This North Central Extension-Industry Soil Fertility Conference (2015) bulletin by Mallarino, Camberato, Kaiser, Laboski, Ruiz-Diaz, and Vyn synthesizes multi-state micronutrient trials for corn and soybean. Overall: micronutrient deficiencies are not widespread in the north-central region and mostly occur on sandy, calcareous, or high-pH soils. Indiana: soybean Mn response was inconsistent; one 2007 trial on a Mn-deficient soil (Mehlich-3 Mn 12 ppm) showed a 6 bu/acre yield increase from foliar or banded Mn combined with starter N-P, but Mn alone gave no benefit, and results varied 5-15% and by location/year. Iowa: 2012-2014 trials across 30+ soil series (46 soybean, 11 corn fields) testing foliar/soil B, Cu, Mn, Zn found no statistically significant yield response at any conventional-plot trial; existing soil/tissue sufficiency interpretations over-predicted deficiency response. Kansas: seed-applied chelated ortho-ortho EDDHA-Fe increased soybean yield ~55% on severe iron deficiency chlorosis (IDC) soils (pH 8.1-8.5), but foliar Fe had no effect; separate trials found no yield benefit from starter/foliar B, Cu, Mn, Zn blends in corn or soybean without a deficiency history, except one sandy site with a 6 bu/acre gain from broadcast micronutrient mix. Minnesota: Fe (as o-o-EDDHA "Soygreen," 3 lb/acre on seed) increased soybean yield 3-4 bu/acre in IDC-prone areas; other micronutrients (Zn, Mn, Mo, B) showed no consistent yield benefit across 12 site-years, and 2 lb B/acre broadcast occasionally reduced yield. Wisconsin: three years of starter/foliar Mn trials (0-5 lb Mn/acre starter; 1.25 lb Mn/acre foliar at R1/R3) found tissue Mn below sufficiency ranges (54-300 ppm) at all sites, yet no consistent yield response, suggesting the sufficiency range may be too high. Overall conclusion: soils in the region generally supply adequate micronutrients for corn/soybean; Fe management for IDC is the clearest exception with proven response; decisions on other micronutrients should target only sandy, calcareous, organic, or severely eroded fields rather than broad application.