What would be the minimum nitrogen input required for growing maize at a certain location in Sub Saharan Africa? At Kind of Green®, we’ve recently developed a mobile Android app to answer precisely that question, based on knowledge from Wageningen University, the Netherlands.
Agricultural area expansion and agricultural intensification in Sub Saharan Africa (SSA) are expected to cause substantial increases in agricultural GHG emissions over the next decades. The Crop Nutrient Gap project explores ways to substantially improve food productivity in SSA (Ethiopia, Kenya and Tanzania) without corresponding increases in emission intensities of GHGs and nutrients to the environment.
As nitrogen fertilization is a main contributor to agricultural greenhouse gas emissions, an important concept developed by the Crop Nutrient Gap project is the minimum nitrogen input requirement: the minimum amount of nitrogen needed to replace all N taken up in the aboveground crop biomass (stover and grain) for that specified target yield. A detailed rationale behind this definition is provided here.
The app that will be demonstrated calculates the minimum nitrogen input requirement for maize, based on a location-specific ceiling yield (the water-limited yield potential, which can be derived from e.g. the Global Yield Gap Atlas), and a user-provided target yield. Whereas the minimum N input requirement might be particularly relevant for policy makers and scientists, the app’s functionality may be extended in the future to provide advice to local farmers. Versions for Mac OS and Windows Mobile are on the way too.