The problems

 

Across large areas of Malawi, under the few inches of topsoil there is a heavily compacted layer of rock-hard earth.  This is largely the result of long-term use of tilling hoes, human and animal footfall, and other traditional agricultural practices.

Plant roots cannot generally penetrate through this hard layer. Nor can air or water, which are necessary for the healthy living soils that support good agriculture. Water cannot percolate into the ground where it could be stored long after the rains have stopped, and instead it runs off the surface, taking much of the healthy topsoil with it. This can result in devastating soil erosion, and the destruction of soil fertility over the years.

Other traditional farming practices in Malawi often exacerbate the problems. For example, dry maize stalks are often burned after the harvest, losing valuable organic matter and leaving the soil bare, which makes it vulnerable to rain damage and water evaporation.  The traditional “ridge and furrow” method fails to combat compaction, and a network of footpaths (pictured) can become watercourses and soil-eroded gulleys. 

Some farmers’ fields in Malawi are simply abandoned because they are assumed to be infertile.

 

The solutions

 

The Tiyeni approach contains several simple elements, which require very little in terms of material inputs, and which have repeatedly proven their effectiveness.

Some are standard textbook recommendations for agriculture, while others have been tried and tested in combination, by Tiyeni.

 

Step 1: Break up the hard pan

 

A first vital step is to use a pickaxe to break up the compacted hard layer underground.

Breaking up the hard pan already delivers powerful and immediate benefits, allowing roots, water and air to penetrate deeply into the soil, curbing or completely stopping soil erosion and allowing deep and healthy organic soils to develop. 

Crops with deeper roots not only are generally stronger, but they can successfully combat dry spells that have become increasingly common because of climate change. The soils are also able to store much larger quantities of water, for longer.

This first vital step is key to building credibility for Tiyeni’s methods, and enthusiasm for farmers.  To this credible “horse” we then harness further essential practices.

 


    Step 2: Create the Deep Beds

     

    Next is the creation of the Tiyeni Deep Beds. These are designed to minimise water runoff, to maximise water retention, and to prevent a new hard compacted layer from developing under the ground allowing roots, water and air to penetrate downwards on a long-term basis.

    Careful measurement with line levels is used to create marker ridges exactly along the contour lines of the terrain, at intervals down the slope. Each ridge has a ditch running alongside it (the ridge is created with earth excavated from the ditch.) If there is a slope, the ditch is uphill of the ridge, so it serves as a dam for water after heavy rains: each ditch has closed ends, to prevent water spilling out and to encourage it to soak downwards.  The ridge is then be stabilised by planting with Vetiver Grass, a non-invasive but deep-rooted grass that stabilises the ridge, and which is widely used for this around the world.

    Between the spaced marker ridges, deep beds of soil are created, raised above the level of the surrounding terrain. These deep beds are a metre wide, enough for two rows of maize or three rows of other crops. Once created, the deep beds are never trodden on again, so preventing recompaction.

    Between each raised bed a ditch is also dug, also with closed ends and boxed at 3 or 4 metre intervals, which become a holding reservoir for water after heavy rain and allows slow percolation into the subsoil. 

     

    Step 3: The Plants

     

    The deep beds are planted with crops. The staple crop of maize is typically interplanted with beans, pumpkin, kale, soya, ground nuts and other local crops.  

    These nitrogen-fixing “green manure crops” enhance soil fertility, protect from direct rainfall damage, and create shade which keeps the soil cooler and damper, reducing evaporation. Interplanting can help with pests and diseases, while consecutive cropping lengthens the cropping season and increases food variety leading to better nutrition. Deep bed farming potentially increases the yields of all these complementary crops.

    As the plants grow, weeds are cut or pulled up and laid on the surface as mulch, alongside crop residues, chopped Vetiver grass and other agro forestry residues. This also reduces evaporation and cools the soil adding additional organic content. Weeding is lighter work than digging, and whole families can help. The dead roots of cut weeds help the soil to breathe and microorganisms carry carbon and organic materials down into the ground.

    Meanwhile, excess foliage, crop residues, ash charcoal, maize husks and other food or household byproducts are made into compost, which can be supplemented with further additives if the soil is heavily depleted. Animal (nitrogenous) manure is added to help the composting process. The recipe for “Bokash” (pictured, source) is especially useful, since it only takes 21 days before it is ready.)

    Finally, Tiyeni likes to give pigs or goats to first-time farmers, whose progeny are then passed on to other villagers. The animal waste adds to the compost, and the programme helps bind villagers together as all are interested in the successful breeding programmes. This part of our work also helps encourage take-up of the Tiyeni methods.

     

    Step 4: The results

     

    Many Malawian farmers have achieved food security as a result of adopting Tiyeni's methods. The increased crop yields are generally repeated, year after year, and so far we have found that there is generally no need to break up the hard pan again after the first time. From then on, this becomes a form of 'no-till farming.'  

    This is a Malawian version of sustainable, effective, modern agriculture. 

    For more details about our impacts, please click here.