Fanya Juu



Image: Hanspeter Liniger

Similar names: terracing, retention trenches, infiltration trenches

The name Fanya juu means “throw it upwards” in Kiswahili and it is very similar to Fanya chini as it consists of terrace bunds and ditches along the contour. The goal of contour bunds is different depending on the environmental conditions of the areas within which they are applied.  Their aim in semi-arid areas is to harvest and conserve rainfall, whereas, in sub-humid zones, contour bunds are constructed to discharge excess runoff. However, their main purpose is to prevent water and soil loss and to make conditions more suitable for plants to grow. Fanya juu is suitable for slopes of 5-20%, similar to the ones that characterize Fanya chini interventions.

  • Increase vegetation
  • Erosion prevention
  • Water harvesting
  • Increase crop yields

  • Maintenance: the bunds need annual build-up and maintenance: the grass strips require trimming to keep them dense and low to prevent them from burning during the dry season.
  • This intervention requires more work than Fanya chini.
  • A small loss of agricultural land will be inevitable for the construction of the trenches. However, this can be limited by integrating vegetative measures such as growing grasses or trees which can be used for fodder in-between the trenches.
  • Controlled grazing: grazing should be well managed and controlled so as not to damage the structure. See the “grazing management” intervention for more details on how to do this.


  • Hoe (Jembe) or shovel
  • Pickaxe (for hard soils)
  • Ox-drawn plough or excavating machinery for a more efficient excavation
  • Wooden triangular right-angle frame (or something to measure 90 degree angles)
  • To measure the contour line, here are some examples of tools that could be used:
    a string line level or spirit level instrument, hose pipe half filled with water, bottle of water half filled with water, A-frame level. An alternative would be to ask a person who is acquainted with measuring levels (such as a masonry worker) which tool they use, and you can use the same approach to measure your land.

The preferred distance between the terraces depends on the slope and soil depth. The earth bunds are built by digging a trench of typically 50-60 cm deep and 60 cm wide, and by relocating soil upslope in order to form the bund. It is recommended to include cross-ties every 10 m: small amounts of soil that are at a 90-degree angle to the bunds and prevent water run-off from catching speed along the earth bunds. This intervention is also characterized by the presence of a small ledge between the ditch and the bund in order to prevent soil from sliding back. The bunds are often stabilized with fodder grass in order to improve soil trap and water infiltration. Even though, from a technical point of view, the techniques of Fanya juu and Fanya chini are very similar, Fanya juu requires more work than Fanya chini. Over time, Fanya juu terraces can evolve in level bench terraces due to tillage or soil erosion.

Species suitability
The species most often used in drier zones are Pennisetum purpureum (Napier grass or Uganda grass) and Panicum coloratum (also known in southern Africa as “white buffalo grass”) and the harvest can be used as fodder for livestock. Fruit trees (e.g. citrus or bananas) can be planted either immediately above the embankment or below the ditch, where runoff tends to concentrate.

This intervention contributes to:

Estimation of costs and benefits of the intervention in Kenya

Establishment cost US $320/ha (including labor and equipment costs)
Labor time 90 person-days/ha
Maintenance cost US $30/ha/year (including labor costs)
Maintenance labor time 10 person-days/ha/year
Benefits Increased crop yield by 25%


Fanya juu can be particularly effective in increasing crop yields. Here is a particularly successful story about the increase in maize harvest thanks to Fanja juu in the villages of Mwembe and Bangalala in Tanzania.

In this case study, Fanya juu has been used together with soil conservation practices to alleviate  water-logging and soil degradation problems in north-western Ethiopia.

Another cost-benefit analysis of the implementation of Fanya juu in Kenya can be found here.

Here is also an example from WOCAT illustrating the combination of Fanya juu with Napier grass strips in Kenya.

A very good step-by-step is provided by Justdiggit; you can find it here.

Additional information


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Land use