Conservation tillage is a set of practices and methods of land preparation that aim towards reduced, minimum, or zero soil disturbance and retention of crop residue on the soil surface meant to reduce surface runoff, reduce surface soil temperature, and associated evaporation. These practices also help to build soil organic matter. Conservation tillage employs the use of specific tools compliant with its principles.
There are various strategies/methods for conservation tillage. Conservation tillage approaches are aimed at enhancing soil formation, organic matter content and management, zonal cultivation, and integrated pest, weed, and disease management. Each of these strategies has its interventions or practices set out to achieve the intended goals.
Conservation tillage approaches are aimed at enhancing soil formation, organic matter content and management, zonal cultivation and integrated pest, weed and disease management.
Soil Formation
Soil formation is achieved by practicing sub-soiling, which is the deep cultivation to break soil hardpans mainly created by shallow cultivation over a long period of time. Subsoiling is done by a tractor-mounted subsoiler which would dig up to 30 cm deep. Small farm sizes can also use animal-drawn chisel plows. Subsoiling makes the soil capable of supporting all crops which would initially not do well as a result of compaction under 20 cm deep. Organic matter management, on the other hand, is achieved through zero tillage- where the farmer grows crops without disturbing the soil through tillage; use of cover crops, and mulching.
Zonal Cultivation
Zonal cultivation (ZC) as a strategy of conservation tillage involves the practice where only the row area is cultivated and the rest of the land is left undisturbed. ZC is achieved through the establishment of broad beds, grass strips, ridges, and furrows. Integrated (pest, disease, weed) management, on the other hand, is achieved through crop rotation and the use of cover crops.
Why Adopt Soil Conservation Tillage?
Conservation tillage helps to retain soil moisture by regulating soil temperature, protecting topsoil from surface runoff, and enhancing soil organic matter which then increases water holding capacity. Other benefits of conservation tillage include:
• Reduces the number of field operations from an average of seven to one, translating into 8-12 hours per ha saved in tractor time (a 60-90% saving); farmers can save 36 liters of fuel per ha of land, an 80% saving over conventional wheat cultivation. This saves on the cost of production.
• Reduces water usage by about 1 million liters per ha (a saving of 20-35%). This helps to cushion your immediate environment and farm from climate change hazards.
• Improves soil structure, fertility, and biological properties. Through the increase in organic matter retention and incorporation into the soil, conservation tillage practices lead to an overall improvement in soil health through soil formation and humus addition necessary for a productive farm.
•Typically reduces the incidence of weeds, primarily due to the earlier emergence of wheat and reduced soil disturbance.
• Increases in crop yield by 8-15%. This is done by creating a better environment for the crops, i.e. deeper soils, more nutrients, higher soil moisture, water availability, and better water retention among other benefits that ensure robust plant growth.
•Reduces production costs by 10-20%. With a lower cost of land preparation, irrigation, nutrient supplementation, and pest, weed, and disease incidences, conservation tillage significantly cuts down the cost of production for farmers allowing them to save more for other investments.
Conservation tillage is one of the many ways you can farm with nature, ensuring that you have your food for the season and the soil, and the entire agroecosystem for generations.
