Farm Horizons, August 2014
Row crops are susceptible to soil erosion
By Tara Mathews
Erosion from excessive rain this spring is causing problems for crop farmers.
About 75 percent of our annual rainfall was received before July, according to Urban Conservation Specialist Daniel Nadeau of Wright Soil and Water Conservation District (WSWCD).
“I’m sick of erosion,” Harlan Anderson of Cokato said. “I’ve been farming for 45 years, and this year is the worst I have ever seen.”
Anderson traveled the Wright County countryside with Nadeau to observe erosion in area fields.
“Erosion is something we underestimate,” Anderson commented.
The equipment currently used by crop farmers is larger and more invasive than in the past.
Farming has become too intense, according to WSWCD Office Manager Kerry Saxton.
“The large equipment used nowadays pulverizes the soil and makes it like flour,” Anderson commented. “Pour some flour on your sidewalk, and put your garden hose on it if you want to see how fast the soil can wash away.”
Row crops are a major culprit of increased soil erosion, according to Anderson.
“Corn is the most destructive crop, and it’s worth more money, so it’s a popular crop,” he noted. “We can make a living and be conservation minded.”
Anderson suggests planting more oats, wheat, and grains to prevent further erosion.
Problems with erosion
Erosion is the result of an accumulation of many factors such as bigger equipment, lack of close sewn crops in many rotations (corn and soybeans), intensive tillage, less conservation practices on the landscape such as waterways, and general lack of soil health.
Erosion causes gullies in fields, washes away top soil, and causes excessive amounts of nutrients in lakes.
“When the soil is washed away from the field, it finds its way to lakes and rivers, fertilizer and all,” Saxton stated. “It heavily affects recreation and can be dangerous to animals drinking the water.”
The fertilizer works the same for plants in the lake as in the field.
It accelerates growth, causing more algae, weeds, and other invasive plants.
On the other hand, pesticides can kill off necessary plants that provide oxygen in the water. When oxygen is stripped from the water, game fish will die, and species that can tolerate harsh conditions, such as catfish or carp, will flourish.
Soil washing away from the fields not only wastes money spent on fertilizer and seed it can also affect crop production.
Drown-out spots do not produce, some plants will have a lack of fertile soil, and gullies can make harvesting or planting difficult, or cause equipment to get stuck.
WSWCD has programs available to help crop farmers build dikes, basins, and waterways, which help prevent erosion.
The programs provide funding from state or federal programs, and technical or engineering assistance.
Funding options include:
• state cost share;
• federal cost share through the Environmental Quality Incentive Program (EQIP);
• low-interest loans; and
• a clean water fund.
“Some farmers don’t want funding, they just want help planning and engineering the systems,” Saxton noted.
Those farmers are given all the knowledge assistance needed to improve their erosion problem for free, according to Saxton.
“We will bend over backwards to make them a high priority, and we can because we don’t have all the waiting time as we do with funding,” Saxton stated.
Erosion control practices - basins/terraces
There are a few different types of erosion control structures that can be installed. The type installed largely depends on the topography of the land, the equipment the farmer uses, and the farmer’s preference.
A terrace is an embankment constructed perpendicular to a slope that can provide a barrier for water flowing down the slope. Terraces are often built to follow the curvature of the land.
They reduce erosion by reducing the slope length and thereby reducing water runoff velocity.
Excess water collected by terraces will drain either through a buried underground pipe system such as tile, or through grassed waterways.
Broad-base basins are largely popular because it is still possible to farm one or both sides of the basin.
Narrow-base basins are established to grass, have a steep slope, and are primarily used because of large equipment use. These basins only consume a small footprint in the cropfield, and are spaced to allow for even equipment passes.
“Basins protect the soil, protect the water, help production, and make the land easier on equipment,” Saxton noted.
Basins provide immediate benefits, and gullies are healed when a basin is installed.
An average basin costs about $10,000. The WSWCD and National Resource Conservation Service (NRCS) have programs available that will cover nearly 75 percent of the cost.
Erosion structures are helpful, but there needs to be a holistic approach to each field, according to Wright County NRCS District Conservationist Julie Reberg.
“Building soil structure and managing for microbes in the subsurface will help create a healthy soil that can withstand heavy rain events. A healthier soil will have structure and macro-pores that allow water to infiltrate faster, reducing runoff and ponding/flooding considerably,” she noted.
In addition, Reberg mentioned “healthier soils also require fewer inputs of nutrients.”
The WSWCD and NRCS are available to help local units of government and landowners protect natural resources.
What can be done?
Preventing soil erosion starts with having better soil health: disturbing the soil as little as possible, keeping the soil surface covered with residue year-round, planting of cover crops, reduced tillage, and expansion of rotation, according to Nadeau.
Dean Terning of Cokato has been participating in soil erosion prevention programs for 25 years, he said.
“Years like this accent the problem,” Terning noted.
He has eight different farms that have basins installed, and is working with WSWCD on a fall 2015 project.
“You have to be thinking about a year in advance,” Terning stated.
There may be a need for more than one terrace per farm, depending on the location.
Terning has a farm in Stockholm Township that has five basins, a farm in Cokato that has three, a farm east of Montrose that has three, and a farm east of Winsted that has four.
“The basins don’t make much of a footprint, but we do have to farm around them,” Terning commented.
The average basin consumes about four-tenths of an acre, he added.
As part of the program, WSWCD also does “spot checks” on fields that have dikes installed, which consists of testing the field for residue on top to make sure it’s at an appropriate level.
“I would recommend crop farmers get in contact with WSWCD and find out what they can do,” Terning said. “About 50 to 60 percent of my cost was covered by state or federal funded programs through WSWCD.”
A good way to prevent erosion, especially in fields with hills, is to avoid monoculture cropping, according to Saxton.
Monoculture cropping is rotating between two crops, usually row crops, such as corn.
“Flat or gently rolling land can tolerate the monoculture cropping,” Saxton noted. “But if there is any kind of hillside, the soil will wash away.”
Saxton recommends changing to a five-year cycle, such as two to three years of hay, a nurse crop for one year, then a row crop.