Early season scouting is imperative to good nutrient management in alfalfa. In Minnesota, the main nutrient concerns lie in sulfur, potassium and boron. Read on for tips on how to scout for and manage these common alfalfa deficiencies. Sulfur In Minnesota, sulfur deficiencies in alfalfa are found in two main areas: 1) sandy soils where sulfur tends to leach rapidly; or 2) soils with low organic matter content that have a limited capacity to mineralize sulfur. Scout for yellowing in the upper leaves and thin stands. The most susceptible areas of the field will be sandy soils with low organic matter and eroded knolls within in the field.