The International Plant Nutrition Institute (IPNI) has completed a summary of results of tests performed on approximately 4.4 million soil samples collected in the fall of 2009 and spring of 2010 to compile maps and reports on the nutrient content of soils in the U.S. and Canada. It compiled soil sampling data to report on phosphorus, potassium, sulfur, magnesium, zinc, chloride, and pH. This