Combining soil fertilization, cropping systems and improved varieties to minimize climate risks on farming productivity in northern region of Burkina Faso

In search of options to cope with climate change and variability, a trial combining fertilization and improved varieties of millet and cowpea (intercropped or as sole crop) was conducted on three sites (Lemnogo, Tibtenga and Ramdolla) in the northern region of Burkina Faso. The application of cattle manure (3 t ha−1), micro-dose (3 g hole−1 equivalent to 62 kg ha−1) of a mineral fertilizer composed of 14 % N, 23 % P2O5 and 14 % K2O (NPK), their combination and a control (no manure and no NPK) as four soil fertilization options, two improved varieties of millet (SOSAT-C88 and IKMP5), two varieties of cowpea (KVX 396-4-5-2D and KVX 61-1) and two cropping systems (millet–cowpea intercropping, sole crop) were tested on-farm for two seasons (2013 and 2014). During the third season a survey was conducted on the acceptability by farmers of the tested combinations as a way of buffering or coping with rainfall variability. Results Two-year trial revealed that the combination of manure and NPK applied to the intercropping of millet and cowpea significantly increased crop production (land equivalent ratio = 1.83 ± 0.18 and 1.78 ± 0.20, intercropping millet variety IKMP5 with cowpea KVX 61-1 and intercropping millet variety SOSAT-C88 with cowpea KVX 396-4-5-2D, respectively). During erratic rainfall year, intercropping millet IKMP5 and cowpea KVX 61-1 performed the best, while under well-distributed rainfall conditions, intercropping millet SOSAT-C88 with cowpea KVX 396-4-5-2D displayed higher production, respectively, for millet and cowpea. Some varieties were not well accepted by most farmers (based on a survey of 36 farmers) mainly because of loss in grains before harvest for millet IKMP5 (97 %) and high grain attacks by insects in storage for cowpea KVX 61-1 (89 %). The alternative for farmers rejecting these varieties could be the intercropping of millet SOSAT-C88 and cowpea KVX 396-4-5-2D fertilized with manure. Conclusions Making weather forecasts and related agronomic advices available to farmers in this region will allow them to better plan their agricultural practices such as mineral fertilizer application and will also be a great move toward climate-smart agriculture. Developing more performant storage measures that drastically reduce insect attacks for some of the tested varieties (cowpea KVX 61-1, for instance) could contribute to promoting their adoption