The USDA has produced an 88 page guide for measuring soil quality. Agriculture Solutions LLC strongly advocates the use of soil testing to understand the quality of your soil which in turn determines the quality of your food and your health. It gives a good outline of measuring pH, EC, Nitrates, how to sample, problems to look for and much much more. This guide is free and we provide the link below. Remember many of the instruments needed for these soil tests are available in our "Plant and Soil Testing" products category.