Nitrogen Recalibration for Corn in North Dakota

The nitrogen (N) recommendations for corn in North Dakota (ND) need to be updated using actual field results from ND. Existing recommendations are based on Minnesota data, and older ND field calibration data. There have been many changes in cropping systems especially conservation tillage adoption, weed control, and corn hybrid genetics. Many of the newer hybrids are more resistant to water limiting conditions experienced in parts of ND. The study will consist of N response research experiments at a number (8 to 10) of sites depending on resources and locating suitable field research sites. This study will be conducted for two years to generate data for up to 20 site-years of research results.


22 Jan 2013

2012 Annual Interpretive Summary

Field research on this project has progressed well. The third year of a four year project has been completed in the 2012 crop year. A total of 64 site-years of experiments have been conducted so far. Only eight site-year experiments have been abandoned and data not included because of problems with flooding (6 site-years), inadequate stand establishment (1 site-year) and deer damage (1 site-year). The data are being clustered and analyzed separately by combinations of soil texture and general geographic location, as well as length of time of no-till cropping [e.g. eastern North Dakota (ND) high clay soils; eastern long-term no-till soils; eastern ND medium textured soils; and West River soils]. This is done to improve the R-squared value for N response curves, correlating total available N and corn yield. Grouping all the sites into one correlation curve does not seem effective. Not only are data being collected to assess yield response to total available N at the sites, but economic analysis is being done by generating gross returns per acre in dollars from application of N at the rates of total available N based on the three possible corn prices of 5, 6 and US$8. Supplemental N fertilizer rates are 0, 40, 80, 120, 160, and 200 lb N/A at each site.

Detailed research has been conducted at 38 of the 64 sites, mostly eastern ND sites, evaluating the effectiveness of using crop sensing technologies to estimate crop yield potential, and develop alogrithms for in-crop variable rate supplemental N. The technologies being evaluated are Greenseeker® and Crop Circle®. Readings are being taken at two crop stages (i.e. 5 to 6 leaf and 10 to 12 leaf stages). In practice, a grower will establish an N-rich strip (200 lb N pre-plant applied, width of the applicator and 100 ft. long). The side-dress applicator has at least one sensor and the appropriate algorithm for soil and location. The grower will use the N-rich strip as the base reference. Any readings below an established ratio will be fertilized to the appropriate rate with the applicator. This additional work is in the early stages and associated with a National Science Foundation grant. Field research will be completed in the 2013 crop year, and the final report is planned to be released in 2014. ND-16