Field Water Budget of Subsurface-Drained Corn and Prairie Systems.

Bioenergy production systems have been proposed as a way to enhance United States energy security.  However, side-by-side comparison of field water budget components for such systems is currently limited.  The objective is to compare the effects of six bioenergy systems consisting of mixed prairie (nitrogen fertilized and unfertilized), continuous maize with 50 % stover removal (with and without cover crop), and maize-soybean rotation (each crop type grown each year) on field water budget components including subsurface drainage, deep vertical drainage, soil water storage, and evapotranspiration.  The study was done at the Iowa State University Comparison of Biofuel Systems (COBS) site located near Ames, Iowa which consists of twenty-four (27 x 61 m) individually tile-drained plots on Webster silty clay loam (fine-loamy, mixed, superactive, mesic Typic Ednoaquoll) and Nicollet loam (fine-loamy, mixed, superactive, mesic, Aquic Hapludoll) soils.  Production systems were replicated four times in a randomized complete block design.  Data from 2010 through 2012 will be presented.