Morris Musango from Kathulumbi village in Kalawa removes soil from a terrace dug to catch road run-offs.
With climate change, there are calls for farmers to embrace climate-smart strategies that conserve soil moisture and guarantee high yields. One such method is no-tillage.
This is the planting of crops into soil that has remained untilled after the harvest of the previous crop.
The soil is a complex ecosystem, packed with very diverse life. It consists of about 50 billion microbes in one tablespoon of soil.
- What needs to be done to address Africa climate change concerns, challenges
- KGBS partners with Nairobi County to tackle climate change
- Going green: Kenchic's solar plant to save money and fight climate change
- Project on climate resilience targeting youth, women launched
Digging and turning over the soil exposes a very delicate ecosystem to the air which dries it out, and to the ultraviolet rays of the sun, which sterilise the soil killing the soil organisms.
As a result, the soil loses a lot of its nutrients. It also loses organic matter, therefore, cannot retain water effectively.
Digging weaken the soil structure which causes compaction leading to the formation of hardpan and reduced water infiltration in the soil, and more surface runoff increasing soil erosion. The benefits of no digging method:
Minimal disruption to the soil
Where you leave the soil unturned, beneficial organisms can thrive in their natural undisturbed environment. This allows for a balance between prey and predator species.
When it comes time to plant your garden seeds, all you need to do is pull back the mulch and use a rudimentary tool, such as a stick, to draw a line directly on the soil. Fill the small trench with seeds and patiently wait for them to emerge. There is absolutely no need to go any deeper, the worms are far better diggers than we are – if you feed them, they will help to feed you.
Digging the soil, then compacting it by the tractors, ox-plough or feet destroys the soil structure. The compaction prevents water and air to penetrate the plant roots.
Reduced incidences of weeds
The lack of bare soil in a no-dig garden prevents both perennial weeds and seeds of annuals from germinating.
With layers of mulch covering nearly your entire garden, weed cover will be much less than in a conventional garden. Of course, there will always be some amount of weeds, brought in via compost, or simply by blowing in.
With each season, the weed cover will gradually decrease, and they only need removing by hand. Pull a few weeds every time you go out to harvest and your garden will be weed-free daily.
Enhanced micro-organism
The minimum soil disturbance ensures that the small organism in the soil thrive and multiply. Their activities of the breakdown of materials in the soil are enhanced.
When you stop digging and let the soil rest, year after year it will become stronger and more fertile.
On the other hand, when the soil is plowed deeper and turned, there is a loss of beneficial life. Disturbing the soil actually decreases the amount of worms. As you continuously add mulch and compost to your no-dig garden, you are giving the worms exactly what they need, and they will help aerate the soil in return. When the remains of the previous crops are left to rot and mix with soil, the nutrients they had accumulated are returned to the soil.
Water retention
No digging method retains and increases the amount of water in the soil. The no-till method will give your garden the ability to soak up and retain soil moisture, at the same time allowing the excess water to drain away.
The method reduces soil erosion. The minimum or no soil disturbance strengthens soil structure which resists the movement of soil by rainwater.
Higher yields and faster crop maturity
The crops are planted immediately the rains are on which means they germinate and mature faster compared to systems where ploughing is done after the rains. The extra moisture the soil had also helped.
As you start out with layering your compost and organic matter, it will take some months for those materials to break down to the stage of providing nutrients for your crop for higher yields.
