Medel Jimenez, Francisco

Optical crop sensors can help to mitigate environmental impacts caused by crop cultivation. These sensors allow farmers to vary the rate of nitrogen application based on crop requirements. Nevertheless, the use of these sensors may carry additional environmental burdens due to their manufacturing and use together with the direct effects on soil emissions. The aim of this study was to evaluate the environmental impacts of using a ground-based optical crop sensor for variable-rate nitrogen application by using a life cycle assessment together with the DeNitrification-DeComposition soil model in order to quantify site and technology-specific soil emissions. Results show that the global warming potential of conventional nitrogen application is 2.008 kg CO2 eq/ha compared to the 1.971 kg CO2 eq/ha produced by using the crop sensor. In the case of human toxicity potential, the conventional nitrogen application scenario is 1.566 kg 1,4-DCB/ha versus the 1.531 kg 1,4-DCB/ha of the scenario using the sensor. Soil emissions due to fertilization are responsible for most of the emissions in the majority of the environmental impacts followed by the nitrogen production process. Global warming potential related to information telecommunication technologies (ICT) components including the sensor is 0,275 kg of CO2 eq/ha; these components represent less than 3% in all impact categories. Consequently, sensor-based nitrogen application can mitigate agricultural emissions producing minimal environmental impacts the sensors’ operational and manufacturing processes.