Improving SOC estimation in low-relief farmlands using time-series crop spectral variables and harmonic component variables based on minimum sample size
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引用次数: 0
Abstract
Efficiently monitoring Soil Organic Carbon (SOC) in farmlands is crucial for environmental and agricultural sustainability. Currently, crop spectral variables are primarily employed to estimate SOC in low-relief farmlands. To enhance SOC estimation, further crop information needs to be excavated. Additionally, few studies have considered the sample size in modeling SOC estimation, which may lead to precision loss and cost waste. Therefore, this study proposed a novel method to improve SOC estimation in low-relief farmlands. This method considers more information on crop growth and minimum sample size. The results showed that: (1) time-series NDVI was established as the characteristic crop spectral variables, based on crop spectral variables extracted from eight-day time-series reflectance products. (2) Seventeen harmonic component variables were derived from time-series NDVI via Fourier transformation. (3) Six crop spectral variables and seven harmonic component variables were determined as the optimal SOC estimators. (4) The convolutional neural network model provided higher SOC estimation accuracy (R2 = 0.81, NRMSE = 7.09%) than the random forest model and the back propagation neural network model. And the minimum sample size based on the optimal model was determined to be 250. (5) The proposed method improved SOC estimation at the regional scale, achieving a 2.54% reduction in NRMSE compared to the NDVI-based model. These findings suggest that the proposed method holds the potential for efficient SOC estimation in low-relief farmlands.
期刊介绍:
The International Soil and Water Conservation Research (ISWCR), the official journal of World Association of Soil and Water Conservation (WASWAC) http://www.waswac.org, is a multidisciplinary journal of soil and water conservation research, practice, policy, and perspectives. It aims to disseminate new knowledge and promote the practice of soil and water conservation.
The scope of International Soil and Water Conservation Research includes research, strategies, and technologies for prediction, prevention, and protection of soil and water resources. It deals with identification, characterization, and modeling; dynamic monitoring and evaluation; assessment and management of conservation practice and creation and implementation of quality standards.
Examples of appropriate topical areas include (but are not limited to):
• Conservation models, tools, and technologies
• Conservation agricultural
• Soil health resources, indicators, assessment, and management
• Land degradation
• Sustainable development
• Soil erosion and its control
• Soil erosion processes
• Water resources assessment and management
• Watershed management
• Soil erosion models
• Literature review on topics related soil and water conservation research