As a nutritionist, I realize the relationship and similarities between healthy soil and a healthy rumen in ruminants, which deer are. The ideal pH in soil is 6.5 and that is also the ideal pH in a rumen. In the soil low pH is considered acidic. In the rumen it's called acidosis. In the soil we want a lot of organic matter to help keep the soil loose as well as reduce water and nutrient loss. In a ruminant we also want to have a lot of "effective fiber" which also is organic material. In a ruminant, that slows down the rate of passage, resulting in better utilization of anything that goes into the animals mouth.
So, most people understand the value of a balanced diet that is full of the major nutrients, minor nutrients as well as protein, energy and fiber but why not the soil. So many people concentrate on N-P-K and in some cases pH, but what about the rest of the goodies that make soil into a productive living environment?
If people treated their soil more like a living enviroment and less like "dirt", your production would increase tremendously and it will help it sustain for many years to come. Healthy soil results in more tonnage per acre, higher protein, sugars and mineral content for your forages planted.
I'll cover this in a bot more detail in my March issue of the Back 40.