Maize Yield Prediction in Burkina Faso.

Nutrient omission trials were conducted on several soil types and across a range of climatic conditions in Burkina Faso over several years. The trials were conducted to develop site specific fertilizer recommendations for maize and to provide farmers with optimized maize production recommendations. DSSAT v4.5 (Decision Support System for Agrotechnology Transfer) was used to analyze management options after data sets from West Africa were used to calibrate the model. Two varieties of maize were used; a long duration (120 days), SR22, and a medium duration (90 days), FBC6.  Four sowing dates (15 April, 15 May, 15 June, 15 July), four levels of nitrogen (0, 40, 80, 120 kg ha^-1) and three levels of both P (0, 30, 60 kg ha^-1) and K (0, 40, 80 kg ha^-1) were combined to create DSSAT experimental files for simulations. Model inputs to the system were compiled and included both daily weather data (precipitation, temperature, and solar radiation) from 1997 to 2007 from 10 meteorological synoptic stations encompassing the entire country, and the analytical characteristics of eight main soils types of Burkina Faso. To generate recommendations, the data was integrated with the Climate Information Toolkit, which provides a framework for simulating and analyzing outputs from regional scale simulations of cropping systems. In comparing 288 management options, preliminary results showed that the best overall sowing date is in June; in southwest Burkina Faso, the optimal sowing date is in May and in the north, the latest sowing date is in July. Cultivar response differed according to location; SR22 did better in the west and FBC6 in the east. The optimal NPK fertilizer recommendations were in accordance with most of the nutrient omission trials, which showed that N is the most limiting nutrient, followed by P. The results showed that K was not a limiting nutrient, and as such the economic optimum is with minimum potash application. Maize grain yields ranged from 1 to 5.4 t ha^-1.