R1:
Our pre-evaluation shows that seedballs have the potential to improve the Sahelian pearl millet cropping systems since the technology is mainly based on local resources and thus, can be adapted to local needs by individuals through added nutrient additives such as mineral fertilisers and wood ash. Additionally, seedball production does not conflict with other pre-seasonal labour loads or gender issues, and is coupled with low financial demands.
http://ijair.org/administrator/components/com_jresearch/files/publications/IJAIR_2740_FINAL.pdf
R2: Our results showed that the combination of 80 g sand + 50 g loam + 25 ml water is the standard seedball dough, which produces about ten 2 cm diameter-sized seedballs. Either 1 g NPK fertiliser or 3 g wood ash can be added as nutrient additive to enhance early biomass of pearl millet seedlings.
https://www.jarts.info/index.php/jarts/article/view/2019011596
R4: The seedball-induced yield effect is depending on a number of variables like geographic location, soil type, expected yield level (i.e. mainly soil fertility status), and applied additional fertilisation.
https://www.publish.csiro.au/CP/CPxyz