Plants leave a biological and chemical legacy in the soil on which they have grown after they grow. This invisible inheritance actually inhibits or stimulates the growth of the next generation of plants. This is demonstrated by researchers from Wageningen University & Research with drones.
In the new study in Biogeosciences, Bob van der Meij and colleagues show with drones that oats grow 10 percent larger after a mixture of radish and vetch, and 16 percent smaller when grown after perennial ryegrass, compared to growth after setting fallow. The effects of the plant heritages can be seen even more strongly in the chlorophyll concentration (and thus nitrogen concentration) in the oat leaves. It increases by 72 percent in oats grown after the mixture of radish and vetch, and decreases by 30 percent in oats grown after perennial ryegrass.
Researchers and farmers are interested in methods to measure the inheritance of previous plants with high resolution in both space and time, so that resources, such as nitrogen and phosphorus, can be used more efficiently in crop cultivation. With drones and recent remote sensing technology, measurements can be made from a height of 60 meters and with high resolution (10 cm) and on a large spatial scale (an image of the experimental field can be recorded in one go).
In the study, Van der Meij and colleagues tested which crop characteristics respond strongly to the inheritance of different green manures and how well these characteristics can be determined via remote sensing. The researchers used a drone with a hyperspectral camera. This camera measures the visible and near infrared reflectance of plants in 100 narrow spectral bands of solar radiation. The measured reflection of the solar radiation is influenced by the biochemical and structural properties of the plant.
The research team found that the test crop oats reacts strongly to the inheritance of the different green manures, in particular crop height, nitrogen and chlorophyll concentration and above-ground biomass. The results obtained with the drone and camera are very much in line with the measurements made on the ground and in the lab, especially for the height of the plants and chlorophyll concentrations in the leaves.
This new remote sensing technology makes it possible for researchers and farmers to determine a number of important plant characteristics in a non-destructive way and with high spatial resolution in the field. The process can be easily repeated throughout the growing season. Therefore, this method also offers great potential for studying the effects of predecessor crops on the growth of succeeding crops, and for designing strategies that optimize resource utilization for soil fertility and disease control.
The technology can be used both in intensive precision agriculture and for agriculture in countries where production is lagging behind the possible and often necessary production to feed the growing population. To increase production there, the detection of local nutrient deficiencies in the soil and soil-borne diseases is extremely important.
© DCA Market Intelligence. This market information is subject to copyright. It is not permitted to reproduce, distribute, disseminate or make the content available to third parties for compensation, in any form, without the express written permission of DCA Market Intelligence.