Managing Soil pH and Crop Nutrients

91 The inherent complexity of crop production systems requires integrating many factors to ensure maximum crop yields with the least risk to the environment. Assessing presentand reserved-nutrient status of the soil, understanding its nutrient-release and nutrient-holding capacity, and knowing the plant and environmental factors that impact nutrient availability are necessary to guide fertilization rates, sources, and method of application of additional nutrients. The information here is intended to provide fundamental principles to help the reader understand what to do, and why, when making management decisions related to phosphorus (P), potassium (K), secondary macronutrients (calcium [Ca], magnesium [Mg], and sulfur [S]), micronutrients (boron [B], chlorine [Cl], copper [Cu], iron [Fe], manganese [Mn], molybdenum [Mo], and zinc [Zn]), and pH.