Evaluating Individual and Cumulative Contributions of Corn Production Inputs to Address Yield Gaps.

The objectives of this study were to determine the effect of the combination of different proven technologies on corn yield and to assess their individual value. A field study was conducted at two locations in Illinois using an “Omission Plot” design. The factors under study at a standard best management level and a high technology one were: genetic resistance to corn rootworm (non- and resistant isohybrids), plant population (80 and 110 thousand plants/ha), P-S-Zn nutrition (no application of fertilizer based on soil P test and application of 100 kg/ha P2O5 as MicroEssentialsTM SZ , nitrogen (180 kg N/ha as UAN and an additional application of 100 kgN/ha as SuperU), and fungicide (with and without fungicide). The standard and high technology packages consisted on all factors at the low level and high technology levels, respectively. The highest yields were obtained with the high technology package in all site-years, which reached 17.2 Mg/ha in Champaign and 15.3 Mg/ha in Dixon. The average yield difference between the high technology system and the traditional management was 28% (2.9 Mg/ha). No single factor accounted for this yield increase. Kernel number showed a stronger correlation with yield than kernel weight. The response to all management factors was larger under the high technology system than under the traditional management. In all cases the value of a given factor when combined with the other factors in the high-technology package was substantially greater when that factor was provided alone.