Soil spectral libraries and their role in soil analysis

Soil Spectral Libraries (SSLs) play a crucial role for advancing soil testing by integrating soil spectroscopic tools. This article aimed to examines the development, utilizations and implications of the SSLs in soil science studies. The SSLs offer rapid and cost-effective quantitative estimation of different soil properties such as soil pH, salinity, nutrients, texture, organic carbon and others which is essential for environmental monitoring and precision agriculture. Furthermore, this article highlights the potentialities of the visible/near-infrared (Vis-NIR) soil spectroscopy for creating robust prediction models and demonstrating the necessity for large, variable reference datasets of the soil samples and their corresponding spectral reflectance data to enhance the applied prediction models’ accuracy. Additionally, Open Soil Spectral Library (OSSL) aims to provide an access to the soil data and engaging the external communities in the soil data collection. There are many advantages of using the SSLs, but there are some challenges especially in predicting certain soil properties accurately; and the factors related to the used prediction models and soil types. There is a necessity for creating the SSLs in India due to its importance in achieving better soil monitoring, planning and management. The prospects for SSLs are promising whereas the applicability of the machine learning models for better estimation of soil properties can be enhanced globally through collaborative efforts and increased accessibility for stakeholders in developing regions. A key limitation of this study is that the accuracy of SSLs in predicting certain soil properties can be affected by the variability in soil types and the choice of prediction models, which may limit the generalizability of the results across diverse Indian soils. Thus, this review article comprehensive overview underscores the transformative potential of SSLs in soil analysis and their critical role in sustainable land management practices.