Applications of remote sensing for crop residue cover mapping

Crop residue is critical for the health of soils and crops as it can maintain soil moisture, reduce soil erosion, support soil nutrient cycling, and increase soil carbon sequestration. Monitoring crop residue cover (CRC) is thus essential for understanding the distribution and amount of crop residues in the field and for developing corresponding management strategies. Remote sensing is a powerful geospatial technique that enables the collection of images covering large areas repeatedly, which can contribute greatly to CRC mapping. This paper reviews the use of remote sensing in estimating CRC, focusing on different remote sensing platforms (e.g., satellites and drones), sensors (e.g., multispectral, hyperspectral, non-optical) and analytical methods (e.g., spectral unmixing, image classification). A total of 101 studies were selected based on their relevance to the scope of this review. The review found that while remote sensing technologies have shown great potential in accurately monitoring CRC, challenges remain in data integration, sensor selection, and computational demands, pointing to the need for ongoing research to optimize crop residue monitoring. This review is expected to bring more insights to agricultural researchers and practitioners and promote developing effective techniques for CRC mapping and management.