Soil Carbon

Increasing the quantity of carbon stored in agricultural soils has the potential to offset emissions of greenhouse gases to the atmosphere, while soil carbon losses would further add to those emissions.

However, realising this mitigation potential is technically challenging when soil carbon stocks are already high (as they are in New Zealand), potential changes in soil carbon are small and spatial variability is high.

The current NZAGRC programme has three distinct components:

(1) testing specific management practices that may increase the long term soil carbon store in field situations;

(2) developing and using models to predict how a range of management practices may influence long and short tem soil carbon storage; and

(3) identifying those factors that influence the stability of current or newly added soil carbon.

We have also supported international work to map on farm soil carbon and will participate in the international research programme CIRCASA.

Principal Investigators

Dr David Whitehead, Manaaki Whenua - Landcare Research (2010-present)
Professor Frank Kelliher, AgResearch (2010-2017)

Research Stories

Soil and pasture research that is sweet enough to eat

Scientific knowledge is usually communicated through text, diagrams and graphs, but the Waikato Biogeochemistry and Ecohydrology Research group (WaiBER) offers an alternative means of communication - via the medium of cake.

Once a paper is accepted, group members are encouraged to make a research cake that summarises the paper to enjoy and celebrate with their colleagues.

The NZAGRC is proud to have played a part in the generation of two recent, clever and edible research cakes (and the papers that inspired them).

The first of these cakes was prepared by Sam McNally (PhD candidate supported by NZAGRC) on acceptance of his first research paper in the journal Plant and Soil. Sam is supervised by Professor Louis Schipper at the University of Waikato.

Sam's paper compared root biomass of ryegrass/clover and more diverse pastures (including plantain, chicory, and lucerne) over the seasons of a year. He found greater root biomass in the more diverse pastures, which also had deeper rooting. The hypothesis is then posed that this greater biomass will increase carbon inputs and potentially storage in soil.

On Sam's cake, the diverse pasture is on the left and you can see greater rooting depth and biomass down the side. Lego man is taking cores on either side of the wooden fence.

McNally, S.R.; Laughlin, D.C.; Rutledge, S.; Dodd, M.B.; Six, J.; Schipper, L.A, 2015. Root carbon inputs under moderately diverse sward and conventional ryegrass-clover pasture: implications for soil carbon sequestration. Plant and Soil.

The second cake was produced by Dr Susanna Rutledge to celebrate the publication of a paper in Agriculture, Ecosystems and Environment that looked at the carbon balance of a dairy grazed pasture at Scott Farm over four years. This project receives funding from the NZAGRC.

Depicted on the colourful cake is the average carbon inputs and outputs in units of jellybeans (jb), where 1 jb = 200 kgC/ha.y. Inputs (left side) include imported feed, effluent and the net of carbon dioxide exchange. Outputs include milk export, silage and methane. The balance (3 jelly beans) is assumed stored in soil.

S. Rutledge, P.L. Mudge, D.I. Campbell, S.L. Woodward, J.P. Goodrich, A. M. Wall, M.U.F. Kirschbaum, L.A. Schipper, 2015. Carbon balance of an intensively grazed temperate dairy pasture over four years. Agriculture, Ecosystems and Environment, 206, 10-20 

Research cakes are a novel way to portray - and celebrate - research done within the WaiBER group.

Check out the other mouth-watering and thought-provoking cakes at

If your work under the NZAGRC-PGgRc science programme is celebrated in an interesting way - or if your work has produced some really great results recently - let us know for a future newsletter story




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