Soil erosion is a commonly occurring process that affects our entire planet. It can occur slowly or at an alarming rate based on a variety of factors. In the agricultural industry, from hobby gardens to commercial growers, erosion wears away a field’s topsoil naturally and by farming activities like tillage. Let’s discuss tillage, why it’s a concern, and its effects on erosion so you can practice conservation tillage on your farm.
What Is Tillage Erosion?
Tillage erosion involves three distinct actions. It starts with soil detachment by the use of a tool, such as a shovel, rear-tine tiller, or a chisel plow. The soil is then redistributed through movement, often by natural forces like wind. Finally, it gets deposited somewhere else.
Tilling is also a significant delivery mechanism for water erosion. The newly exposed subsoil is highly susceptible to the damaging forces of rain. Because tillage moves the dirt to low spots where surface water concentrates, it causes significant soil loss on upper-slope positions, while resulting in unwanted accumulation in the field’s lowest areas.
Topsoil is high in organic matter and home to many forms of life. The loss of this layer of soil to erosion will reduce crop yields and land value, and all that dirt may end up as sediment in nearby streams, wetlands, and lakes.
In many cases, tillage erosion can cause more damage than natural forces, as it has the highest potential for the unnatural movement of soil. Several factors control the rate and magnitude of soil erosion by tillage. Let’s review those factors now.
Factors That Control Tillage Erosion
Four main elements control tillage erosion. They include:
1. Type of Tillage Equipment
There is a large variety of equipment on the market that’s intended to till the soil, from something as simple as a rake to large pieces of industrial machinery. Tillage equipment that performs lift and carry maneuvers ultimately move more dirt.
On the other hand, using implements that do not move large amounts of soil will help minimize the effects of tillage erosion. You can adjust a chisel plow to till deep or shallow, and it doesn’t invert the soil profile. On the other hand, a conventional moldboard plow’s large curved bottom blades slice through the top layers of soil and thoroughly rework its composition.
Look at your tilling implement and determine which direction your plow or discs are throwing the soil, either up- or downhill. Typically, if more earth is moved down-slope while tilling, you could be causing more tillage erosion.
3. Speed and Depth
How fast and how deep your farming equipment works also influences the effects of tillage erosion. The more soil that’s disturbed with deep tillage, combined with speed that moves earth further, will trigger an increased loss of topsoil.
4. Number of Passes
Reducing the number of passes your tillage equipment makes across your fields minimizes the movement and potential loss of soil. This practice also leaves more crop residue on your field’s surface and soil aggregates underground. This ecosystem provides pore space for water retention and room for roots to exchange air. Numerous passes make soil consistently unstable and unable to resist water and wind erosion.
Effects of Tillage Erosion
Because tillage erosion disturbs the soil, it dramatically impacts crop growth and yield. Seeds planted on shoulder slopes suffer from poor soil structure and loss of organic matter, causing plants to exhibit stunted growth. Without nutrient-rich earth, vegetables are more susceptible to stress and can’t thrive under adverse conditions.
In extreme cases, tillage erosion disturbs the ecosystem’s delicate subsurface soil. When this deep earth is on the move, it can quickly bury a fertile field’s productive topsoil in low-lying areas.
This challenging condition further impacts crop development and yield. One study of a tillage-eroded field demonstrated that just a 2-meter loss of soil on an up-slope yielded 40 percent less corn during that year’s harvest.
What Is Conservation Tillage?
The overall goal of conservation tillage is to safeguard a farmer’s soil and reduce erosion. By adopting necessary soil preservation measures, as well as progressive land management, tillage, and cropping practices, you can solve the soil erosion problem on your farm.
Contemporary conservation tillage practices protect the soil’s surface and allow water to infiltrate the earth instead of running off. Scientist group these practices into three methods: no-till, ridge-till, and mulch-till.
With the no-till method, you’ll leave the soil relatively undisturbed from harvest to planting. Use an in-row chisel or rototiller to create a narrow, 6-inch wide seedbed. Plant your crop and follow with a press-wheel to provide firm soil-seed contact.
Ridge-tilling works best when your fields are nearly level and offer poorly drained soils. By using sweeps, disk openers or row cleaners to prepare your beds, the ridges speed up the drainage. Planting on the contour significantly reduce soil loss and helps the soil to warm up quickly in springtime.
This method also leaves plant residue on the soil’s surface between rows, providing the earth with a much-needed nutrient injection. However, the land is left to rest, undisturbed from harvest to planting.
Mulch-till uses chisel plows, disks, and sweeps to till the soil before planting, leaving the ground rough and cloddy. This type of tillage does not invert the soil, and its numerous blades affect the amount of residue cover left on the soil’s surface.
Fall chiseling should be done to a depth of 8 to 10 inches, while in the spring set your chisel to no deeper than 6 inches. Choose shallow disking for seedbed preparation.
No one system is best for every garden or field, and often crop rotations or changes in your tillage practices are not enough to control your erosion troubles. A combination of approaches is often necessary, or in extreme cases where concentrated runoff occurs, it’s essential to include structural controls such as water and sediment basins.
Soil erosion is a common concern for many farmers. Thankfully, the agricultural industry is making significant progress in dealing with erosion problems with conservation tilling.