In partnership with MCC/ CFGB
SASOL Foundation has a Conservation Agriculture pilot project where we are working with 50 farmers in Mbitini/Kisasi ward, Kitui County. The selected area has potential for agricultural production, but is afflicted by declining soil quality and an inadequate water supply. Most of the soil water run-off drains away from the fields due to poor agronomic practices, and the high evaporation rate accounts for the decline in crop moisture retention. The majority of farmers in the target area have limited knowledge on conservation agriculture.
Project Approach and Prospective Outcomes
Each farmer is to have a demo plot of ½ an acre in which the three CA principles will be practiced. Farmer-to-farmer visits will also be required in order to motivate farmers to develop in the new CA practices through community based knowledge sharing.
The ultimate goal for the project is to improve food security for the first 50 farmers in the target area. SASOL plans to expand the CA project by June 2015 to include 350 farmers in Mbitini\Kisasi ward and Kitui central ward. Conservation agriculture is being promoted for its resource saving capacity including maintaining soil fertility, erosion control, reducing desertification and efficient use of scarce water resources; all of which are struggles that Kitui County faces. CA has been advocated for as having the potential for climate change mitigation by reducing vulnerability of production systems to extreme climatic conditions, and specifically in drought conditions, reducing water requirements and making better use of soil water. CA takes into consideration the long –term sustainability of agriculture, and it is SASOL’s belief that by employing CA, it will provide opportunities for farming households to improve their livelihoods.
The Principles of Conservation Agriculture:
Minimum soil disturbance
Direct seeding involves growing crops without mechanical seedbed preparation and with reduced soil disturbance. The term direct seeding is understood in CA as synonymous with no-till farming, zero tillage, no-tillage, and direct drilling. Land preparation for seeding or planting under no-tillage can be done in two ways. First is slashing or rolling the weeds, previous crop residues, or cover crops. Second is spraying herbicides for weed control, and seeding directly through the mulch. Crop residues are retained either completely or to a suitable amount to guarantee a complete soil cover, and fertilizers are either cast on the soil surface or applied during seeding.
Crop rotation /association
The rotation of crops is not only necessary to offer a diverse “diet” to the soil microorganisms, but as the roots grow to different soil depths, they are capable of exploring various soil layers for nutrients. Nutrients that have been leached from deeper layers can be “recycled” by crops in rotation. Furthermore, a diversity of crops in rotation leads to diversity in the soil. As the roots excrete various types of bacteria and fungi, plant available nutrients are left behind for the next rotation of crops. Crop rotation also has an important function in preventing the carry-over of crop-specific pests and diseases from one crop to the next. Farmers practice crop rotation through crop sequences, intercropping, relay cropping, and mixed crops.
Permanent soil cover
A permanent soil cover is important in protecting the soil against exposure to rain and sun, to provide the micro and macro organisms in the soil with a constant supply of “food”, and to alter the microclimate in the soil for optimal growth of soil organisms, including plant roots. Farmers cover the soil with the crop itself, cover crops, crop residues, and mulch.
More Info on Cover Crops
Cover crops are suitable for:
- Providing an additional source of organic matter to improve soil structure.
- Improved topsoil
- Recycling nutrients and mobilizing them in the soil profile.
- Percolation capacity of the soil
- Utilizing easily leached nutrients.
The impacts of soil cover, using crop residue /mulch:
- Improved infiltration and retention of soil moisture resulting in a reduction of crop water stress and increased availability of plant nutrients.
- Increased humus formation
- Reduction of the impact of rain drops on the soil surface.
Benefits of conservation agriculture include:
- Reduction in the formation of hardpans produced by continual ploughing.
- Protects soil from erosion through cover crops and mulch.
- Increases soil moisture, allowing for earlier planting and the reduction of drought impact.
- Restores and helps to maintain soil fertility, thereby improving crop production over the long term.
- Stabilizes yield by minimizing the vulnerability of the agro ecosystem.
- Stabilizes farm income and helps to diversify community diets through the production of a mixture of crops.
- Reduces input costs, as the expense of tilling the soil is reduced or entirely eliminated.
- Reduces labor costs, as conservation farming is less labor intensive as conventional farming.