Wheat is considered a highly responsive crop to starter fertilizers, particularly phosphorus and nitrogen. Application of P as starter fertilizer can be an effective method for part or all the P needs. Wheat plants typically show a significant increase in fall tillers and better root development with the use of starter fertilizer (phosphorus and nitrogen). Winterkill can also be reduced with the use of starter fertilizers, particularly in low P testing soils.

Phosphorus fertilizer application can be done through the drill with the seed. This would be either in addition to, or instead of, any preplant P applications depending on soil test and recommended application rate. The use of dry fertilizer sources with air seeders can be a very popular and practical option, however, other P sources (including liquid) are agronomically equivalent and decisions should be based on cost and adaptability for each operation.

When applying fertilizer with the seed, nitrogen and potassium (K20) rates should be limited to avoid potential toxicity to the seedling. When placing starter fertilizer in direct contact with wheat seed, producers should use the following guidelines in Table 1. (No urea-based N should be applied with the seed in any row spacing or soil type.)

Air seeders that place the starter fertilizer and seed in a band an inch or two wide, rather than a narrow seed slot, provide some margin of safety because the concentration of the fertilizer and seed is lower in these diffuse bands. In this scenario, adding a little extra N fertilizer to the starter is less likely to injure the seed — but it is still a risk.





Information provided by Dorivar Ruiz Diaz, K-State Extension Nutrient Management Specialist.
