There’s more to preventing soil erosion than just planting a cover crop. Even the kind of animal in the field can add to run-off – and with drought conditions worsening, a West Virginia University graduate student’s research is designed to help farmers make better decisions.
“In grasslands and pastures, people tend to think that run-off does not occur because there’s so much vegetative cover,” said Brittany Parks, a graduate student in soil physics in the Davis College of Agriculture, Natural Resources and Design. “When you include the animal aspect to it, it can really change the dynamic of the entire system. With livestock, you produce more run-off, the soil is changing and it’s not as stable.”
Parks is from Aldie, Va., a rural area not far from West Virginia’s eastern panhandle. Although she did not grow up on a farm, she is familiar with the challenges of farming and agriculturally-based enterprises. Still, some aspects of her research have surprised her.
“When I first started this project I did not think that runoff volumes from mixed species grazing would differ much from single species grazing,” she said. “But we are seeing differences between the grazing managements.”
Cattle and sheep uproot entire plants while grazing. Sheep apply more pressure on the soil with their smaller hoofs, causing more run-off than land grazed only by cattle. Cattle grazing alone tend to leave higher sediment productions, which are good for the soil.
Knowing more about the variables that affect run-off under pastures will allow farmers to better plan for the use of their land, Parks said.
“It will help them determine if they want to put livestock on the field and which times of the year are best,” she said.
Click to hear WVU graduate student Brittany Parks describe the unique aspects of her soil erosion research and its usefulness to farmers.
The short-term effects of run-off on farms aren’t obvious or devastating, but, over decades, can have detrimental effects on soil quality, land productivity and environmental quality.
Impediments to productivity can have a significant economic impact, particularly on small family farms. According to the West Virginia Department of Agriculture, more than 90 percent of the state’s 21,000 farms are small, single-family farms.
“When you have runoff, it’s carrying away the nutrients in the soil that sustain your grasslands, which is usually a primary food source for livestock,” Parks said. Phosphorus is among the critical nutrients that run-off can deplete, causing farmers to rely on expensive fertilizer to replenish them, Parks said.
Parks’ study involves collecting run-off from 12 small plots of land at the WVU Farm in Reedsville, some of which are accessible to sheep and cattle, some just to cattle and some inaccessible to the animals. The run-off from each plot flows through plastic tubes and collects into a plastic bag, which Parks empties into bottles and analyzes back at the Soil Physics lab at Davis College. Guiding the project is Eugenia Pena-Yewtukhiw, an associate professor of soil science.
Parks began collecting samples in May, 2011 and will finish in August. After analyzing her data, she’ll present her findings to the Soil Science Society of America in October at a conference in Cincinnati.
A drought is particularly devastating, not just because farmers must use their own means of irrigation, but also because of its effects on soil quality. Long term high temperatures, like those experienced in a drought, can create a crust on the soil, which inhibits water infiltration from rainfall and creates more run-off, Parks said.
Sudden downpours, Parks said, don’t remedy the situation.
“Extreme conditions like a drought followed by sudden, hard downpours create a lot of run-off,” she said.
West Virginia’s hilly terrain increases those effects but flat fields dedicated to crops can also experience erosion. Traditional methods of crop rotation and other land management strategies can counteract the effects.
Parks’ research is part of the Pasture Beef Project. Its funding comes from a cooperative agreement between the USDA Agriculture Research Service and WVU Research Corp.
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