Surprisingly, very few local businesses sell organic fertilizers with a balanced mixture of each. Last year we just thought if we poured on a little chicken poop, everything would be great and it would all grow perfectly. That really wasn't the case because if the nutrients plants need are not in the soil and not in the manure, they just won't produce.
Our tomatoes grew really tall last year, but didn't produce as much fruit as we were hoping for. Too much vine and not enough fruit. This was because we used too much nitrogen and not enough potassium and phosphorus. This year we will not make the same mistake. We want to make sure we get a balanced mixture.
That is why we had our soil tested by our local county extension office. They do this for a small fee. It is easy to do -- just gather some dirt a specified number of times from all around your garden, mix it in a bucket and take out the required amount of dirt, place it in a baggie and take it in. (They have the instructions.)
They will send you detailed results so you will know what you need to add for your soil to be at its best. We were told to use 10-10-10 fertilizer. Since we don't use non-organic fertilizer, we set out to buy some organic fertilizer with those numbers, but we couldn't find it anywhere we shopped. We did what we had to do to make our fertilizer approximate those numbers.
This year we are trying to do an even better job with our mixture. We started out with chicken manure for consistency and to amend the soil, then added the prepared organic fertilizers that best add up to 10-10-10, keeping in mind that only 10 percent of the fertilizer in the bag contains the nutrients we need and 90 percent is a filler. We used cottonseed meal or blood meal for the nitrogen, bone meal for the phosphorus, and potash for the potassium. Here is where we get in over our heads. Some of these mixtures are not purely N P or K. Some include mixtures of two or all three. We have to approximate what we use and add portions of each in the amount we "think" will equal kind of--sort of what we need.
I know one day, someone will come up with an organic mixture for people like us who are still scratching their heads over how to mix up a batch of fertilizer, but until then, we will start with a wheelbarrow, pour in the manure and then add things until we think we have a good enough mixture. Our plants will show us if we are right.