Galt Porter of Mercer, Missouri, posted the top Iowa yield in this year’s National Corn Yield Contest, harvesting 405.13 bushels per acre in the strip/minimum/mulch/ridge-till non-irrigated category.

Porter also took first place nationally in his category, planting Pioneer’s P1742Q hybrid. Second place nationally went to Kogen Kalb of Dubois, Indiana, (401.79 bushels per acre) and Grey Porter of Mercer, Missouri, took...