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.
Dr David Whitehead, Manaaki Whenua - Landcare Research (2010-present) Professor Frank Kelliher, AgResearch (2010-2017)
The carbon balance of temperate grasslands part II: The impact of pasture renewal via direct drilling
S. Rutledge, A.M. Wall, P.L. Mudge, B. Troughton, D.I. Campbell, J. Pronger, C. Joshi, L.A. Schipper, The carbon balance of temperate grasslands part II: The impact of pasture renewal via direct drilling, Agriculture, Ecosystems & Environment, Volume 239, 2017, Pages 132-142, ISSN 0167-8809, http://dx.doi.org/10.1016/j.agee.2017.01.013
Two blocks had pastures renewed (PR) by direct drill. A third block was a control.
The PR blocks had smaller positive NEPs than the control block during the PR year.
Duration of fallow is important in determining total CO2 losses due to PR
Pasture renewal led to a negative carbon balance (soil C loss) for the PR year
Addition of C (e.g. manure, effluent, feed) helps to mitigate soil C loss due to PR.