Alfalfa pellets work great to fertilize cole crops – broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale and kohlrabi.
Many folks use alfalfa rabbit food to fertilize their gardens. The pellets are smaller and will break down quickly (but not much faster than the larger version). If you have access to free alfalfa rabbit food, try to find out what’s in it first. Look at all the ingredients in this bag from my local feed store – flour, oil, preservatives, iron, salt and supplements…not ideal.
I use horse feed (pure alfalfa) and sprinkle about a cup on top of moist soil for every 3′ x 3′ area – supplies nitrogen, potassium, trace minerals and growth stimulants in the early stages of growth. It’s also an awesome compost accelerator and soil amendment (work it in a month before planting).
Recycle Old Potting Soil
I’ve experimented with this idea in potting soil too at home and school (inherited a lot of dead, synthetically enhanced stuff early 2013). I dump it all in a huge tub, remove old roots and debris mix in some alfalfa and wait a month before using again. Even better is to add in some compost and kelp leaves along with the alfalfa. That’s my method anyway.