In organic farming, the inputs used — for fertilizing crops, controlling disease or pests, etc. — have to meet USDA organic standards and be approved by the Organic Materials Review Institute (OMRI). No Roundup here, thanks, though there are extensive lists of what is allowed.
For building soil fertility, there are several methods an organic farmer can use. Sure, there are a host of commercial products that are OMRI-approved, but many organic farmers (like Dave) get back to the original idea of organic, nurturing the soil by keeping the farm cycle closed. Composted animal manure can be used (following stringent guidelines for human health), and cover crops return nitrogen and other vital nutrients to the soil.
Dave uses both of these methods, of course. But the latest step in replenishing the soil this season starts here: at the pond. The weedy mess of algae found on and just below the surface provides the farm with a good mid-season green manure.
Up until a few years ago, Dave treated the pond as most of his neighbors do: with that ubiquitous dye that reduces algal growth. But then he read about coastal cultures that added seaweed to the soil for fertilizer (shades of Squanto and the Pilgrims!) and decided to stop the pond treatment and use the algae like seaweed.
Once the big garlic bed was cleared and ready for a new mid-season crop, Dave spent an hour or two one evening scooping algae from the pond and dumping it in piles on the banks. The next morning, he drove the small tractor around so that we could load the piles onto the flat trailer and take them to the open plot.
We picked up armfuls of the algae and slapped clumps down onto the bare, lumpy soil. A patch here, a patch there — until we had the algae worked through most of the plot. Days later, Dave ran the tiller through the bed, distributing the algae more deeply into the soil and smoothing out the texture of the plot.
After much consideration, Dave decided that we would plant a second crop of cucumbers in this patch, so that work — laying plastic and drip lines, planting seedlings — is coming up soon.
And whether or not we’ll harvest more algae for more fields yet this season remains to be seen.