As you think about how you’ll manage forage this season, keep in mind that your grazing management has a lot to do with how your soil captures and holds water – its hydrologic functioning. That function is crucial to determining how well your soil will provide water during dry periods, as well as how well it recovers during wet periods.
It’s more important than ever to have pastures that are really good at capturing rainfall, because, increasingly, more rainfall is coming in single rainfall events. In 2016, 20% of all rainfall occurred in single day rainfall events. When all that rain comes down at once, it can get lost, taking topsoil away with it. Or, if conditions are right, it can get captured, and maybe even be available as moisture your forage can rely on in dry periods.
Managing your grazing to avoid overgrazing will go a long way to strengthen how your pasture captures and holds rainfall. Overgrazing means that you’re like to have bare spots between plants and those bare spots lead to runoff and erosion. The runoff is a loss of moisture your soil could be holding for when you might be needing it. The erosion is a loss of the topsoil you’ve worked hard to build. On the other hand, if the forage left in your pasture covers the ground well, it means that rainfall has a chance to soak into the soil, rather than run off.
You can see this concept in action in this 3:42 minute video. J.D. Daniel of Virginia compares pasture runoff and infiltration on overgrazed vs. managed pasture. The water that infiltrates is water you can count on down the road. The water that runs off is water that pretty much has gone down the road, taking your valuable soil with it. J.D. has some great observations about how plant canopy and residues protect the soil and allow rain to infiltrate. Enjoy!
The sobering part is that overgrazed pasture infiltrates similar to conventionally tilled ground-very poorly. As graziers, we have the potential to capture more rainfall through managed grazing than any other agricultural system.
Thank you, Rachel, for the demonstration.
Sooo very important. Thank you for the reminder!
You are so welcome! I think it’s such a striking comparison between the runoff and infiltration in the jugs from overgrazing and managed grazing – at 2:08 and 2:22.
Thanks for all you do!