We need to understand carbon balances for agri- production, land management and so that practical working limits for what we term carbon sequestration can be met, developing a robust methodology for this has led to understanding assessment of carbon sink relationships with water use, biodiversity and other ecosystem services. A limit for dynamic fixation of carbon by crops must be photosynthetic carbon fixation, this carbon can be lost or utilised by metabolism, respiration and structural development which in the case of something like grass, 70% of biomass is water. That brings us to water, the amount of water required for biomass production is metabolically limited and therefore we use this to calculate how much water is needed to be transpired for a given yield. All of this is of growing importance with our UK dry summers and wet springs- planning ahead in such uncertian patterns is an essential part of reducing commercial risk.
Grassland enterprises are where production strategy can change in an instant because of 10 mm of rainfall. You need to be risk-readied, and data makes that possible if you are asking the right questions and looking at it in the right way. The first thing to mention is the scale of water use and residual carbon, is that it screams at us, ‘where does that water come from, is it sufficient and where does that residual carbon go, can it be used’. Also, ‘what happens if residual carbon decreases and is that inescapable for some cropping?’
The concepts are borne from our interest in the first ecosystem paper we saw way back in 1997 from Costanza et al, in that Nature paper we saw how things could be calculated and considered within an economic framwork. Even further back are the agronomic constants on which we stand on the shoulders of others- some of them bigger and more useful than others! What’s more, the really bright science is stacking up as well, see https://www.nature.com/articles/s41561-026-02103-0, we just want to apply it and grass is a good start.
