Material required
- 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, a hose pipe half filled with water, a bottle of water half filled with water, A-frame level. You can also 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.
Steps of implementation
- The preferred distance between the terraces depends on the slope and soil depth. The earth bunds are built by digging a trench typically 50-60 cm deep and 60 cm wide, and by relocating soil upslope 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 to prevent soil from sliding back.
- The bunds are often stabilized with fodder grass 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 into level bench terraces due to tillage or soil erosion.
Considerations for application
- 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.
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% |
Source
1. Fanya juu terraces in Kenya
Description
The Fanya juu terraces are terrace bunds in association with a ditch, along the contour or on a gentle lateral gradient. Soil is thrown on the upper side of the ditch to form the bund, which is often stabilised by planting fodder grass. The project in Kenya comprises embankments (bunds), which are constructed by digging ditches and heaping the soil on the upper sides to form the bunds. The purpose of the fanya juu is to prevent loss of soil and water, and thereby to improve conditions for plant growth. The bund created is usually stabilised with strips of grass, often napier (Pennisetum purpureum), or makarikari (Panicum coloratum var. makarikariensis) in the drier zones. These grasses serve a further purpose, namely as fodder for livestock. As a supportive and supplementary agroforestry measure, fruit or multipurpose trees may be planted immediately above the embankment (eg citrus or Grevillea robusta), or in the ditch below in drier areas (eg bananas or pawpaws), where runoff tends to concentrate.
2. Fanya juu application in Ethiopia
Description
In the northwestern highlands of Ethiopia, farmers face challenges like water-logging, soil degradation, and decreased water productivity due to traditional ploughing methods. To address these issues, a study was conducted to compare the effects of two tillage practices: winged subsoiler and traditional ploughing. The experiment, conducted over two cropping seasons, found that the winged subsoiler allowed for deeper tillage compared to traditional ploughing. Although the traditional method had slightly higher dry bulk density, the winged subsoiler showed better results overall. One significant finding was the difference in soil moisture content between the upper and lower sides of the fields under traditional ploughing. This difference wasn't observed in the winged subsoiler-treated fields. In terms of water infiltration, the winged subsoiler-treated plots showed higher rates compared to traditional ploughing. Additionally, soil evaporation was lower in the winged subsoiler-treated plots. Overall, integrating the winged subsoiler with Fanya juu, a conservation practice, proved effective for sustainable soil and water management in the region. This study highlights the importance of adopting alternative tillage practices to address soil and water challenges faced by smallholder farmers in Ethiopia's northwestern highlands.
3. Fanya juu application to increase crop yields, Tanzania
Description
In the dry areas of Same District, Tanzania, farmers are using different methods to take care of their land and water. They're doing things like making bench terraces, double digging, and a technique called Fanya juu. Researchers wanted to see how well these methods work to help farmers grow more food and keep their land healthy. They talked to farmers, looked at past studies, and went out into the fields to see what was happening. What they found was pretty cool! When farmers used these methods correctly, they grew more crops, stopped the soil from washing away, and kept more water in the ground. In the hilly areas, bench terraces and Fanya juu were especially helpful for growing crops. And in the lower areas, double-digging worked well. In some cases, maize production doubled from 8 bags to 18 bags per acre after farmers started using double-digging. Overall, the study showed that these soil and water conservation methods make a big difference in how much food farmers can grow. They're not just good for the land—they also help make life better for the people who live there. The researchers think these methods could help farmers in other dry areas too.
Guide
A very good step-by-step is provided by Justdiggit; you can find it here.
Video
Watch this amazing video from Justdiggit to know more about Fanya juu.