Introducing ² Nlos On the Web (NOW)² - a New Nitrogen Management Tool for Extension, Education and Research.

There is growing pressure on farmers to increase crop production on limited land and with minimum inputs while reducing the footprint on the total environment to near zero. Many cropping tools to help farmers manage crops are under development, such as precision spatial management, remote sensing, delayed release nutrients and in-season nutrient application. Improved crop management will also depend more on knowledge tools such as soil-system models to track and predict soil processes and crop responses. Currently most models are post facto which cannot help with real-time decision making.  Real-time models such as the Cornell PNM model have proven helpful to farm advisors communicating the complex soil-crop system to producers. However, most soil models now in use are black boxes which cannot readily be adjusted to new circumstances or information. The new web-based version of NLOS is based on the USDA NLEAP model developed by Marv Schaeffer et al. at Fort Collins. Our model adds  two critical features: 1. the model runs on the web in real time using daily weather data grabbed from online weather stations and customized weather stations if available; 2. the model is written in the icon-based STELLA platform which facilitates modification, especially for non-modellers. The new NLOS has a general user layer which allows users to easily input soil and activity information and to select from a wide range of model variables. A second layer is available to advanced users, which allows manipulation of several internal model parameters to enable simple model calibrations. For more ambitious users, the entire model in its iconic format is also available for offline use. A hosting system will be developed to allow spawning on the web of new specialized versions of the original NLOS model in Wikipedia-like fashion.