Evaluation of residual plastic film pollution in pre-sowing cotton field using UAV imaging and semantic segmentation

Abstract

To accurately evaluate residual plastic film pollution in pre-sowing cotton fields, a method based on modified U-Net model was proposed in this research. Images of pre-sowing cotton fields were collected using UAV imaging from different heights under different weather conditions. Residual films were manually labelled, and the degree of residual film pollution was defined based on the residual film coverage rate. The modified U-Net model for evaluating residual film pollution was built by simplifying the U-Net model framework and introducing the inception module, and the evaluation results were compared to those of the U-Net, SegNet, and FCN models. The segmentation results showed that the modified U-Net model had the best performance, with a mean intersection over union (MIOU) of 87.53%. The segmentation results on images of cloudy days were better than those on images of sunny days, with accuracy gradually decreasing with increasing image-acquiring height. The evaluation results of residual film pollution showed that the modified U-Net model outperformed the other models. The coefficient of determination(R2), root mean square error (RMSE), mean relative error (MRE) and average evaluation time per image of the modified U-Net model on the CPU were 0.9849, 0.0563, 5.33% and 4.85 s, respectively. The results indicate that UAV imaging combined with the modified U-Net model can accurately evaluate residual film pollution. This study provides technical support for the rapid and accurate evaluation of residual plastic film pollution in pre-sowing cotton fields.

A Review of Plastic Contamination Challenges and Mitigation Efforts in Cotton and Textile Milling Industries

“…with or without irrigation in different countries, and it also significantly increases the amount of cotton that can be harvested early, preventing lint quality deterioration in the field after boll opening [38][39][40]. These improvements are a result of the capabilities of plastic film mulching to regulate soil temperature, defeat weed growth, and reduce soil water loss, therefore increasing cotton water use efficiency [41]. However, despite the proven advantages of the agricultural practice of mulching with plastic films, the resulting residual plastics in the field are recognized as a common soil pollutant that has been reported to impair soil quality in different world regions, thus cancelling out the economic benefits of the practice [41][42][43][44][45][46][47][48][49][50][51][52].…”

“…These improvements are a result of the capabilities of plastic film mulching to regulate soil temperature, defeat weed growth, and reduce soil water loss, therefore increasing cotton water use efficiency [41]. However, despite the proven advantages of the agricultural practice of mulching with plastic films, the resulting residual plastics in the field are recognized as a common soil pollutant that has been reported to impair soil quality in different world regions, thus cancelling out the economic benefits of the practice [41][42][43][44][45][46][47][48][49][50][51][52]. Moreover, during cotton harvesting, the residual plastics are sometimes picked up together with the seed cotton leading to plastic contamination in cotton.…”

“…Finally, across different countries that cultivate cotton, there have been studies aimed at detecting diverse types of plastic trash in cotton fields using remote sensing and image processing techniques [41,[81][82][83][84]. These techniques, which majorly use images taken from unmanned aerial vehicles (UAVs) with a single or multiple multispectral camera(s) on board, have shown good prospects for detecting plastic in cotton fields at different stages of crop physiological maturity and have thus been proposed for in-field management/mitigation of plastic contamination of seed cotton to create maps of plastic locations within cotton fields that can aid retrieval before harvesting [83].…”

A Review of Plastic Contamination Challenges and Mitigation Efforts in Cotton and Textile Milling Industries

“…with or without irrigation in different countries, and it also significantly increases the amount of cotton that can be harvested early, which prevents lint quality deterioration in the field after boll opening [27][28][29]. These improvements are a result of the capabilities of plastic film mulching to regulate soil temperature, defeat weed growth, reduce soil water loss, and therefore, increase cotton crop water use efficiency [30]. However, despite the proven advantages of the agricultural practice of mulching with plastic films, the resulting residual plastics in the field are recognized as a common soil pollutant that has been reported to impair soil quality in different regions of the world; and thus, cancels out the economic benefits of the practice [30][31][32][33][34][35][36][37][38][39][40][41].…”

“…Across different countries where cotton is cultivated, there have been some research studies aimed at detecting different types of plastic trash in cotton fields using remote sensing and image processing techniques [30,[71][72][73][74]. These techniques which mostly rely on imageries taken aboard unmanned aerial vehicles (UAVs) with one or multiple multispectral camera(s) on board have shown good prospects for the detection of plastic in cotton fields at different stages of the crop physiological maturity and thus, have been proposed for in-field managing/mitigation of plastic contamination of seed cotton to create maps of plastic locations within cotton fields that can aid retrieval before harvesting [74].…”