By the book, “Repurposing” is the use of a tool being re-channeled into being another tool, usually for a purpose unintended by the original tool-maker. One of the most common repurposed tools is the screwdriver. Most everyone will tell you it’s not a pry bar! I have a friend of mine that is a “master repurposer’”. Chuck is a container gardener and inventor of the garden in a boat. It’s not a big garden because it isn’t a big boat, but it came with its own drain plug. From turning an old pair of blue jeans into a rifle case to his plans of making a dune buggy out of an early 70’s Cadillac Eldorado; Chuck has a vision for everything! For us all-natural mined gardening folks the same philosophies should apply. I used a broken hoe handle as a row marker in the garden for years until it rotted away. I have used the fishing line as a trellis and what some people are doing with pallets is quite innovative.
I hope you have looked (and read) the labels of the products that you use. Almost all of the all-natural/organic fertilizers are using the same ingredients for phosphate (2nd number) and potash (3rd number). Nitrogen (1st number) is where you get a multitude of different ingredients. Manure (chicken & cattle) based nitrogen is very common along with meal products such as cottonseed, soybean, and alfalfa. Some manufacturers will also use feather meal. Way back in the 1970s and into the 80’s you could buy both feather and fish meal in bags. Not anymore.
Stay with me now; in the world of livestock feed, cottonseed meal and soybean meal are for cattle, with alfalfa pellets feeding both horses and cattle. You can convert food-based protein into nitrogen here.
Soybean meal is at 48% protein = 7.68% nitrogen. Cottonseed meal is a 41% protein = 6.56% nitrogen. Alfalfa pellets are a 17% protein = 2.72% nitrogen. The average price of a bag of all-natural/organic fertilizer is in the $28.00 range. A bag of soybean meal is the $15.00 range.
So here is the question: Can you use livestock feed as a replacement for fertilizer? The short answer is, sometimes. If all you are looking for is nitrogen, give it a try. In my experience, St. Augustine grass responds better than Bermuda to repurposed livestock feed.