Water use, root activity and deep drainage within a perennial legume-grass pasture: A case study in southern inland Queensland, Australia

Pachas, A. Nahuel A., Shelton, H. Max, Lambrides, Christopher J., Dalzell, Scott A., MacFarlane, David C. and Murtagh, John (2016) Water use, root activity and deep drainage within a perennial legume-grass pasture: A case study in southern inland Queensland, Australia. Tropical Grasslands - Forrajes Tropicales, 4 3: 129-138. doi:10.17138/TGFT(4)129-138


Author Pachas, A. Nahuel A.
Shelton, H. Max
Lambrides, Christopher J.
Dalzell, Scott A.
MacFarlane, David C.
Murtagh, John
Title Water use, root activity and deep drainage within a perennial legume-grass pasture: A case study in southern inland Queensland, Australia
Journal name Tropical Grasslands - Forrajes Tropicales   Check publisher's open access policy
ISSN 2346-3775
Publication date 2016-09-05
Sub-type Article (original research)
DOI 10.17138/TGFT(4)129-138
Open Access Status DOI
Volume 4
Issue 3
Start page 129
End page 138
Total pages 10
Place of publication Valle Del Cauca, Colombia
Publisher Centro Internacional de Agricultura Tropica
Collection year 2017
Language eng
Formatted abstract
Water use and depth of water extraction of leucaena (Leucaena leucocephala) and Rhodes grass (Chloris gayana)
pasture, irrigated with desalinated coal seam water (a by-product of the coal seam gas industry), were monitored to
provide background information on root activity, spatial and temporal water use and deep drainage over a 757-day period
from August 2011 to August 2013. Methodology comprised measurement of soil water from surface to 4 m depth using
8 EnviroSCAN probes connected to dataloggers positioned within leucaena twin rows and within the Rhodes grass interrow.
Just over 581,000 individual moisture measurements were collated and are reported here. Water extraction (and by
inference root activity) of leucaena and Rhodes grass showed marked seasonal fluctuation with deepest and highest water
extraction occurring during the first growing season; water extraction was greatly diminished during the following drier
and cooler seasons due to the negative influences of lower soil moisture contents, lower temperatures and increased
defoliation on pasture growth. The highest values of deep drainage below 4 m depth occurred when high rainfall events
corresponded with high soil water storage in the entire profile (0–4 m depth). Given that water usage by both leucaena
and Rhodes grass was greatest in the upper layers of soil (<1.5 m), future research should focus on how the level of
competitive interaction might be managed by choice of row spacing and frequency of irrigation. Further studies are
needed, including: (a) physical sampling to determine the depth of active roots; (b) how defoliation affects rooting
behaviors and water use of leucaena; and (c) modelling of the water and salt balances of leucaena and grass inter-row
systems using data from this study, with various levels of irrigation, to investigate the risks of deep drainage over an
extended climate sequence.
Keyword Active rooting depth
agroforestry
Chloris gayana
Leucaena leucocephala
water extraction
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Agriculture and Food Sciences
Centre for Nutrition and Food Sciences Publications
 
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Created: Fri, 21 Apr 2017, 13:34:05 EST by Anibal Nahuel Alejandro Pachas on behalf of Centre for Nutrition and Food Sciences