Upper washita river experimental watersheds: land cover data sets (1974-2007) for two southwestern oklahoma agricultural watersheds.

Land cover data sets were developed for 1997, 1999, 2003, 2005, 2006, and 2007 for the Little Washita River and Fort Cobb Reservoir experimental watersheds (LWREW and FCREW, respectively), located in southwestern Oklahoma, to support remote sensing based studies of soil water content. A previously unpublished retrospective land cover analysis covering the years 1974, 1981, 1985, 1989, and 1994 was conducted to complement these data sets to gain a sense of the dynamics of land cover in both the LWREW and FCREW over the 33 yr. Each of these studies used satellite-based sensors of various spatial, radiometric, and spectral resolutions, but the number of images used, image date, and methods used to analyze the images varied from study to study.

EPIC modeling of soil organic carbon sequestration in croplands of Iowa.

Depending on management, soil organic carbon (SOC) is a potential source or sink for atmospheric CO(2). We used the EPIC model to study impacts of soil and crop management on SOC in corn (Zea mays L.) and soybean (Glycine max L.