How to Make Nitrogen Fertilizer. Use compost. Add in some composted coffee grounds. Try composted manure. Mix in a good dose of blood meal for a quick-release fertilizer. Apply cotton seed meal cautiously. Use crab meal, feather meal, or leather meal for slow-release fertilizers. Try biosolids and wood. Plant nitrogen– … A good organic nitrogen fertilizer should be added to the soil whenever you plant heavy-feedingvegetables like tomatoes, peppers, chiles, eggplants, … 10 Best High Nitrogen Natural Fertilizers for your organic garden; choose wisely from some of these options. Nitrogen-Rich Blends. If your plants prefer a complete fertilizer with a higher percentage of nitrogen, manure is an easy option that provides the 3 main nutrients — namely, nitrogen, phosphorus and potassium — with nitrogen being the biggest dose. Manure also improves soil structure and adds micronutrients.