Winter Wheat and Row Crop Combinations for Grain, Silage and Biomass Production.

This project explores the agronomic and economic facets of crop rotations utilizing a winter wheat (Triticum aestivum) as the base grain or cover crop paired with second crops to be used as animal feed, bioethanol feedstock, or grain crops. Field experiments were conducted in 2008, 2009 and 2010 of various wheat/double crop rotations: grain production in wheat, sorghum (Sorghum bicolor), corn (Zea mays) and soybean (Glycine max), and silage yield and quality of corn, silage sorghum and sweet sorghum. Winter wheat was harvested for whole plant biomass at two early dates, (heading and mid-grain fill) and as grain with the straw later harvested for biomass.  Immediately following each wheat biomass harvest date, sorghum, corn, or soybean were no-till planted into the wheat stubble.  These double crops were then harvested for biomass and forage quality analyses at silage maturity or at physiological maturity for grain.  Forage quality analysis on ensiled biomass includes aerobic stability, crude protein, fiber, and lignin analyses, and ash content.  Triticale yielded significantly more biomass, silage, grain and straw than the winter wheat lines.  Triticale contained significantly more at α=0.05 indigestible fiber as NDF and ADF than the two wheat lines (67.6 and 41.1 versus 57.0, 56.5 and 33.1, 31.3% respectively).  Planting into wheat stubble at the first planting date significantly reduced total biomass yield for both sorghum and corn (17.5 to 14.0 and 16.4 to 12.6 Mg ha^-1 respectively).  At the first  planting date planting into wheat stubble resulted in a 3.37 Mg ha^-1 yield loss in grain corn, but only a 0.4 Mg ha^-1  loss for soybeans.  Preliminary data indicate that all ensiled crops can be considered 'high quality'.  The results of this research provide county educators and farmers useful data for recommending new or modified cropping systems to produce grain, feed and/or biofuel in response to specific market constraints.