By Cathy Watson
On 4 July, World Agroforestry was delighted to host the Dudutech symposium, TreeTech 2019 – Growing Avocadoes in a New Era. Rarely had so many private sector players been inside the walls of the Centre that is best known as ‘ICRAF’.
ICRAF’s Dr Catherine Muthuri gave the opening words, welcoming the participants to the Centre of science and development excellence that is headquartered in Nairobi and has 200 staff in Kenya and about 200 scientists worldwide. Muthuri said ICRAF’s focus is integrating trees into farming for multiple benefits such as soil fertility, fruit, fuel, fodder, wind reduction, microclimate modification, shelter for bees and other beneficial insects.
The Acting Regional Director for Eastern and Southern Africa also said that farms hold on to a small fraction of rain that falls. Most rainwater simply runs off. But maintaining and adding trees to farms will make the land more ‘water efficient’. Trees intercept rain and hold water around their roots and in the soil organic matter that they create.
ICRAF researcher Maimbo Malesu also addressed the participants on water, saying, ‘with rainfall of 1000-1200 mm a year, you need water harvesting to get enough for partial or full irrigation’ and that this can easily be captured in ponds that harvest runoff. Such ponds increase farm productivity so much that they pay for themselves within three years.
To an extent, it was observed, cultivating avocadoes is a form of reforestation or at least ‘re-treeing’. Avocadoes can be grown as hedgerows that are pruned yearly.
Some of the most memorable messages came from John Ogechah, who said that soil biology had been neglected for too long. Calling for more natural farming, he said soluble salt fertilizers suppress the mycorrhiza that play a vital role in plant uptake of nutrition.
He said cultivation can slice hyphae networks and bury spores below root zone delaying colonization. He said compost was a living fertilizer teeming with microbes and that organic carbon is a ‘house’ for microbes. ‘Therefore, compost is an ideal way to inoculate soils with beneficial microbes,’ said the Dudutech training manager.
At lunch there was a lot of excited discussion about the potential of avocado in Kenya. But a caution was sounded on the mold, Phytopthera, which decimates fine roots which take up nutrients and water.
ICRAF looks forward to the next Dudutech TreeTech event in 2020. Will it be on macadamia or maybe mango? We look forward to hearing and to hosting it.
Cathy Watson is chief of programme development at ICRAF. She writes at: http://blog.worldagroforestry.org/index.php/author/cathy-watson/