You can add coffee grounds directly to the soil by mixing damp grounds into the soil or by spreading the grounds over the surface of the soil and covering them with organic mulch.
Note that there are downsides to using animal manure. Manure tends to increase the salt content of soil, and using manure may lead to an increased yield of weeds.
Blood meal is an especially good source of nitrogen for heavy feeders, like lettuce and corn, because of how fast-acting it is. Blood meal can also be used as a component in compost or as an accelerant for other organic materials, since it promotes the decomposition process.
The major disadvantage of cotton seed meal is that it has a negative impact on soil pH. It greatly acidifies soil, so if you plan to make an organic fertilizer out of cotton seed meal, you should also carefully monitor the pH of your soil.
Just toss some legumes on the soil. Mung beans are suggested since they don’t grow too big but they grow fast. To replenish Nitrogen on the soil. Try fallowing. When resting your plot on the 7th year, sow some mung beans. Don’t harvest the mung beans, instead, let the seeds fall into the ground for more nitrogen-fixers. Do this, especially if you will be planting heavy feeders like corn on the next growing year.
