By: Dan Kaiser, Extension nutrient management specialist Travelling around Minnesota the last few years, it has become apparent that the concept of “base saturation” is alive and well across the state. I recall one person commenting that they have moved on to a more advanced fertilization strategy by looking at cation ratios for managing crop nutrients, which inherently comes back to base saturation. I figured it would be a good time to lay out what base saturation is and what the current research says about it when it comes to managing crop inputs. What is base saturation? The idea of base saturation and cation ratios are not new. Some of the earliest research dates to the 1940s and 1950s, so this is not a new concept. We know that the cation exchange capacity (CEC) is the capacity of the soil to retain positively charged ions (cations), which can be considered bases. The cations include potassium (K), calcium, magnesium, and sodium, as well as hydrogen and aluminum. The theory is tha...
