Climate change and nutrient dynamics

Impact of elevated CO2 on crop growth and soil nutrient dynamics

Using 13CO2 pulse labelling to study carbon allocation in the soil-plant system under elevated CO<sub>2</sub>. SoilFACE facility, Department of Primary Industries, Horsham.Climate change is expected to have a major impact on the Australian grains industry. Although increases in atmospheric CO2 are predicted to initially increase plant productivity, achieving these productivity benefits is expected to be limited by water and/or nutrient deficiencies.

Australian grain production systems are characterised by low rainfall and infertile soils and there is considerable uncertainty about the applicability of overseas data to predict how these systems will respond to elevated CO2.

This project utilises the Soil Free Air CO2 Enrichment (SoilFACE) array and stable isotope techniques to examine how the interactions between elevated CO2, water supply and soil physiochemical properties affect above- and below-ground biomass distribution, N fixation and litter quality (C:N:P), and the processes regulating the subsequent cycling of C, N and P in a cereal-legume rotation.

Studying the effect of elevated CO<sub>2</sub> on below-ground processes at the SoilFACE facility, Department of Primary Industries, Horsham.

We have shown that elevated CO2 increased P and N uptake and nodule number in legumes, which resulted from the increased biomass production. Elevated CO2 appears to enhance P immobilisation in the rhizosphere.

The project aims to fill significant knowledge gaps that currently limit the reliability of process-based models to accurately predict the impact of future climates on the productivity and sustainability of Australian grain systems.

Contributors: Dr Clayton Butterly, Jian Jin, Associate Professor Peter Sale and Caixan Tang.

Collaborators: Professor Roger Armstrong and Dr Nicole Mathers (DPI Victoria). Professor Deli Chen (Melbourne University), Professors Shaojian Zheng and Yongsong Zhang (Zhejiang University).

Funded project:

  • Below-ground processes: Filling the missing gap in predicting the response of grain production to elevated CO2 in southern Australia (Funded by ARC)

Impact of warming on soil nutrient and vegetation dynamics

Using ion-exchange membranes to study the impact of warming on plant nutrient uptake and soil nutrient dynamics.Rising global temperatures are already impacting on Victorian Alpine ecosystems. Our research aims to detect and evaluate the consequences to soil nutrient dynamics and vegetation ecology in the Bogong High Plains, Victoria.

Current projects examine:

  1. the interactive effects of experimental warming and bushfire on soil nutrient dynamics
  2. the effect of warming on nutrient release from decomposing plant litter
  3. the impact of elevated nutrient level on plant community dynamics.

Open top chambers to study the effect of warming on nutrient dynamics using litter bags.Contributors: Dr Alison Monsant, Dr Gary Clark, Gaëlle Ng Kam Chuen, Dr Carl-Henrik Wahren, Warwick Papst, Professor Caixian Tang.

Collaborators: Professor Ary Hoffmann (Melbourne University), Dr Dick Williams (CSIRO Sustainable Ecosystems), Dr Ian Mansergh (DSE Victoria).

Funded project:

An integrated assessment of the impacts of climate change on Victorian alpine ecosystems: Detecting and managing ecological change (ARC).

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