I’ve really been bowled over this year at just how much the pastures at Potter Hill have improved over the last 4 years. Four years ago, the fields were full of weeds, and maybe if you looked close you could find a sprig of clover or a tuft of decent grass. The lower, wetter fields were especially bad, providing very little grazing value for the animals. However, even those fields that were the poorest pasture are now full of three species of clover and and show signs of the best grasses (timothy and orchard grass) moving in.
I’m not sure if there’s anything in the scientific literature about increasing productivity in old fields through grazing and management, but here’s my theory, at least as applies to the specific situation at Potter Hill. In our soils, there is a natural glacially-deposited layer of barely permeable material just under the topsoil. This means that when it rains, the water flows downhill through the top layer of soil, carrying nitrogen with it to the bottom of the hill. The resulting nitrogen-deficient soil is actually the perfect environment for clovers and other legumes – these plants fix their own nitrogen from the air with the help of soil microbes. This is a competitive advantage for them, and I have noticed that any bare patch at Potter Hill (e.g. cow hoof print in the mud, pig rootings) tends to come up clover. After a few years of grazing and mowing, the clover and vetch (another legume) have gained a foothold throughout the fields. And now, especially since we do not make hay and export any of those nutrients from the farm, these legumes are enriching the soil with the nitrogen they produce. Once there is enough nitrogen in the soil, the grasses (which do not fix their own nitrogen) can take off.
Don’t get me wrong, there’s still work to do and room for improvement. But the change really has been dramatic.
In other news, plenty of greens to go around this week. And radishes, too. (Sorry, jumped the gun on the radishes – hopefully next week!)
Coming soon (but not toooooo soon): chard, squash, zukes, beets, carrots.