Evaluation of Variable Seeding Depth and Corn Yield Across Three Cornbelt States.

A prompt and even plant emergence in corn (Zea mays) production is necessary to achieve high yield potential. However, field studies have shown great plant-to-plant variability in terms of emergence and early plant development. It has been shown that uneven plant development could lead to yield loss due to the inability of corn plants to fully compensate for the yield lost by underperforming neighboring plants. In the current study, it is hypothesized that the soil moisture variability found at the seeding depth could be largely responsible for uneven corn emergence and early plant development. Within-field soil moisture is variable due to soil texture and landscape positions (i.e. ridges, depressions, and sloping ground), and this moisture variability is markedly present at the top 3 inches of soil in which corn is commonly planted. A research project in collaboration with corn growers across three Midwest states and the University of Illinois Crop Education and Research Center was conducted during the 2014-2015 growing seasons to evaluate the yield impact of variable seeding depth. Treatment strips at depths of 1, 2, and 3 inches were planted across the entire length of fields to capture the soil moisture variability found in various landscape positions. Preliminary results show yield increases of shallower planting in moist field areas compared to the regular depth used by corn growers.