse

File(s) not publicly available

Nitrogen contributions in a windmill grass (Chloris truncata)- wheat (Triticum aestivum L.) system in south-western Australia

journal contribution
posted on 2023-05-16, 20:39 authored by Syme, H, Tina AcunaTina Acuna, Abrecht, DL, Wade, LJ
Chloris truncata, a perennial grass that is native to Australia, has potential as a short-lived summer pasture in rotation with wheat and other winter crops in the low to medium rainfall zone of south-western Australia. In this paper we examine the nitrogen contributions from a C. truncata-wheat system, with the expectation that C. truncata may take up nitrate which would otherwise be lost to leaching, for later release to the following wheat crop. In glasshouse experiments, residual soil nitrate in bare soil was available for uptake and growth of wheat, with a greater response when N was applied. In contrast, wheat grown on C. truncata stubble was mostly reliant on recently mineralised nitrogen, as the previous rotation had depleted the soil of nitrate. Shoot stubble of C. truncata provided sufficient mineralised nitrogen such that the uptake of nitrogen and biomass of wheat equalled those from bare soil. Wheat grown on root stubble of C. truncata had half the biomass production of that grown on either bare soil or shoot stubble, with root + shoot stubble intermediate. In a field trial undertaken at Bruce Rock in Western Australia, nitrogen release from C. truncata stubble at low to intermediate stubble densities increased tiller production, nitrogen uptake, and growth of wheat, but not at the highest N rate in this season, which received below-average rainfall in July. These results provide initial evidence concerning how a C. truncata-wheat system could improve the N balance of the farming system, by potentially reducing the leaching loss of nitrate in autumn, and then releasing mineralised N from stubble when needed by a following wheat crop. While these results require further confirmation, especially in the field, they raise exciting prospects for an improved agronomic system, with potential benefits to N balance, carrying capacity, yield stability, and groundwater discharge. The system requires further study to quantify these processes, and explore their implications. © CSIRO 2007.

History

Publication title

Australian Journal of Soil Research

Volume

45

Issue

8

Pagination

635-642

ISSN

0004-9573

Department/School

Tasmanian Institute of Agriculture (TIA)

Publisher

CSIRO Publishing

Place of publication

Australia

Repository Status

  • Restricted

Socio-economic Objectives

Wheat

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC