It is recommended to use microdosing in order to fertilize millet, sorghum and cowpea. This method is characterised by adding a small quantity of fertilizer into the pocket where the millet, sorghum or cowpea is sown. Fertiliser and seeds can be mixed in a 1:1 ratio (Doumbia et al. 2005). This mixing of seeds and fertiliser must be undertaken just shortly before sowing in order to avoid prolonged contact between seeds and fertilizer. The quantity of fertilizer to be used is about 0.3 g per pocket, corresponding to kg of fertilizer per hectare. DAP or NPK 16-16-16 may be used. In Mali, this fertiliser method has increased millet and sorghum yields by an average of 50%. This approach is particularly interesting for farmers who are not very well off. The photo above shows the microdosing effect on the yield (in the background).

The second fertilizer input (after having applied 0.3g) consists in applying 2g DAP or 6g NPK per pocket at the time of initial weeding, about 20 days after planting. An input of this quantity of fertilizer can more than double millet yields (Buerkert et al 2000). ICRISAT/JIRCAS research has demonstrated that delaying fertiliser application until 20 days after sowing does not decrease yield significantly as compared to applying fertiliser at the time of sowing. It is also possible to wait until 45 days after planting without the yield significantly diminishing compared to application of fertiliser at the time of sowing. It is more profitable to apply 2g of DAP than 6g of NPK, but the quantity of phosphorous applied is the same. This corresponds to 20 to 40 kg of DAP per hectare or 60 to 120 kg of NPK per hectare. The second fertilizer application may vary according to the rainfall and purchasing power of various farmers. Farmers may cancel or delay the second application in case of drought. In order to save fertilizers, the second application can only be given to plants that seem capable of producing more. A third application with urea is possible at the time of heading if the season is promising. 

Dry sowing is practiced in the northern parts of the Sahel. In such conditions, resowing is often necessary. The necessity to resow is reduced if 0.3 g of fertilizer is used, compared to g of fertilizer per pocket. The application of 2 to 6 g will lead to a loss if resowing is required. 

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Here is an article on results obtained in Mali on the use of microdose for sorgho and pearl millet production.

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