Low-cost ground-based NDVI sensor device for manual and automated crop monitoring

Ground-based NDVI sensors are vital for an accurate, localized crop condition and growth assessment, but their high cost and labor-intensive nature limit accessibility. Here, we present a low-cost NDVI sensor device, priced under 250 Euros, which can be utilized both manually as a handheld tool and automatically as a standalone device to address this issue. We calibrated and field validated the low-cost NDVI sensor against a commercial sensor for ground-based NDVI measurements. Our calibration revealed a slight underestimation at higher NDVI values measured from the low-cost sensor, which we adjusted using a correction function. Field validation proved the accuracy of low-cost sensor device, with a high correlation (r² = 0.99; y = 1.04x + 0.003) and good agreement with the reference device, after applying then derived correction function. Further field trial application of the low-cost sensor as a handheld device (manual mode) in Benin and the Philippines for rice and pineapple cultivation, respectively, demonstrated the reliability of the device to monitor crop development and biomass accumulation. An additional field testing in an oat field site in Germany showed that the developed low-cost NDVI sensor, functioning as a standalone automatic device, is robust, reliable and capable to monitor crop development during senescence, through higher temporal resolution NDVI measurements. This study proved the accuracy and reliability of our low-cost NDVI sensor, increasing accessibility to cost-effective, ground-based NDVI crop monitoring solutions.Contains the index of all datasets. Related datasets are listed in the metadata element 'Related Identifier'. Dataset version 1.0