BLACKVILLE – Tucked away in Barnwell County is a 2,400-acre facility that leads the region in crop and technology research dedicated to helping South Carolina farmers grow bountiful crops to meet food and fiber needs of today’s population.
The facility is Clemson’s Edisto Research and Education Center (REC). Research is conducted to improve the ways farmers and livestock owners can earn top dollar for their crops and animals.
“We have an excellent group of researchers and staff who work hard every day to determine what South Carolina farmers can do to lower their costs while, at the same time, maximizing yields,” said Chris Ray, Edisto REC director. “High input costs, increased demands on water and low prices on agricultural commodities force us to look at more efficient ways of doing business.”
Precision agriculture, a farming management concept based on observing, measuring and responding to inter- and intra-field variability in crops, is a major focus for Edisto REC researchers. One example is research conducted by Joe Maja, a research sensor engineer, who is using his knowledge to determine which technologies and devices are best to use for precision agriculture.
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Maja also uses unmanned aerial vehicles (UAVs), fit with “intelligent agri-tronics devices,” sensor-based technologies, to monitor crop health and gather data to let growers know precisely when and where to water, fertilize or spray crops. Most recently, Maja is working on plant inventory using drones. This work is funded by the Horticultural Research Institute. Another funded project from Cotton Inc. involved the use of an autonomous mobile platform for weeding and harvesting.
“All these technologies being developed are particularly important not only in South Carolina but nationally as we share common crops and issues," he said.
Maja also has worked with Clemson University Research Foundation in applying for a provisionary patent for a temperature compensated soil moisture sensor.
Jose Payero, an irrigation specialist, focuses on developing newer and less costly irrigation technologies for farmers. He explores ways farms can become more efficient and more resilient to climate risks, including using moisture sensors and weather-based tools to monitor crops.
Payero recently developed a new affordable system to collect and transmit soil moisture data using radio communication and/or a cellular network. He is now conducting a project funded by United States Department of Agriculture Natural Resources Conservation Service to demonstrate and promote the adoption of this system among South Carolina farmers.
“Measuring soil moisture is one way to determine when crops need irrigation and how much irrigation water to apply,” Payero said. “This could save water, use less energy, reduce pumping costs, increase yields and help protect the environment from excess irrigation. Excess irrigation increases production costs and can have negative environmental effects such as runoff, waterlogging, or leaching of soil nutrients and other chemicals that eventually can contaminate water sources and reduce yields.”
Payero also is developing cost-effective systems that use wireless sensor networks to automate irrigation based on real-time and site-specific soil moisture information. He measures the impact of changes in weather and crop conditions on the daily water use of crops. This information is used to develop online decision support systems so farmers can plan and schedule irrigations based on weather data.
Gilbert Miller, a vegetable specialist at Edisto, also studies irrigation. One project involves sensor-drip irrigation that uses soil moisture sensors to determine soil moisture content in the root zones of plants.
“When soil moisture reaches a designated, or trigger, deficiency the sensors will trigger an irrigation cycle,” Miller said. “This is a proven method of conserving water and nutrients, while fully meeting the plants’ requirements for water. This technology is still relatively new. It’s not grower-friendly now, but will be in the future.”
In addition to using soil moisture sensors, knowing crop water use by crop growth stage is important to ensure crops have enough water to be productive. Soil tension and volumetric are the two most common types of soil moisture sensors used for scheduling irrigation.
Michael Plumblee, a precision agriculture specialist who also is an Agronomic Crops Team and Water Resources Team member, said depending on which type of sensor a producer may be using, threshold values or threshold units may vary.
Typical recommendations place threshold values between 25% and 50% maximum allowable depletion, which means 25% to 50% of water available to plants in the soil is allowed to deplete before recharging with irrigation.
Kendall Kirk, an agricultural engineer at Edisto REC, has developed free software to help farmers track soil sampling in their fields. The software pairs with an inexpensive global positioning system and a laptop computer to pinpoint exactly where soil samples are taken as they are taken. This ensures growers are taking adequate samples throughout field management zones, which are areas of field with common soil characteristics that will likely require similar nutrients. Collected samples then can be sent to local Clemson Cooperative Extension Service offices for testing at Clemson’s Agricultural Service Laboratory.
Kirk is involved in a number of other software development efforts, including irrigation evaluation software, image analysis software, and several web apps. But software is not all his group does; his team also evaluates and develops technologies for harvest machinery, having been awarded four patents for precision agriculture technologies since he began work at Edisto REC.
Protecting the environment
Helping farmers reduce input costs while protecting the environment is another research focus at the Edisto REC. Payero and Michael Marshall, weed specialist, are looking at benefits associated with using cover crops such as weed prevention and soil and water conservation. They have developed equipment to automatically measure runoff and collect water samples to quantify the impacts of cover crops on soil erosion, runoff and runoff water quality.
In another study, Payero, Marshall, Maja and graduate student Stewart Bell are investigating remote sensing to automate site-specific nitrogen application through using lateral move irrigation.
Hehe Wang is a plant bacteriologist and pathologist, as well as a member of the Clemson Peach Team, who is expanding her research at the REC to promote sustainable agriculture by studying epidemiology, ecology and genetics of bacterial pathogens in numerous crop production systems. Her program involves developing management strategies to reduce inoculum sources and minimize disease development, as well as studying interactions between different plant pathogens and exploring beneficial bacteria in plant health management.
“Bacterial diseases have become an increasingly major concern for South Carolina growers,” Wang said. “Bacterial spot of peach can cause annual losses of more than $10 million when high disease pressure is present. Bacterial canker is another bacterial disease that affects about 2% of peach trees and results in annual losses of approximately $1 million. Bacterial leaf blight of brassica greens could cause annual losses of more than 30% marketable yield and nearly $2 million.”
