Geo-referenced crop-nutrient response function dataset for Tropical Africa

The profit potential for a given investment in fertilizer use can be
estimated using representative crop nutrient response functions. Where
response data is scarce, determination of representative response
functions can be strengthened by using results from homologous crop
growing conditions. Maize (Zea mays L.) nutrient response functions were
selected from the Optimization of Fertilizer Recommendations in Africa
(OFRA) database of 5500 georeferenced response functions determined from
field research conducted in Sub-Saharan Africa. Three methods for defining
inference domains for selection of response functions were compared. Use
of the OFRA Inference Tool (OFRA-IT; http://agronomy.unl.edu/OFRA)
resulted in greater specificity of maize N, P, and K response functions
with higher R2 values indicating superiority compared with using the
Harvest Choice Agroecological Zones (HC-AEZ) and the recommendation
domains of the Global Yield Gap Atlas project (GYGA-RD). The OFRA-IT
queries three soil properties in addition to climate-related properties
while the latter two options use climate properties only. The OFRA-IT was
generally insensitive to changes in criteria ranges of 20–25% used in
queries suggesting value in using wider criteria ranges compared with the
default for information scarce crop nutrient response functions.