Project title: Crop response to applied manure as affected by soil properties

Principal investigator:

C. Wortmann

Duration: 2002 to 2007

Funding: State funds

Contact:

Charles Wortmann Department of Agronomy and Horticulture, UNL, 154 Keim Hall, Lincoln NE 68583-0915, (402)472-2909 cwortmann2@unl.edu

Project description:

On-farm trials are conducted to determine how crops respond to applied manure relative to soil differences. Trials are laid out with manured and non-manured, but fertilized, strips across farmers’ fields. Trials have 5 or 6 replications and each replication contains 2 to 4 observation points for paired comparisons depending on soil and topographic variation. Four trials were established in 2002 and an additional 8 trials are to be established in future years.

Key results: Yield was constrained by severe water deficits in 2002 and the average corn and soybean yields were 100 and 36.3 bu/A. The average yield gains with manure, as compared to fertilizer, were 4.7 bu /A of soybean and 8.8 bu of corn. Variation in response to applied manure was often negatively related to variation in available soil P, exchangeable potassium, and soil organic matter.