Primrose Creations | Conservation Tilling
To till or not to till? The answer could very well be both. While traditional tilling has been shown to more destructive than beneficial, conservation tillage may actually have earned a respective position in your tool bag.
Why is no-till so beneficial?
When a field isn’t tilled, the dead growth and cover crops (known as residue) are left on top of the soil. When the residue is evenly spread, it increases water infiltration and reduces moisture evaporation. Large amounts of residue can help poor draining soil, such as clay, hold onto moisture that prevents soil warming and drying in the spring, delaying germination of seeds until the optimal time. With climate changing, proper soil maintenance will be essential for optimal crop growth. Beyond water retention, no-till methods of farming reduce or eliminate erosion due to wind and water. Economically, no-till farming systems reduce fuel and labor costs3.
The downside of traditional tilling
In moist soils, particularly those with higher clay content, a traditional blade plow causes soil to smear and compact below the blade. Above a plow blade, the soil loses its structure and is left vulnerable to compaction by rainfall2. In traditional tilling operations, the soil is overturned to a depth between 8 and 12 inches. Such a deep operation displaces in-tact weeds and allows the contained roots to re-root. A shallower displacement can result in the breakup of weeds and leaves the organic matter in place to decompose into the soil.
Conservation tillage is a bridge for farms
On slopes that are steeper than can normally be planted, no-till fields have consistently shown minimal topsoil loss after downpours of several inches per hour2. That same residual cover also makes the no-till field less susceptible to the effects of wind erosion. Soil moisture levels can be improved enough that it can be more than 10% higher in late July in a field using conservation tillage as compared to a traditionally tilled field2. Conservation tillage systems have a positive impact on soil health and productivity under extreme conditions such as excessive rain or drought. These systems can impact soil health over time by improving soil infiltration, organic matter, microbial diversity, and soil structure. When using traditional tillage or machinery, the soil becomes compact and unable to perform optimally. When those practices have stopped, the soil will become less compact over a few years’ time2.
Types of conservation tillage
The Conservation Technology Information Center’s definition of no-till includes strip-till, provided less than one-third of the total row area is tilled4.
A strip-tillage operation is preferred since this tillage operation removes residue from row tops, allowing sunlight to warm the soil4. The remaining residue keeps moisture in the surrounding soil and adds to the overall organic composition. Planting with strip-till occurs in the residue-free areas.
The blade plow or sweep plow cuts weeds at the roots and leaves most of the residue at the surface with minimum disturbance of the soil surface5. This type of tillage should be completed at a shallow depth when the soil is dry, such as a hot day. This causes small weeds to be lifted so they dry out while larger weeds are cut off from their root system5.
Soil conditions dictate what form of tillage is best for any field and can vary between rather small areas. It is important to consider natural drainage, topsoil depth, soil slope, organic matter, and soil texture when determining which tillage method to use1. These factors have an impact on how each method of tillage affects soil health, productivity, and water quality1. While no-till may still be the most beneficial, conservation tillage build the bridge to get there.
References
1. Al-Kaisi, M. (2018, October 30). Let’s talk no-till. Retrieved from https://crops.extension.iastate.edu/cropnews/2018/10/lets-talk-no-till
2. No-till farming pros and cons | Mother Earth news. (1984, June). Retrieved from https://www.motherearthnews.com/homesteading-and-livestock/no-till-farming-zmaz84zloeck
3. No-till. (2018, December 4). Retrieved from https://cropwatch.unl.edu/tillage/notill
4. Strip-till (2018, December 4). Retrieved from https://cropwatch.unl.edu/tillage/striptill
5. Stubble mulch. (2018, December 4). Retrieved from https://cropwatch.unl.edu/tillage/stubble
