Soil organic carbon and total nitrogen under Leucaena leucocephala pastures in Queensland

Radrizzani, Alejandro, Shelton, H. Max, Dalzell, Scott A. and Kirchhof, Gunnar (2011) Soil organic carbon and total nitrogen under Leucaena leucocephala pastures in Queensland. Crop and Pasture Science, 62 4: 337-345. doi:10.1071/CP10115


Author Radrizzani, Alejandro
Shelton, H. Max
Dalzell, Scott A.
Kirchhof, Gunnar
Title Soil organic carbon and total nitrogen under Leucaena leucocephala pastures in Queensland
Formatted title
Soil organic carbon and total nitrogen under Leucaena leucocephala pastures in Queensland
Journal name Crop and Pasture Science   Check publisher's open access policy
ISSN 1836-0947
1836-5795
Publication date 2011
Sub-type Article (original research)
DOI 10.1071/CP10115
Open Access Status
Volume 62
Issue 4
Start page 337
End page 345
Total pages 9
Place of publication Collingwood, VIC, Australia
Publisher C S I R O
Subject 1102 Cardiovascular Medicine and Haematology
1110 Nursing
Abstract Soil organic carbon (OC) and total nitrogen (TN) accumulation in the top 00.15m of leucaenagrass pastures were compared with native pastures and with continuously cropped land. OC and TN levels were highest under long-term leucaenagrass pasture (P0.05). For leucaenagrass pastures that had been established for 20, 31, and 38 years, OC accumulated at rates that exceeded those of the adjacent native grass pasture by 267, 140, and 79kg/ha.year, respectively, while TN accumulated at rates that exceeded those of the native grass pastures by 16.7, 10.8, and 14.0kg/ha.year, respectively. At a site where 14-year-old leucaenagrass pasture was adjacent to continuously cropped land, there were benefits in OC accumulation of 762kg/ha.year and in TN accumulation of 61.9kg/ha.year associated with the establishment of leucaenagrass pastures. Similar C:N ratios (range 12.714.5) of soil OC in leucaena and grass-only pastures indicated that plant-available N limited soil OC accumulation in pure grass swards. Higher OC accumulation occurred near leucaena hedgerows than in the middle of the inter-row in most leucaenagrass pastures. Rates of C sequestration were compared with simple models of greenhouse gas (GHG) emissions from the grazed pastures. The amount of carbon dioxide equivalent (CO 2-e) accumulated in additional topsoil OC of leucaenagrass pastures ≤20 years old offset estimates of the amount of CO2-e emitted in methane and nitrous oxide from beef cattle grazing these pastures, thus giving positive GHG balances. Less productive, aging leucaena pastures 20 years old had negative GHG balances; lower additional topsoil OC accumulation rates compared with native grass pastures failed to offset animal emissions.
Keyword Carbon balance
Carbon sequestration
Greenhouse gas balance
Permanent pastures
Soil organic carbon
Soil total nitrogen
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Agriculture and Food Sciences
 
Versions
Version Filter Type
Citation counts: Scopus Citation Count Cited 5 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 27 Nov 2013, 19:40:51 EST by System User on behalf of School of Agriculture and Food Sciences