Influence of nitrogen fertilisation on maize growth and yield detected by active optical sensor

Abstract

The influence of fertilization with different dosages on field crops yield has been confirmed in a number of research. The correlation between applied doses of nitrogen fertilizer and plant growth and yield in maize (Zea mays L.) is high. The results of the spectral analysis of plants are commonly expressed in a more intuitive manner as vegetation indices which represent mathematical combinations of surface reflectance at two or more wavelengths and they have been adopted with the aim to highlight particular properties of a plant. In this paper, we used, portable active multispectral optical device for precise plant stress detection and field mapping named Plant-O-Meter. The device has an integrated multispectral source that comprises light sources of the four most indicative wavelengths (850, 630, 535 and 465 nm), and enables simultaneous illumination of the whole plant. Sequential illumination and detection provide rapid reflectance measurements, which are wirelessly transmitted to android operated devices for processing and data storing. In this experiment, we have detected different vegetation indices during the vegetation season of maize, treated with 16 different combinations of basic and additional fertilizations with nitrogen fertilizers. There was a correlation between some of the vegetation indices and maize yield parameters. Based on this research and additional experiments from other localities, it is possible to design an algorithm for early prediction of maize yield based on types and dosage of applied nitrogen fertilizers.