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Agricultural consultant John Geraghty was the first speaker at Thursday’s Irish Grassland Association Beef Conference, where he gave a presentation on soil health.
Geraghty explained that: “Wherever you go in the world, to be a good farmer you need to be good at three things; photosynthesis, the carbon cycle and the water cycle.”
He added that “what people don’t think about is that all these three things are completely free".
In terms of photosynthesis he explained that it is “the main driver of plant growth. Dawn was at 5am this morning, so photosynthesis started while we were all still in bed. Photosynthesis drives root growth which in turn drives the mineral cycle. The way we harness photosynthesis is through plant and leaf structure".
Grazing
Geraghty advised that grazing intensity and soil damage or compaction play huge roles here.
“If we graze too tightly, we can actually shut down grass recovery. It’s the same with mowing. The less leaf exposure we have, less photosynthesis is taking place.”
The only way to improve soil structure is through plants and animals
In terms of compaction, he said: “We really need to consider machinery and the impact tyre size and pressure can have on compaction which in turn leads to root and water permeability issues.”
On subsoilers, he said they are pretty much “a waste of time”.
“There is a saying that you don’t build soil with steel. The only way to improve soil structure is through plants and animals.”
Soil
Soil structure and texture is a major contributing factor to grass growth. “If you don’t do a soil texture analysis of your farm, you are essentially farming with your hands tied behind your back.”
One final area that Geraghty highlighted was soil carbon. Soil carbon is the cap stone of soil fertility - if we don’t build carbon in the soil we will never get soil nutrients to the optimum levels.” The primary source of carbon in soil is organic matter.
For more on the Irish Grassland Association Beef Conference, stay tuned to the Irish Farmers Journal online this weekend and see next Thursday’s paper.
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