UNION CITY, TENNESSEE
Plastic contamination in cotton production is a growing concern with significant financial, environmental and reputational consequences for cotton growers. Even something as seemingly minor as a stray plastic bag caught in a cotton field during harvest can lead to extensive problems downstream.
Once harvested, cotton enters the ginning process, and plastic debris can break apart and spread, contaminating larger quantities of cotton beyond the initial point of contact. This contamination is especially problematic because plastic is difficult to detect and may not be distributed uniformly throughout the bale.
The economic impact of plastic contamination on cotton producers can be devastating. The U.S. Department of Agriculture imposes a 40-cent-per-pound discount on any bale of cotton found to contain plastic, potentially costing growers around $200 per bale. In a tight market, this loss can represent over half the value of the affected cotton.
Moreover, manufacturers face additional losses if plastic contamination slips through the grading process and enters the supply chain. Contaminated cotton can cause machinery downtime and spread further plastic debris, increasing costs at every stage.
The environmental consequences are equally severe. Plastic does not biodegrade, leaving behind long-term pollution that can infiltrate the soil. Microplastics can disrupt soil health, harming organisms critical for nutrient cycling and soil productivity. Wildlife is also at risk, as animals may ingest plastic waste, leading to injury or death.
Projects Underway
According to Dr. Ed Barnes, director of agricultural and environmental science at Cotton Incorporated, a wide variety of efforts are underway to address plastic contamination in cotton. Plans include increasing awareness among growers, improving field management practices and enhancing detection methods at gins.
“Emerging technologies like machine learning-based vision systems are being explored as potential solutions to catch contamination early and minimize its spread. Education and collaboration across the supply chain are critical in maintaining cotton’s reputation as a high-quality, environmentally sustainable product,” Barnes said.
Cotton Incorporated, USDA-ARS and researchers at Mississippi State University are working on two different projects addressing contamination in the Mid-South. One project, led by Sean Donahoe at the Stoneville Gin Lab, is compiling a data set of over 12,000 images containing over 15,000 contaminants. This data set will be crucial for modeling and training an unmanned ground vehicle in contamination detection.
Dr. Hussein Gharakhani from MSU has a project underway that uses an unmanned ground vehicle (UGV), or robot, that can detect and remove contamination in the field. Since many growers do not have the time to look for and remove pieces of contaminant from the field, the MSU “robot” would be used to identify the trash using the image databank from the previous project and automatically remove it.
“The success of a robotic system relies on a high-quality dataset for training an object detection model. This task ensures the acquisition of diverse and representative images, essential for robust model training,” Gharakhani said.
This multi-phase project, funded in part by Cotton Incorporated, started earlier this year and has three primary objectives:
1. Data Collection involves gathering data on the types and percentages of plastic contamination across various cotton fields to inform removal strategies. This involves manually collecting images and statistical data and identifying areas with the highest contamination.
2. Object Detection System: Creating a robust object detection network using collected images to train a deep learning model will help the robot accurately identify plastic waste in diverse field conditions.
3. Robotic Arm Design: Designing and fabricating a robotic arm and end-effector capable of effectively removing various types of plastic contamination without damaging cotton plants.
While the project is just getting started, Cotton Incorporated sees great value in funding the development of this UGV. “The long-term idea for these projects is not a robot solely dedicated to trash removal, but it would be just one of the many functions of a ground-based unit. Early in the season, the UGV could potentially help with pest detection and weed removal, for example,” Barnes said.
Cotton Incorporated plays a pivotal role in tackling the pressing issue of plastic contamination in cotton production. Through ongoing research and collaboration on key plastic contamination projects like the ones with MSU and USDA-ARS, Cotton Incorporated is helping to protect the economic viability and environmental sustainability of the U.S. cotton industry.