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  • Cecilia Wandiga

Kenya Sustainable Cities - Reducing Agrochemical Farm Water Runoff


Kenya's economy is predominantly agrarian. This can be a significant benefit if we focus on value addition and Bio-Economy transitions. 

An overview of the various disciplines needed for a successful Bio-Economy can be found here

https://www.csti.or.ke/human-centred-design

Countries like Israel defy assumptions about what is possible when agricultural land is scarce. 

https://www.the-star.co.ke/news/2016/07/14/kenya-israel-relations-will-boost-farming_c1385550

https://www.nation.co.ke/business/seedsofgold/Israel-leads-the-way-with-successful-private-and-communal-farms/2301238-2718050-s7jkq1z/index.html

http://sbs.strathmore.edu/blog/2013/11/26/agri-business-what-kenya-can-learn-from-israel/

In addition to learning about dryland farming techniques, we can use Israel's desert farming success to imagine the type of farming that is possible within cities (arable land and access to large fresh bodies of water are scarce in cities). 

A common need in all locations is fresh water that is free of pollutants and toxic chemicals. The first step towards improved water quality is preventing farm run off. Fertilisers, pesticides, herbicides, etc are chemicals used to improve agricultural yields but they have an adverse impact on fresh water systems (including getting into the fish we eat which means we are eating these chemicals). 

https://www.npr.org/sections/thesalt/2013/07/09/199095108/Whats-In-The-Water-Searching-Midwest-Streams-For-Crop-Runoff

One solution is to dig shallow tracks and swales or raceway ponds that capture and redirect runoff water. 

https://www.landcareresearch.co.nz/publications/newsletters/soil/issue-26,-october-2017/maximising-the-value-of-irrigation

https://www.cleveland.com/insideout/index.ssf/2012/03/a_rain_garden_in_you_yard_can.html

https://www.treetrays.co.za/trees/using-swales-grow-trees/

http://www.sustainableworks.org/news/rain-gardens-capture-water-it-becomes-urban-runoff

Another solution is to plant trees and shrubs that filter and the flow of farm water runoff. The same can be done along the banks of rivers and lakes. 

This guide from New Zealand provides details

https://www.waikatoregion.govt.nz/community/your-community/for-farmers/waterways-and-wetland-management/

To recoup value from the cost planting and maintaining trees and scrubs, focus on species with high economic value. 

Trees that produce higher quality honey, fuits or nuts in low pH and low fertility soils include acacia, Baobab, black plum, macadamia nut, passion fruit, tamarind and bixa (bixa orellana aka achiote, annato, lipstick tree, urucum) . The benefits of such trees is they attract bees which boost agricultural yields through natural pollination. 

https://www.kenyacic.org/projects/every-acacia-hive

Growing high priority fruits and nuts in Kenya - World Agroforestry Centre

http://www.worldagroforestry.org/downloads/Publications/PDFS/B15956.pdf

https://www.nation.co.ke/business/seedsofgold/Wonder-crop-that-colours-my-pockets/2301238-2372440-gwbruk/index.html

This handy guide shows the trees that are best for each eco-zone in Kenya. 

https://www.infonet-biovision.org/EnvironmentalHealth/guide-tree-planting-Kenya

Groundcover orchids, aloe and fertiliser shrubs such as Tithonia diversifolia (aka tree marigold, Mexican tournesol, Mexican sunflower, Japanese sunflower, Nitobe chrysanthemum) are good for farm borders and fencing 

http://www.ngkenya.com/flora/eulophia-01.html

http://www.ngkenya.com/flora/aloe-02.html

http://www.ngkenya.com/flora/oxalis_obliquifolia.html

https://www.standardmedia.co.ke/article/2000185720/leaves-from-a-local-shrub-can-help-boost-soil-fertility

Reducing chemical use by increasing the use of vermicompost and mulch is also helpful. 

https://www.infonet-biovision.org/EnvironmentalHealth/How-improve-soil-fertility

Fertiliser trees (nitrogen fixation trees) can be intercropped

http://blog.worldagroforestry.org/index.php/2015/04/16/fertilizer-tree-options-for-farmers/

https://www.nation.co.ke/business/seedsofgold/The-gold-in-acacia-trees/2301238-3907240-q5p2mxz/index.html

CSTI research in Makueni showed sand dams are effective in reducing the impact of heavy rains.

https://www.csti.or.ke/appliedresearch

Nature is our friend when we learn to understand how to integrate the flow of natural systems into the flow of human systems.  

What are ways in which you can apply this knowledge on your farm or in your city garden?


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