The use of starter or pop up fertilizer is common practice across the Corn Belt, but with tight profit margins on the farm, growers are looking to reduce expenses. Can corn farmers reduce or eliminate starter fertilizer from their fertility program without a heavy impact on yields?
Advantages to starter fertilizer use is often visual, with faster early growth and dry matter accumulation. This means faster development of crop canopy, earlier pollination and maturity, and usually a 0.5 to 1.5 percent drier grain at harvest. The drier grain is likely the result of plants reaching physical maturity earlier, while fall weather is warmer and more suitable for advancing grain dry down.
Starter fertilizers contain phosphorus in approximately a 3:1 ratio with nitrogen, and can sometimes contain other nutrients in very small amounts including potassium and sulfur. Zinc can be added to starter formulations, and has shown improvements in stand emergence and seedling vigor. Despite some differences in formulation, starter fertilizers provide similar benefits when banded in close proximity to the seed.
Results will be most favorable in cool, wet soils often associated with early season planting and no-till or minimum tillage environments. Banding fertilizer also has an advantage in soils where phosphate fixation is a problem. These soils would include acidic soils below 6.0 pH, calcareous soils above 7.0 pH, or soils with low soil test values. In these environments, dry fertilizer applied phosphorus is often fixed into non-soluble forms that are unavailable to the plants. Fertilizer placed in a band are more resistant to fixation, thus more available to the plant for a longer period of time.
Using starter fertilizers do not guarantee higher yields; however, they do often result in better early season performance, which does often contribute to better yielding crops.