Jasim, A., A. Zaeen, L. K. Sharma, S. K. Bali, C. Wang, A. Buzza, and A. Alyokhin. 2020. Predicting phosphorus and potato yield using active and passive sensors. Agriculture 2020, 10, 564. https://doi.org/10.3390/agriculture10110564

Applications of remote sensing are important in improving potato production through the broader adoption of precision agriculture. This technology could be useful in decreasing the potential contamination of soil and water due to the over-fertilization of agriculture crops. The objective of this study was to assess the utility of active sensors (Crop Circle, Holland Scientific, Inc., Lincoln, NE, USA and GreenSeeker, Trimble Navigation Limited, Sunnyvale, CA, USA) and passive sensors (multispectral imaging with Unmanned Arial Vehicles (UAVs)) to predict total potato yield and phosphorus (P) uptake. The experimental design was a randomized complete block with four replications and six P treatments, ranging from 0 to 280 kg P ha-1, as triple superphosphate (46% P2O5). Vegetation indices (VIs) and plant pigment levels were calculated at various time points during the potato growth cycle, correlated with total potato yields and P uptake by the stepwise fitting of multiple linear regression models. Data generated by Crop Circle and GreenSeeker had a low predictive value of potato yields, especially early in the season. Crop Circle performed better than GreenSeeker in predicting plant P uptake. In contrast, the passive sensor data provided good estimates of total yields early in the season but had a poor correlation with P uptake. The combined use of active and passive sensors presents an opportunity for better P management in potatoes.