Briefly, I am a Danish agronomist doing research, training, lecturing and consultancies for a number of years in tropical agriculture and agroforestry with focus on soil fertility, soil and water conservation, hedge management and particularly low-input establishment of multipurpose tree legumes (family of beans) like calliandra.
I have developed and studied methods making direct seeding easy, low-cost and reliable of such trees at least in the humid and subhumid tropics. Standard guidelines to farmers often results poor germination, survival and/or unsustainable adoption. One of the methods includes proper use of wood ash as a source of e.g. phosphorus, and another, effective local transfer of nitrogen fixing bacteria. Often the tree legume seeds do not take up water or do it too late with standard methods recommended to farmers (1-3 days time cold water soaking). We got 87% field germination in 2 weeks without watering and hedges reaching about 2 m after six months in infertile soil, both results more than twice as good as zero-treatments, but some of details in the methods should be followed to avoid damage.
For an overview, practically relevant, research article Google e.g. Torsten Mandal xps or use www.folketinget.dk/samling/20061/almdel/URU/Bilag/256/397668.PDF
I am married with a wife from rural Kenya and have three children all living in Denmark with close contact to Western Kenya.