A New Experimental Design to Analyze the Value of Management Factors Contributing to High Corn Yield.

The objectives of this study were to determine the effect of the combination of technologies on corn yield and to assess their individual value. A field study was conducted at three 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 MicroEssentials 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. In addition, each high technology factor was independently added to the standard package and replaced from the high technology package by the standard level. The highest yields were obtained with the high technology package, which reached 17.2 Mg/ha in Champaign, 15.3 Mg/ha in Dixon, and 13.3 Mg/ha in DeKalb (which was severely affected by frost before maturity). The yield difference between the high technology system and the traditional management was approximately 30% in Champaign and Dixon. 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. Genetics was the management factor that had the most consistent effect followed by balanced crop nutrition and plant population. Single production factors cannot guarantee high corn yields, but rather it is the positive interaction among multiple factors that gives farmers the greatest opportunity to maximize yield.