Our innovation is a major transformation in farmers’ decision making regarding theapplication of limited resources such as water, seeds, fertilizer and labor.For this we use low-cost high-resolution Flying Sensors (UAVs) in a development context and simultaneously develop a network of service providers in Mozambique and South Africa.Instead of relying on common-sense management, farmers are now...SEE ALL
Our innovation is a major transformation in farmers’ decision making regarding theapplication of limited resources such as water, seeds, fertilizer and labor.For this we use low-cost high-resolution Flying Sensors (UAVs) in a development context and simultaneously develop a network of service providers in Mozambique and South Africa.Instead of relying on common-sense management, farmers are now able to take decisions based on facts, resulting in an increase in water productivity.SEE LESS
How does your innovation work?
A Flying Sensor is a combination of a flying platform and camera. Reliable Flying Sensors are on the market in a wide-range of categories each with its specific characteristics. Based on the consortium’s experiences over the last years low-cost Flying Sensors have been identified that are excellent equipped for our innovation. Typically a Flying Sensor flies at a height of 100 meter and overlapping images are taken about every 5 seconds. This results in individual images covering about 50 x 50 meter and an overlap of 5 images for each point on earth. So in order to cover 100 ha 500 images are taken during a flight.
We trained several Flying Sensor operators, who are going to the fields on a daily basis to gather information with their Flying Sensors and advice farmers on potential interventions they could take. These operators are able to support over 400 small-scale farmers, by collecting information and sharing it with farmers on weekly basis. Based on the information, farmers take decisions on where to do what in terms of irrigation, fertilizer application and pesticides.
When light falls on a leaf, reflection occurs. The amount of reflection of green light (0.54 µm) is very high, making plants green to the human eye. Healthy vegetation does not reflect much red light (0.7 µm), since it is absorbed by chlorophyll abundant in leafs. In the near-infrared spectrum (0,8 µm) the amount of reflection increases rapidly to 80% of the incoming light. This increase is caused by the transition of air between cell kernels. This is characteristic for healthy vegetation.
Damaged plant material does not show this increase in reflected near-infrared light. Moreover, the reflection of red light is much higher than in healthy plant material. By measuring the reflection in these spectra, damaged plant material can be distinguished from healthy plant material (Schans et al., 2011).
Our Flying Sensors have cameras which can measure the reflection of near-infrared light, as well as visible blue light. These two parameters are combined with a formula, giving the Normalized Difference Vegetation Index (NDVI). This information is delivered at a resolution of 2x2 cm in the infra-red spectrum. Infra-red is not visible to the human eye, but provides information on the status of the crop about two weeks earlier than what can be seen by the red-green-blue spectrum that is visible to the human eye.
NDVI is the most important ratio vegetation index and says something about the photosynthesis activity of the vegetation. Moreover, NDVI is an indicator for the amount of leaf mass, and therefore, ultimately biomass. In general, open fields have a NDVI value of around 0.2 and healthy vegetation of around 0.8. NDVI values give an indication of crop stress. This can be caused by a lack of water, lack of fertilizer, pests or abundancy of weeds.