Grain and Biomass Nutrient Uptake of Conventional Corn and Their Genetically Modified Isolines.

The introduction of genetically engineered crops within the United States has increased dramatically over the past decade. The initial adoption coincided with the release of herbicide-tolerant soybean (Glycine max) production with a 54% adoption within the United States, in contrast adoption of herbicide-tolerant corn (Zea mays L.) was only 6 % in 2000. The percent of soybeans planted for the 2009 growing season was 91 %, with 22 % herbicide-resistant corn. The majority of genetically engineered corn planted in the US is 78% which is comprised of 17 % insect-resistant, 22 % herbicide-tolerant and 46% as stacked genes. With this significant increase in adoption by producers several questions have been asked and are being evaluated included the impact on plant, insect, disease and microbial communities, environmental and ecological impact. The experiment was established in the spring of 2005 at the Eastern South Dakota Soil and Water Research Farm near Brookings, SD. The experiment was conducted as a completely randomize design replicated four time, within a two-year corn/soybean rotation with each phase of the rotation was present each year, in two adjacent areas (each 930 m2). Experimental treatments included 18 different commonly used corn hybrids each with the conventional hybrid and corresponding transgenic modifications. Crop biomass production, yield and nutrient uptake were measured and will be evaluated.