Project Number: 5440-12210-050-02
Project Type: Reimbursable

Start Date: Oct 01, 2007
End Date: Mar 31, 2009

Objective:
Determine the amount of corn stover residue needed to maintain soil C content (soil quality) and crop productivity.

Approach:
The investigation was initiated in 2001 at the University of Nebraska Agricultural Research and Development Center, near Mead, NE, as a randomized complete block experiment (six blocks) with a split plot treatment arrangement. Tillage treatments (fall disk or no tillage) are assigned to whole plots. Residue removal levels (0, 50, or 100%) are assigned to subplots. Subplots are 15.2 m by 9.1 m (12 rows). Residue removal treatments are applied after grain harvest by collecting stover with a flail-type forage chopper. No stover is removed from the 0% treatment, all stover is removed from alternate pairs of rows in the 50% treatment (switching the rows from which stover is removed in alternate years), and stover is removed from all rows in the 100% treatment. Plots assigned to the disk tillage treatment are tilled after stover removal treatments are applied. In Spring, disk treatments is tilled again and the entire experiment is planted to corn in late April. The crop is managed with practices (fertilizer, pesticides, irrigation, etc.) customary for the region. Corn in the disk treatment is cultivated at about V6. At the beginning of the experiment, soil samples were collected. Analyses were conducted for soil chemical, physical, and biological parameters as outlined in the Statement of Work. Annually corn grain and biomass yield and N content are determined. In addition, mass of stover retain on the land and surface cover is measured. Soil chemical, physical, and biological parameters will be determined at intervals during the course of the experiment and at the termination of the study as outlined in the Statement of Work.