Similar names: Alley farming, intercropping, farming with shading trees, Nalaad (Philippine)
INTRODUCTION
Alley cropping is an agroforestry technique that involves planting crops between hedgerows of trees and shrubs. Tree-crop combinations are used to solve soil erosion problems by slowing water runoff and increasing its infiltration rate. Trees also provide very effective protection for crops against strong winds, can serve as wildlife habitat, and attract pollinators. Hedgerows can be tailored to the farmer’s needs and serve as crop facilitators or as a source of fodder, food, firewood, mulching material, or as an additional source of income.
This technique can be applied on a large scale, increasing the distance between the alleys and allowing for the use of big machinery, but can also be applied on a small scale, where a hedgerow surrounding the field or farm area may be all that is possible, instead of complete alleys.
PRE-CONDITIONS FOR IMPLEMENTATION
- 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.
METHOD OF APPLICATION
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.
BENEFITS
This intervention contributes to:
COSTS
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% |
CASE STUDIES
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.
NOTE: This method works particularly well in humid and semi-humid regions but should be well planned in dry areas, as hedgerows can compete with crops for soil moisture.
METHOD OF APPLICATION
The first step is to determine which species to plant in the hedgerows and as a crop. There are different possible combinations, but it is important to keep in mind the desired function of the hedgerows and the suitability of environmental conditions.
On flatlands to gentle slopes, hedgerows are usually put 2 to 6 m apart. On steeper slopes, the hedgerows should be about 2m apart and placed along the contour of the land (perpendicular to the slope). The distance between each tree should be 5 to 10 cm apart to be able to capture the eroded material. On such steep slopes it is possible to plant temporary stakes in the ground near the seedlings to form barriers that control soil erosion whilst waiting for the trees to have grown enough.
Different measures can be taken to obtain the desired effects:
- To prevent soil erosion: hedgerows should be planted perpendicular to the slope
- Shade: especially on low slopes, the orientation of hedgerows can be adjusted according to the desired amount of shade. Moreover, when they grow too tall, trees can be pruned or thinned, and the extra material can be used as mulch, fodder or fuelwood.
- Windbreak: trees should be arranged perpendicular to the wind direction
- Soil fertilisation: leguminous trees and other nitrogen fixing species should be planted to increase the amount of nitrogen in the soil
- To act as a biodiversity corridor: place the hedgerows so as to connect two nature areas (such as two forests). The hedgerows can be enriched with flowers to stimulate pollinators and have dense vegetation, to shelter small wildlife.
The most common crops grown in tree-crop systems are maize, soybean, wheat, groundnut, coffee and cacao. However, the chosen vegetation should be adapted to the environmental conditions of the area and can also be gradually adapted to best face climatic changes.
For a more detailed description of the method of application, please read this document.
SOCIO-ECONOMIC CONSIDERATIONS
Advantages
- Reduced water runoff and soil erosion
- Increased water infiltration rates
- Improved crop performance – yields?
- Increased provision of organic matter
- Minimised nitrogen leaching
- Can be combined with the use of machinery when applied on a larger scale
- Can be applied at multiple scales
- Promotion of biodiversity through…
- Diversified source of income
Conditions
- Assisted Natural Regeneration is a more effective and cheap way to grow trees, especially if you live in very dry areas.
- If you want to plant trees, before doing so, it is fundamental to make sure all the conditions essential for tree growth are present (such as a soil depth of at least 1.5 metres). If you are not sure these conditions apply to your land, ask an extension officer in your region or someone who has experience with growing trees in the area.
- If you are renting the land, make sure with the owner agrees with the presence of trees.
- Importance of weeding: in the initial stages of tree growing weeding must be done to maintain the intervention in the initial stages of tree growth.
- Tree planting can be expensive if there is no nursery available (depends on the species that want to be planted): good quality seed availability or access to a tree nursery is thus important
- This intervention requires special management; hence, an optimal selection of planted species must be made in drier areas so as to prevent competition for moisture between hedgerows and crops.
- Allelopathy between species should be considered: some species release chemical substances which have negative impacts on other plants and can inhibit their growth
- In temperate regions, the majority of trees are used for biomass production, whether in subtropics and tropics, trees are mainly used for food, fodder and crop facilitation.
CASE STUDIES
China:
Alley cropping can be used in combination with other interventions such as terracing. Click here to know more about it.
France:
Alley cropping can also be practiced with the help of machinery. Click here to know more about it.
Benin:
An example of alley cropping in dry areas can be found here.
Jamaica:
Alley cropping can result in a very effective way to slow soil erosion and increase yield. A very good example can be found here.
USEFUL LINKS
Click here for free Webinars about alley cropping.
INTRODUCTION
Alley cropping is an agroforestry technique that involves planting crops between hedgerows of trees and shrubs. Tree-crop combinations are used to solve soil erosion problems by slowing water runoff and increasing its infiltration rate. Trees also provide very effective protection for crops against strong winds, can serve as wildlife habitat, and attract pollinators. Hedgerows can be tailored to the farmer’s needs and serve as crop facilitators or as a source of fodder, food, firewood, mulching material, or as an additional source of income.
This technique can be applied on a large scale, increasing the distance between the alleys and allowing for the use of big machinery, but can also be applied on a small scale, where a hedgerow surrounding the field or farm area may be all that is possible, instead of complete alleys.
NOTE: This method works particularly well in humid and semi-humid regions but should be well planned in dry areas, as hedgerows can compete with crops for soil moisture.
Materials required
- shovel
- tubing
- manure
- seedlings