Sodium nitrate is one of the oldest fertilizers (with the excemption of animal manure). It is highly soluble and perfect for leafy crops and in key times during plant growth. Use this fertilizer when your plants (notably for corn) are between their 4-7th leaf. The specialty salt can also increase the electrical conducitvity of your plants, giving them more energy. Use this for plants that require intense amounts of nitrogen (corn). Regular application of this fertilizer can greatly benefit your yields. ref: , .