Starter fertilizer may be needed on soybeans depending on soil test levels
By David G. Hallauer
Meadowlark Extension District Agent
It’s estimated that soybeans will use eight-tenths of a pound of phosphorous and one and four-tenths pounds of potassium per bushel of yield. Because they fix their own nitrogen, we often tend to simply forget about that nutrient use, but in general, nutrient use levels can become pretty significant. Do we need to make up for that high nutrient use by applying a starter?
It depends. As a general rule, on medium to low soil testing sites, some level of fertilization above and beyond what we think may have “carried over” from what we applied to the previous corn crop is necessary. Soybeans will tend to respond in those situations.
If soil test levels are in the high category, little response will likely be seen and no application may be necessary unless suggested by a soil test. Further, because we tend to plant soybeans after air and soil temperatures have risen (and stayed that way), our chance of a response like what we might see in corn is limited.
If a soil test indicates a need for P, or K, or anything for that matter, a fertilizer application to soybeans is in order. Broadcast applications might suffice, but at very low levels, if banding to the side and below the seed at planting is recommended—particularly in no-till because of limited mobility issues with some nutrients. Just be sure not to place fertilizer in direct contact with seed due to its intolerance to salt injury.
Nitrogen needed? Probably not, unless you are in an irrigated/high-yield environment.