When nitrogen deficiency is the primary cause of smaller and yellower plant canopies, optical sensors and cameras can help growers make decisions about late-season fertilizer applications. However, water deficiency can also affect plant canopies and thus influence the measurements by those sensors and cameras.
We found a new analysis technique of isolating nitrogen effects from water effects was developed and was found to perform better for this dataset than did two existing methods.
Publication: Lo, T.H., D.R. Rudnick, B.T. Krienke, D.M. Heeren, D.M., Y. Ge, and T.M. Shaver (2019). Water effects on optical canopy sensing for late-season site-specific nitrogen management of maize. Computers and Electronics in Agriulture 162: 154-164.