Seed-placed starter fertilizer is an important planting practice for winter wheat. It has been shown to increase yields, on average, by 7.5 bushels per acre. The primary objective of a starter fertilizer is to provide nutrients for early growth and promote root development. This improves winter survival and crop uniformity the following spring. However, even though many studies indicate that starter fertilizer improves yield, there are a few challenges that have lead growers away from the practice. A critical issue regarding starter fertilizer is the application rate: how much do I have to apply to gain these benefits?
To test how well your money is spent on starter fertilizer, a visual demonstration simulating the spread of phosphorus fertilizer material (liquid and dry) at a range of rates was designed. This allows a determination of how close the fertilizer gets to the seed. As phosphorus does not move freely in the soil, it is critical that fertilizer be within 1 inch of the seed to allow the first roots to contact the fertilizer and receive the starter effect.
There are several different application methods used for starter fertilizer application. This experiment included an evaluation of both “surface broadcast” and “in the seed furrow” (in furrow) application techniques.