Although ancient farmers did not know this hydrology, they did know that adding fish and seaweed to their fields caused plants to flourish. Not until the latter half of the past century did we begin to understand that it was the influx of minerals concentrated in the tissues of marine plants and animals that gave vegetables such a boost. Indeed, even now, we have only reached the cusp of which supplements from the ocean can benefit our farms and how they work in conjunction with soil biology.
Current thinking is that sea minerals allow soil bacteria and fungi to flourish and make use of organic matter in the formation of hummus. The resulting soil is rich in plant nutrients, and the vegetables grown in the soil are, in turn, healthier for us to consume.
Unfortunately, the science behind this ancient tradition of soil augmentation with fish and seaweed came after another, more arrogant discovery in agriculture: the development of NPK fertilizers. These letters stand for Nitrogen, Phosphorus, and Potassium, which were once believed to be the only soil components necessary for plants to thrive.
Scientists discovered that, indeed, the right ratio of these elements alone would allow plants to grow to gargantuan proportions. But it was only after millions of dollars of industrialization had solidified the chemical fertilizer market that the nutritive value of these vegetables was examined. The outcome was bleak. Foods grown in fields enhanced exclusively with petrochemicals are far less beneficial to humans than their naturally-grown counterparts.
Nonetheless, the cheapness of industrial crops makes them a juggernaut in the American food system. The cost of these artificially enhanced vegetables is not only to our health, but also, interestingly, to that of the sea. Industrial agriculture is inherently sloppy, and as millions of gallons of chemical fertilizers run-off into the sea, they create blooms of red tide and hypoxic zones where nothing can live for hundreds of miles.
Thankfully, small-scale farming and self-sufficient gardening are on the rise, and with them, a revival of old traditions—now backed with scientific research. There are even fancy new products that the organic grower can buy such as powders harvested from ancient sea beds and emulsions of liquefied fish, and I am sure that they are very effective. But for the self-sufficient gardener trying to stretch every penny, I believe that sticking with tradition is just as fruitful—adding self-caught fish and freshly-gathered seaweed to the soil.
Harvesting & Spreading Seaweed
Autumn is an excellent time to amend the soil, not only because most of the crops have been harvested, but also because the ocean is still warm enough to wade in when collecting your natural marine additives. At this point, I don’t have the time or resources to catch fish enough fish to add to the soil, but picking seaweed is quick and all you need is a bucket:
- First, till your field or garden after the pumpkins have been taken from the fields and the corn stalks are nothing but brown ghosts of themselves.
- Next, drive down to the ocean. Look for rocky shores, as these are most likely to contain seaweed beds.
- Wade into the water, grab a handful, and tug. Take more than you think you need, because spreading the seaweed over a large garden bed doesn’t cover as much as you might think. You can also add the stuff from the beach, but it doesn’t contain nearly as many nutrients as the fresh stuff.
- Once you’ve collected your seaweed, spread it evenly over your beds or field. Some books recommend rinsing it off first with fresh water, but I find this unnecessary unless you were dumping a foot worth of seaweed over your entire field.
- Finally, till the soil to incorporate all of the goodness you just worked so hard to harvest and spread. A pitchfork will do well, but if you are pressed for time and must use a gas tiller, beware your seaweed getting clumped up around the spokes.
Please Note:There may be laws in your area about taking fresh seaweed, so be mindful. In my opinion, so long as you are not stripping the place clean, the cause is more than justified, and it is a renewable resource.