Raindrops
that hit bare earth break the soil into small mobile particles. These small particles get carried away in run-off and turn our rivers brown. Any nutrients in the topsoil goes along for the rid. Groundcover protects the soil from raindrop impact so the soil doesn't get washed away. Rivers and wetlands remain healthy and nutrients stay in the topsoil to feed crops and native vegetation.
For a demonstration of the importance of groundcover, watch this video taken at the Katherine Show where we use a soil erosion simulator to entertain the kids. Expert commentary from Fergal O'Gara!
This is all quite correct, but naive and anachronistic. It is a partial explanation of sediment loss and declining rain use effieciency. What also matters is what happens at the drainage ecosystem level. If this is falling apart, no grazing management will stop the dehydration
ReplyDeleteThanks for the comment. It is only part of the explanation. The post was only written in the context of the simulator which only simulates sheet erosion. Click on the topic "landscape rehabilitation" for a post about the drainage ecosystem.
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