No-tillage or reduced-tillage farming involves growing crops without ploughing or reducing the use of machinery in preparing fields for planting. Excessive tillage can have major impacts on soils and the environment including loss of organic matter and soil organisms, increased soil erosion and pesticide runoff, reduced soil fertility, loss of soil structure, etc. Thus, implementing no- or reduced-tillage can help farmers in conserving soil quality and in many cases, increase crop production.
In implementing no-tillage processes, land is not or is minimally disturbed and crop residues are normally left on the soil surface with minimal use of implements. Reduced tillage practices include technological changes such as using more efficient ploughing tools and/or implementing strip-till, zone-till or ridge-till processes. Most reduced tillage systems are implemented in conjunction with cover crops and mulches to protect soil structure. Tilling by hand or animal means are considered reduced tillage methods.
The adoption of no or reduced tillage practices reduces the amount of fossil fuels consumed by farmers and increases carbon sequestration as soil carbon is not exposed or released in the atmosphere and is thus a climate smart practice.
Switching to no-till or reduced tillage should be planned at least a year in advance so preparations can be made necessary implements can be obtained. Implements should match farm labour availability. You will also need to decide if no till or reduced tillage methods are appropriate based on farm area and desired crops, and start with a small area to determine feasibility. Cereal and legume crops are suitable for no tillage while vegetables and other crops often require some tillage – i.e. reduced tillage.
There are two forms of no-tillage, conventional and organic. Conventional no-tillage includes the application of herbicides to manage weeds, prior to and after planting. Organic no-tillage does not incorporate the use of herbicides, but includes other methods for controlling weeds, including cover crops, crop rotation and free-range livestock. Organic no-tillage is more suitable as it assists mitigate any climate change impacts on the farm.
No till
- Step 1: Prepare fields using conventional (herbicide application) or organic processes include cover crop (Technical Brief 15) and crop rotation (Technical Brief 09).
- Step 2: Test soils – aiming to balance nutrient and pH levels. In the case of acidic soils, add small amounts of lime each year.
- Step 3: Avoid soils with bad drainage, as they become water-logged.
- Step 4: Level the soil surface, removing uneven areas to assist even seed planting.
- Step 5: Eliminate soil compaction.
Reduced Till
- Step 1: This approach is similar to regular tillage, but with significantly less disturbance of the soil. Tilling is only done where needed, and the rest of the soil is undisturbed.
- Step 2: Strip-tillage or zone-tillage involves tilling and seeding in 15 cm strips leaving areas in-between undisturbed.
- Step 3: Ridge-tillage involves preparing ridges post-harvest and letting them settle over time to be planted the next seeding period; with ridges not more than 60 cm apart.
More information of each of these specific practices should be sought prior to implementation.
Crop rotation is a complimentary farming method when practicing no-tillage, as it promotes maximum biomass levels for permanent mulch cover, while controlling weeds (with pre- and post-emergent herbicides), pests, and diseases, as well as improving soil nutrition and fertility.
- African Conservation Tillage Network, 2013. No Tillage Systems.
- CGIAR, 2014. Limited potential of no-till agriculture for climate change mitigation. Montpellier, France.
- The Food and Agriculture Organisation, 2001. Zero tillage development in tropical Brazil. Rome, Italy.
- Cornell University, 2013. Zone/Strip Tillage. Agronomy Face Sheet Series. Fact Sheet 79.
- Bucholz, D., Palm, E., Thomas, G., and Pfost, D., 1993. No-Till Planting Systems. Extension University of Missouri.
Benefits
- Increased soil fertility, organic matter and soil structure, and beneficial organisms (earthworms, etc).
- Reduced compaction of soils.
- Prevention of soil erosion.
- Reduction in fossil fuel consumption.
- Increased soil carbon sequestration.
Drawbacks
- A positive response can be delayed for up to three years.
- Effective weed management may require the application of herbicides.
- Possible decreases in crop productivity if not carried out effectively.
