To illustrate what I�m saying�..Here is my first crop of summer weeds today. Its now part of an organic nutrient reserve in the top 5-6 inches of soil (the black dirt you see). That bank vault is capable of holding onto exponentially more nutrients and water than what our sand is capable of. This is what gives us rich fertile soil instead of sand. A soil test is going to show you what your soil nutrient vault is lacking or what you need to do to get it in balance.