Wang also is working on a project using beneficial bacteria on managing peanut late leaf spot and white mold, the top two disease concerns of South Carolina peanut growers.
Other research conducted at the Edisto REC focuses on determining how to optimize nutrient application rates so that farmers will know how much fertilizer and/or nutrients their crops require. This research is conducted by Bhupinder Farmaha, an assistant professor and nutrient management specialist, who also is involved in a USDA-NRCS study to determine how cover crops and conservation tillage contribute to soil health.
“In the past century, U.S. agriculture has seen a big shift from highly diversified low-input agricultural production systems to highly specialized systems that dramatically increase yields with intensive use of synthetic fertilizers,” Farmaha said. “In order to fulfill our commitment to a sustainable future and ensure food security for a growing global population, we need to restore and enhance soil health that supports agricultural production.”
Crops and cows
Apart from his irrigation research, Miller is known far and wide for his studies on watermelons. Currently, he is growing and evaluating different types of watermelon and pumpkin in yearly variety trials.
“We’re testing these varieties because growers need to know how these varieties perform in our geographic area,” Miller said.
Peanut research also is conducted at the Edisto REC. Dan Anco, Clemson’s peanut specialist, conducts research supported by the South Carolina Peanut Board and the National Peanut Board. Anco’s work involves evaluating varieties for performance under South Carolina conditions and improving efficient management of economically important diseases.
“New varieties are constantly being developed,” Anco said. “We are evaluating varieties for performance so producers can make informed decisions regarding variety selection and choice of management practices to improve cost-effective production under different conditions. Our research efforts against diseases use a multi-pronged approach to target our practices, alternate and combine effective chemistries for resistance stewardship and implement information-based decision making for optimal and economical management.”
Insect pests and weeds affect every crop. Jeremy Greene, entomologist, and Marshall are focusing on improving recommendations on how to manage these pests.
Greene’s program focuses on management strategies for insect pests in cotton and soybeans. He promotes the integrated pest management (IPM) approach, using chemical, biological, cultural and other control tactics in battling insects. Greene also has produced two free mobile apps that growers can use to calibrate and mix sprayers. These apps are available in both Android and iOS platforms and are called “Calibrate My Sprayer” and “Mix My Sprayer” on the app stores, or at http://www.clemson.edu/extension/mobile-apps/
Marshall’s research program involves tackling herbicide-resistant weeds in cotton, peanuts, soybeans and corn.
“Herbicide-resistant weeds, most notably Palmer amaranth, are impacting the sustainability of South Carolina row crop producers,” Marshall said. “We have many on-going trials looking for practical solutions to these challenges. For example, winter cover crops can enhance control of Palmer amaranth by producing a mulch layer that shades out the soil surface during the early part of the season.
“Other research includes evaluating herbicide programs for weed control. Herbicides that have soil activity are key in the battle against resistant weeds because they add additional modes-of-action and reduce the likelihood of developing new resistance. My program provides chemical and cultural solutions to preserve crop yields and sustainability of producers’ operations.”
John Mueller, a nematologist, focuses on identifying cost-efficient nematode management strategies that combine crop rotations, resistant varieties and judicious use of nematicides. Of special interest right now are the recently released cotton varieties that have been bred to be resistant to Southern root-knot nematode. Projects underway are evaluating yield potential in fields with high populations of Southern root-knot, as well as Columbia lance and lesion nematodes.
Mueller is also surveying South Carolina agricultural fields for Meloidogyne enterolobii (M.e.), and invasive root-knot nematode. This damaging nematode was recently found in Darlington County. He is part of a multistate effort to develop crops resistant to M.e. root-knot nematode as well as integrated management programs involving rotations and nematicides.
“Nematodes are one of the hard to manage pests that can have dramatic effects on crop growth and yield, especially cotton and soybean,” Mueller said. “My research has shown damaging levels of several nematode species are present in over 50% of South Carolina cotton and soybean fields.”
In addition to studying crops, Edisto researchers also are studying cattle. Scott Pratt, a Clemson professor of animal and veterinary sciences, conducted a beef cattle reproduction study based on the use of gender-selected semen in which he found pregnancy rates using sex-sorted semen in conjunction with timed artificial insemination tended to decrease pregnancy rates by less than 10% by Day 45 of gestation.
Data Pratt has been collecting for the Edisto REC bull test is being compiled for analysis and will assess the impact of an all-forage diet on male reproductive performance.
In addition to studying crops, Edisto researchers also are studying cattle and the forages they thrive on. Earlier this year, Scott Sell, bull test and heifer development research associate and cow herd coordinator, added the Edisto Heifer Development Project to the Edisto REC’s mix of livestock and forage research and outreach.
This is a sister program to the bull test and accepts heifers from all over the Southeast to breed and evaluate them for reproductive and economic traits. The program culminates with a bred heifer sale that coincides with the bull test sale. The inaugural sale was held Oct. 10, with the bred heifers shattering sale price records for 2020.
Other changes in cattle operations at Edisto include the addition of the CowManager and C-Lock programs. CowManager automatically records and reports female estrus and health data in real time to the managers and the C-Lock system weighs every bull in the bull test program, each time they drink water.
“These are cutting-edge precision ag livestock tools,” Sell said. “The future is bright for cattle and forages research at the Edisto REC.”
The Edisto Research and Education Center is one of six research and education centers in South Carolina. Research is conducted in laboratories, farms and forests at these centers, which are strategically located in the state's distinct soil and climate regions.
Denise Attaway reports for Public Service and Agriculture in the Clemson University College of Agriculture, Forestry and Life Sciences.