Mineralisation of chicory and lucerne residues under field conditions

Matthew Gardner, Jason Condon, Guangdi Li, Mark Conyers, Richard Hayes, Jeffrey McCormick, Brian Dear

Research output: Book chapter/Published conference paperConference paper

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Abstract

The incorporation of chicory into phased farming systems requires an understanding of N mineralisation of chicory residues and the supply of N to subsequent crops. A field experiment was conducted to determine the relative rates of N mineralisation from chicory, chicory/subclover and lucerne/subclover residues. Existing pastures were removed by spraying with herbicide in either spring or autumn and mineral N was measured at the time of spraying, and then 6 and 12 months later. Chicory/subclover had the greatest mineralisation rate during the first 6 months after spraying in either spring (0.54 kg mineral N/ha/day) or autumn (0.64 kg mineral N/ha/day), whilst lucerne/subclover had the lowest at 0.07 and 0.08 kg mineral N/ha/day for spring and autumn, respectively. However, 12 months after spraying, the mineralisation rate increased for lucerne/subclover, but began to slow for chicory and chicory/subclover. Compared to chicory alone, growing chicory with subclover significantly increased the release of mineral N by 28 and 47 kg N/ha, 6 and 12 months after pasture removal, respectively. The mass of N mineralised 12 months after pasture removal was similar for chicory/subclover (219 kg N/ha) and lucerne/subclover (234 kg N/ha). However, as high rates of mineralisation occurred for chicory treatments within the first 6 months after spraying, chicory-based pastures could potentially be sprayed out later (eg autumn) than lucerne pastures allowing more grazing time without the risk of N deficiency to the following crop. Therefore chicory/subclover pastures are well suited to phased farming systems, particularly where pasture phases are shorter, as the N benefit can be readily utilised by following crops.
Original languageEnglish
Title of host publication16th AAC
Subtitle of host publicationCapturing opportunities and overcoming obstacles in Australian agronomy
EditorsI. Yunusa
Place of PublicationAustralia
PublisherThe Regional Institute
Pages1-5
Number of pages5
Publication statusPublished - 2012
Event16th Australian Agronomy Conference - University of New England, Armidale, Australia
Duration: 14 Oct 201218 Oct 2012
Conference number: 16th
http://agronomyaustraliaproceedings.org/index.php/2012-conf-proc-homepage (Conference proceedings 2012 homepage)

Conference

Conference16th Australian Agronomy Conference
Abbreviated titleCapturing Opportunities and Overcoming Obstacles in Australian Agronomy
CountryAustralia
CityArmidale
Period14/10/1218/10/12
Internet address

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  • Cite this

    Gardner, M., Condon, J., Li, G., Conyers, M., Hayes, R., McCormick, J., & Dear, B. (2012). Mineralisation of chicory and lucerne residues under field conditions. In I. Yunusa (Ed.), 16th AAC: Capturing opportunities and overcoming obstacles in Australian agronomy (pp. 1-5). The Regional Institute.