Nitrogen management for corn may be improved by applying a portion of N during the growing season. This allows N fertilizer availability to more closely synchronize with the time when the crop is rapidly up-taking nitrogen. Growers who are interested in sidedressing a portion of fertilizer nitrogen are encouraged to take a look at Maize-N, a decision support tool for N recommendation.
Maize-N is a computer program developed at UNL that simulates fertilizer requirement for corn. The estimation of N fertilizer requirement in Maize-N is based on user input information on the current corn crop, last season crop, tillage, crop residue management, basic soil properties, fertilizer management, and long-term weather data of the field. The program first simulates corn yield potential and its year to year variation. It then estimates the economically optimal N rate of fertilizer to apply.
The Maize-N model adopts the core functions from the Hybrid-Maize model (Yang et al., 2006) for corn yield prediction, and Yang and Janssen (2000) for N mineralization from soil organic matter, and generic response of corn yield to N uptake. This model has been validated in experiments in central Nebraska, eastern South Dakota, and western Nebraska, including both irrigated and rainfed systems (Setiyono et al., 2011). The economic optimum N rate (EONR) simulated by Maize-N and the EONR generated with more empirical university N recommendation approaches were compared to actual observed EONR; EONR simulated by Maize-N was found to have greater accuracy than the university N recommendation approaches.
This year, the Nebraska On-Farm Research Network is working with a number of growers to evaluate Maize-N. The study involves 2 treatments:
1. Producer's sidedress nitrogen rate
2. Maize-N sidedress nitrogen rate.
There is still time to get involved with this project and evaluate this tool for nitrogen management. You can schedule a meeting to go through Maize-N and generate the nitrogen recommendation for your field by contacting Laura Thompson, firstname.lastname@example.org, or 402-624-8033.
More information about the Maize-N study is available at http://go.unl.edu/MaizeN.
Setiyono, T.D., H. Yang, D.T. Walters, A. Dobermann, R.B. Ferguson, D.F. Roberts, D.J. Lyon, D.E. Clay, and K.G. Cassman. 2011. Maize-N:A decision tool for nitrogen management in maize. Agron. J. 103:1276-1283.
Yang, H. S. and B.H. Janssen. 2000. A mono-component model of carbon mineralization with a dynamic rate constant. European Journal of Soil Science. 51:517-529.
Yang, HS, A. Dobermann, K.G. Cassman, and D.T. Walters. 2006. Features, applications, and limitations of the Hybrid-Maize simulation model. Agron. Journal. 98:737-748.