Showing posts from July, 2016

Soil Health Key Points

NRCS fact sheet Soil Health Key Points lists “four ways to promote healthy soils.” First is keep your soil covered. A covered soil holds more water by binding to soil organic matter (SOM) and loses less water to runoff and evaporation. SOM increases when soil is covered by vegetation and dead plant material residue. SOM holds 18-20 times its weight in water and recycles nutrients for plants to use. One percent SOM in the top six inches of soil holds approximately 27,000 gallons or 1 acre-inch water. In addition, 1% SOM holds about 1,000# of nitrogen and roughly 100# each of phosphorus, potassium, and sulfur. Soil microorganisms exist in large numbers as long as there is a carbon source for energy. There are more microbes in a teaspoon of soil than there are people on the earth. Bacteria, due to their large numbers yet small size, tend to dominate in most tilled soils. Fungi populations may be 50 times smaller, but due to their larger size, they are similar in biomass to bacteria in und