September 2, 2020 | By Rupp Seeds
In many operations, soybean fertility (except for nitrogen (N)), is provided by the residuals from corn fertilization programs. To sustain optimum growth and maximize genetic yield potential, soybean plants require adequate amounts of the essential, secondary, and micronutrients.
Nitrogen, phosphorus (P), and potassium (K) are considered essential nutrients for soybean growth. Each soybean bushel removes an estimated 4.2, 0.4, and 1.25 pounds of N, P, and K, respectively.
Calcium (Ca), magnesium (Mg), and sulfur (S) are classified as secondary nutrients for most crops because of their importance for crop growth; however, the overall crop requirement for these nutrients are lower than that of the essential nutrients. Soybean use of the secondary nutrients is estimated at 0.2, 0.23, and 0.20 lb./bu. for Ca, Mg, and S, respectively.
Micronutrients (boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn)) are nutrients that are needed in relatively small amounts. Of the micronutrients, Fe and Mn are the most important for soybean production.
Regardless of the crop, maintaining soil pH is a critical component for maximizing yield potential. Soil pH for a soybean crop should be maintained between 5.5 and 7.0 with lime to help ensure the availability of fertilizer nutrients. Should soil pH fall below 5.5, the ability to fix N can be reduced. In general, noticeable fertility deficiencies in soybean are rare. Awareness of nutrient deficiency symptoms can help distinguish symptomology from foliar diseases, herbicide injury, sun scald, and other stresses.
Learn more about nutrient deficiency in soybeans and how to identify the symptoms in this issue of SeedScoop.Late Season Soybean Nutrient Deficiency Identification