Use of NIR hyperspectral imaging to detect and quantify nodules on root system of associated crops

Winter wheat and peas cultivated in association and harvested when grains are dry show promising results in temperate areas. This association reach a good land equivalent ratio, reduce the nitrogen fertilizer needs and obtain high quality harvest. These results are probably explained by the transfer of nitrogen from peas nodules to wheat roots. To test this hypothesis, quantification of nodules is required. Visual counting of nodules is time consuming and discrimination between the two kinds of roots is almost impossible. A new method is therefore needed. Near infrared hyperspectral imaging (NIR-HIS) was tested as a rapid method to quantify the amount of nodules and roots of each species in soil samples.