By Beverly James
David Wright, an agronomy professor and University of Florida Institute of Food and Agricultural Sciences Extension specialist, makes it his mission to get farmers to grow more grass. This will increase profits, reduce risk of disease and pests on row crops that follow, and conserve natural resources, according to the researcher.
The benefits in rotating perennial grass (sod) with row crops, Wright says, may help farmers boost profits two- to seven-fold. Currently, more farmers are adopting the practice. Funding is being provided by the Florida Water Management Districts and the Florida Department of Agriculture and Consumer Services, and through EQIP funds from National Resource Conservation Service (NRCS) Wright says.
Wright, based at the UF/IFAS North Florida Research and Education Center in Quincy, Florida, has been researching sod-based rotation for more than 16 years. Sod-based rotation involves planting a perennial grass, such as bahia, for several years, and then planting row crops such as cotton, peanut, soybean or cotton after killing out the sod.
Florida farmers who grow tobacco, watermelon and other high value crops have known for decades that rotating perennial grass into their growing schedule would yield higher profits. But, most farmers have their pastures in one part of the farm and the row crop land in another, Wright says. So, began his research along with a team of other IFAS scientists to explore the impact of sod- based rotation. What he found was astounding.
“We have found that sod-based rotated crops use 70 percent less water, and the soil is robust,” Wright explains. “There has been an increase in peanut yields by 25 to 40 percent, and a 30 to 40 percent increase in the total root mass of cotton and peanuts, making the crops less stressed under drought conditions. Also, we have seen a dramatic drop in fertilizer needs for following crops if livestock are grazed on the perennial grass or over-seeded winter annuals.”
In addition, there are many soil benefits from sod-based rotation, Wright says.
“Research shows that perennial grass reduces pest populations and diseases. Also, since two-thirds of the root mass of bahia and other perennial grasses is below ground, the grass leaves a lot of organic matter in the soil,” Wright explains. “The extra carbon or organic matter increases soil structure, which increases the water and nutrient holding capacity of the soil. It also enhances the microbial populations with an increase in indicator enzymes for carbon, nitrogen, sulfur and phosphorus cycling.”
Wright recommends that Florida farmers plant bahia grass for two years before rotating to peanut for a year, followed by cotton the next year, and then returning to grass. Winter annuals can be planted into the bahiagrass in the fall and grazed as well as being planted after cotton and peanut.
Cattle grazing gives a positive impact to the following summer crops with increased rooting while leaving double the amount of potassium and nitrogen in the root zone from recycled nutrients from the manure.
While the benefits of sod-based rotation are plentiful, farmers should be aware of potential problems, Wright says.
“Bahia grass produces lots of residue that can make planting peanuts difficult,” he says. “I suggest using an herbicide to kill the bahia in the fall of two year old bahiagrass and overseeding this with oats and rye, thereby giving the residue time to decompose before it’s time to plant peanuts in the spring.” Although the system is more complicated than a single crop being grown each year, the benefits far outweigh the extra management required.
Source:ufl.edu