Finding a solution for Southeast growers
Furrow diking is nothing new. It was practiced by growers as early as 1915, when the first patent was issued for furrow diking equipment.
However, this tillage system of creating
Finding a solution for Southeast growers
Furrow diking is nothing new. It was practiced by growers as early as 1915, when the first patent was issued for furrow diking equipment.
However, this tillage system of creating little basins and dams to hold rain or irrigation water throughout a crop field has been the subject of intense research in the past decade for two important reasons: increased irrigation costs and the competition for dwindling water resources between agriculture and populated urban areas.
While the practice of creating ridge-like barriers to hold water and allow it to soak into nearby crop rows makes perfect sense for arid areas of the country (such as in the western United States), what about other areas that get plenty of rainfall, but experience dry spells or have sloped fields prone to water runoff or pooling?
Two scientists with the USDA ARS—Russell Nuti, research agronomist, and Clint Truman, soil scientist—aimed to find that out in their research at the ARS National Peanut Research Laboratory in Dawson, Ga. The goal was to find out if furrow diking would work in the Southeast, where water runoff for peanut, cotton and corn crops is an ongoing issue.
“In the Southeast, we do get plenty of rain to produce plenty of crops, but there are sporadic periods [of rain and drought],” said Nuti. “We wanted to see if we could capture that water and get more use out of it.”
What they found is that furrow diking is well worth the effort and produces a return on investment in the form of reduced irrigation costs.
The benefits of furrow diking
During a moderate drought, the practice saved growers an inch of irrigation water per acre. It also significantly reduced runoff and helped stop soil erosion. In the next year the study was done—a year with more severe drought conditions—the practice saved 5 inches of irrigation water.
The study was done on peanut, cotton and cornfields that were furrow diked and compared to the same crops that were grown in traditionally tilled soil.
Similar studies have been, and are still being, conducted in areas throughout the Southeast, including fields in Georgia, Mississippi, North Carolina, Alabama and Louisiana, with comparable results.
“In areas that get plenty of rainfall, furrow diking helps take better advantage [of the water] and reduces soil erosion,” says Nuti.
While Nuti would not speculate on how furrow diking would work on other crops and in other areas of the country because the research has not yet been done in those areas, he did say that growers with sloped fields would most likely get the most benefit.
“Any field that has any slope at all will have runoff in any rainfall event, or any place that has any drought period will see a benefit,” says Nuti.
Even growers who use irrigation to supplement rainfall will see a benefit, he says. “If you get enough rainfall, but not at the right time optimal for crop growth, furrow diking will help,” he says.
Of the two soil types—clay and sandy—the most runoff happens in clay soil. “So we speculate that [growers] with clay soils would get better benefits of the dikes than those in sandy soils,” says Nuti.
In drought-ridden areas, Nuti says, growers can irrigate directly into the dikes and reduce potential evaporation.
A good return on investment
The money you save on irrigation will pay for the money spent on labor and equipment costs of furrow diking, says Nuti.
Just one significant rainfall of 1 inch will give the grower an ROI. “A series of rainfalls, particularly if it causes a grower to irrigate just one less time, will pay for the [entire diking equipment and labor],” says Nuti.
According to the study, based on a rate of $12 per acre-inch to pump irrigation water and $7.50 per acre for furrow diking, “ … producers would recover 60 percent of their diking cost by saving the first acre-inch of water and 100 percent of their diking cost by saving 1.25 acre-inches of water. Water and financial savings do not include the environmental benefits of reduced natural resource consumption, runoff, soil erosion and as