Two Year Summary Evaluating Starter Fertilizers for Corn.

This study was designed to evaluate corn yield benefit of applying liquid and granular starter fertilizers directly in the seed furrow and 2x2 banded.  In 2007, five treatments were replicated four times in a randomized complete block design. The treatments consisted of four liquid corn starter fertilizer treatments applied directly in the seed furrow at time of planting and one untreated check.  In 2008, five treatments were replicated four times in a randomized complete block design. The treatments consisted of three liquid corn starter fertilizers directly in the seed furrow, a granular corn starter fertilizer 2x2 banded, and an untreated check.  Liquid starter fertilizers evaluated include: 2-20-18, 6-24-6, 8-19-3, 10-34-0; granular starter fertilizer consisted of 32-9-8.  Plot size was 0.35 acres in 2007 and 0.70 acres in 2008.  In 2007 and 2008, all plots received 45-0-0 banded 2x2 at planting and nitrogen sidedressed as 28% UAN at a range of 120-150 lb/acre at corn stage V4. Results from this two year study did not show any statistically significant differences in harvest population, moisture or yield for any of the starter fertilizer applications and the untreated check. Soil test levels for phosphorus and potassium in the study fields were above critical levels based on the Tri-State Fertility Recommendations.  Results from both years indicate that even small amounts of potassium or phosphorus in starter fertilizer blend are not likely to increase yields if soil test levels for those two nutrients are above critical levels.