No-till or zero tillage agriculture is part of the practice of conservation agriculture.
It is a way of growing annual crops (from year to year) without disturbing the soil unlike traditional forms of agriculture that use tillage.
Tillage is the use of ploughs and other implements to prepare the soil for planting. Tilling the soil removes weeds and shapes the soil into rows for crop plants.
However, there are some undesirable effects of tillage. These are listed below:
- Soil compaction
- Disruption of soil microbes
- Loss of organic matter
- Soil erosion where the topsoil is washed or blown away
- Increased evaporation of water
These are negated when a no-till farming is used.
No-till has advantages as listed below:
- Reduced labour costs
- Reduced fuels costs
- Reduced machinery costs
- Reduced irrigation
- Increased yields due to higher water infiltration and storage capacity
- Less erosion
- Improvement in soil quality
- No tillage pan means roots can grow deeper
- Smaller, lighter tractors can be used which reduced compaction
There are some disadvantages with no-till farming though.
- If no-till is done incorrectly, crop yields will be reduced
- Increased use of herbicide needed to kill the weeds that ploughing would have removed
- Remaining crop residue can increase disease lying in the field
- Gullies that form increase each year without ploughing
- Specialist equipment and knowledge is needed for no-till
- Residue build up of old crop can occur if the field is incorrectly prepared
- Yields reduce in the transition time from conventional tillage to no-till
- Transition time to no till is 4-5 years
No-till farming most closely mimics the natural soil conditions compared to other methods of farming. The soil is left undisturbed apart from where the seeds are placed which preserves the soil. Soil conservation is vital for its ability to grow food for an ever expanding population.
Written by Fiona Johnson