Matthew Gardner

How does Chicory affect the nitrogen cycling of pasture systems?

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Growers in the medium and high rainfall zones of southern Australia have few alternatives when it comes to high quality summer forages apart from lucerne. Recently, chicory (Cichorium intybus) has been identified as a new perennial forage species that is more tolerant to acidic and waterlogged soils than lucerne.

Chicory is a short term perennial herb which has a high nitrogen (N) requirement. Its responsiveness and recovery of applied N is extremely efficient in comparison to other pasture and crop species currently used in mixed farming systems. In addition to high N recoveries chicory also has high mineral contents, low levels of structural carbohydrates, large taproot systems and active summer growth habits. These properties are hypothesised to significantly affect the processes within the N cycle. In particular, it is expected that mineralisation, immobilisation, plant uptake of inorganic N and biological N fixation would be effected under a chicory-legume pasture mix. These key processes of the N cycle can either reduce or promote the supply of N to pastures and subsequent cropping phases.

Therefore, Matthew has two key objectives for his research. Firstly, to quantify the effect that chicory has on N turnover under a chicory-legume pasture mix. Secondly, to determine the mechanisms responsible for any changes within the N cycle under this pasture mix. Based on the findings best practice N management can be determined for chicory pasture mixes to improve their productivity in mixed farming systems.

Matthew’s research falls into the CRC’s Program 2 research area.

Objectives:

• Determine the influence that chicory has on N turnover under a chicory-legume pasture mix
• Determine the mechanisms responsible for any changes within the N cycle under this pasture mix
• Develop some best practice nitrogen management guidelines for chicory/legume pasture mixes.

For more information, email Matthew.