In the sun-drenched fields of the Mediterranean, a quiet revolution is taking place. Researchers are harnessing the power of technology to optimize forage production, and their findings could reshape the way we think about agriculture and energy. At the heart of this innovation is Luís Silva, a researcher from the Earth Sciences Department at NOVA School of Science & Technology, NOVA University Lisbon. Silva and his team have been exploring how proximal optical sensors can transform nitrogen fertilization in winter forage crops, a breakthrough that could have significant implications for the energy sector.
The study, published in the journal ‘Sensors’ (translated to English as ‘Sensors’), evaluated the performance of various sensors in recommending and monitoring variable rate nitrogen fertilization. The sensors used included a handheld multispectral active sensor (HMA), a multispectral camera on an unmanned aircraft vehicle (UAV), and a passive on-the-go sensor (OTG). These tools generated real-time nitrogen application prescriptions, offering a more precise and efficient approach to fertilization.
The results were striking. The real-time N fertilization method promoted a 15.23% reduction in the total N fertilizer applied compared to a usual farmer-fixed dose of 150 kg ha−1, saving 22.90 kg ha−1 without compromising crop productivity. “This is a significant step forward,” Silva explains. “It’s not just about reducing costs; it’s about optimizing resources and promoting sustainability.”
The sensors showed strong correlations with key agronomic parameters. For instance, the NDVI_OTG sensor demonstrated a moderate simple linear correlation with plant fresh matter (PFM) (R2 = 0.52), confirming its effectiveness in prescription based on vegetative vigor. The UAV_II sensor, which measures NDVI after fertilization, showed even stronger correlations with crude protein (CP) (R2 = 0.58), crude protein yield (CPyield) (R2 = 0.53), and N uptake (NUp) (R2 = 0.53). “These correlations highlight the sensitivity of these sensors to physiological responses induced by N fertilization,” Silva notes.
The handheld multispectral active sensor (HMA), despite operating via point readings, also proved effective, with significant correlations to NUp (R2 = 0.55) and CPyield (R2 = 0.53). This versatility is a testament to the potential of these technologies in diverse agricultural settings.
The implications for the energy sector are profound. Efficient nitrogen fertilization can lead to increased crop yields, which in turn can be used to produce bioenergy. This not only diversifies the energy mix but also promotes sustainability by reducing reliance on fossil fuels. “The integration of sensors enables both precise input prescription and efficient monitoring of plant physiological responses,” Silva says. “This fosters cost-effectiveness, sustainability, and improved agronomic efficiency.”
As we look to the future, the potential for these technologies to shape the agricultural and energy landscapes is immense. The research by Silva and his team is a beacon of innovation, guiding us towards a more sustainable and efficient future. The study, published in ‘Sensors’, is a testament to the power of technology in transforming traditional practices and paving the way for a greener tomorrow.