Practical facts that provide understanding

Did you know that if we compressed the atmosphere and turned it into liquid, then the oceans would be 500 times bigger? This reminds us that we perceive things the way we think.

What actually happens in the paddock can at times be very different to our perceptions. Take the case of root growth with grasses. When livestock over consume the leaves of grasses, while they are trying to grow after rain, some would assume that this is just reducing potential ground cover. Even amongst those who are aware that there is a relationship between root growth and grazing pressure, they still may not be aware that there is a tipping point after which leaf removal can suddenly have really adverse outcomes for root growth.

The effect leaf removal has on root growth

It is so easy for us to forget that plants make decisions just like we do. It is now well known that plants send out chemical instructions to activate soil microbes to get them to do what they need done. The graph above highlights that plants also make decisions around allocation of incoming carbon (remembering that roots are 45% carbon). Plants are not stupid, so we have to assume that they do understand the importance of roots, however when leaves start to be excessively over eaten by animals, they place a higher priority on replacing leaves. This is logical as leaves are the entry point of carbon and energy.

The water holding capacity of organic matter

There is no substitute for going back to the basics to get things into perspective. When running a grazing business, there is a price to be paid for not letting plants generate carbon flows to their full potential.  Thinking about the carbon that ends up in the soil, a 1% increase in soil organic carbon means the soil can hold an extra 144,000 litres per ha (2.5 acres). Organic matter can hold 5 times its weight in water.

The energy in organic matter

Just as modern society is reliant on energy, the health of paddocks and their productive capacity are driven by available energy. It is carbon that carries energy. Sheep and cattle rely on the stored energy in grass and, soil life also relies on the energy brought in by plants. Researchers in England discovered that an acre (0.4 ha) of soil with 4% organic matter contains as much theoretical combustible energy as 20-25 tonnes of anthracite coal. Another researcher in Maine, US, equated the energy in that amount of organic matter to 4,000 gallons of fuel oil.


We have all heard the saying, “Perceptions are stronger than the truth”. However, with land management, facts are better than perceptions.

Having understanding is the basis of good management.

Next week’s discussion:   “Where carbon resides”