Caro with the penetrometer in the bare soil plots
We had a visit this week from former crew member Caro Rozell, who is now the Education Director for NOFA/Mass and a budding soil scientist extraordinaire. She was out to consult with us on our process for transitioning some plots over to no-till production, which would potentially supercharge our carbon sequestration and soil productivity both. We have two different plots that we were looking to transition to no-till. One was put into an oats cover crop last fall, and then spread with a thick layer of compost and then covered with a tarp last winter. The other was left bare and covered with a tarp until last week (you guessed it, we took the tarp off the second section and moved it to the first!) The bare, tarped treatment looked a little hard and packed to plant into, so we wanted Caro to give us a little advice. The difference in the soil structure in the two plots was really remarkable. Caro took readings with the penetrometer, which measures the force it takes to poke something into the soil, and also did an infiltration test, that measures how fast water sinks into the soil. The cover-cropped section sucked up the same amount of water in 8 seconds that the bare soil section took 34 seconds to absorb! Here are side-by-side pictures of a shovelful of soil from the two plots.
Shovelful of soil from the cover cropped plot showing nice structure that crumbles into smaller aggregates.
Shovelful of soil from the bare-ground plot; note how it is just one big hard block.
We knew in theory how effective cover cropping is on building up soil fertility, and have certainly seen how our soil management has improved our productivity over the years, but it was really rewarding to see it demonstrated so clearly in a side-by-side plot! The good news: Our transition to no-till production will hopefully move our gains in soil quality enough that the cover cropped soil above will look shabby by comparison!
