If you have been farming for years, it may be difficult to break from the tradition of plowing your fields and feeding crop residue like maize stalks or wheat stubble to livestock rather than leaving it in place. But climate change is forcing many to rethink their traditional farming methods, and the practice of conservation tillage (also called conservation agriculture) has been shown to reduce soil erosion and retain moisture for plant roots. It also saves labor!
Conservation tillage methods include no-till, strip-till, ridge-till and mulch-till.
- No-till and strip-till involve planting crops directly into residue from the previous season’s crop that hasn’t been tilled (no-till) or has been tilled only in narrow strips with the rest of the field left untilled (strip-till).
- Ridge-till involves planting row crops on permanent ridges about 12 centimeters high. The previous crop’s residue is cleared off ridges into adjacent furrows. Maintaining the ridges is essential.
- Mulch-till is a method that leaves at least 30 percent of the soil surface covered with crop residue.
The goal with all of these methods is to minimize soil disturbances. This helps to build the soil’s health and its ability to hold moisture, allowing crops to grow better during dry weather extremes. Farmers also benefit by:
- Reducing soil erosion by as much as 60 percent, depending on the tillage method and amount of residue left to shield soil from rain and wind.
- Adding healthy organic matter to soil.
- Decreasing their expenditures on fuel and planting because fewer tractor trips across the field are needed.
- Reducing potential air pollution from dust and diesel emissions.
- Reducing soil compaction that can interfere with plant growth.
Over time, conservation tillage accompanied by crop rotation and the use of cover crops has been shown to increase harvest yields, in addition to helping the soil. The U.N.’s Food and Agriculture Organization (FAO) did a case study in Tanzania that showed that by the sixth season, crop yields had increased from three bags of maize and one to two bags of beans per acre to 30 bags of maize and 10 bags of beans per acre.
Interested in learning more? Here are some practical steps from an FAO publication to get you started.