A first series of soil improvement research trials was done in 2009 to determine the effect of fertiliser on survival and growth of mukau and Jatropha. Different doses of a commercially available agricultural fertiliser were applied, with clearly discernible effects on survival, growth and health of mukau seedlings. The fertiliser used so far (Mavuno) has a high phosphorous content, good for kick-starting a vigorous root system, and also includes trace elements like zinc (Zn) and boron (B).
Initial results show that an application of 50g at planting seems to be the best option so far. Growth and vigour are enhanced, and possibly resistance against the red spider mite (Tetranychus urticae) though more research has to be done for confirmation. This research was done in cooperation with the University College of Ghent, Belgium, as part of a Master of Science (MSc) thesis.Another series of trials is under way, regarding fertiliser of one-year-old mukau plantations, as well as defining the components for an ideal tree fertiliser for red tropical soils in drylands.