Periods between crop rotations, during which the soil is usually exposed and vulnerable to runoff, causing the migration of nitrates into water, but also accelerating its erosion and degrading its quality. Some crops, planted at this period (and called intercrops by extension) can reduce this problem.
Specific cultivation, planted during the period between crops rotation, when bare ground is usually exposed. These selected crops are fast growing species (white mustard, radish, canola, phacelia, vetch, trefoil, etc.) allowing to fix the excess nitrogen that is still on the ground, in order to prevent it to migrate to the groundwater or to the streams, washed away by rain. These crops also have the benefit of reducing the soil erosion and enhancing biodiversity.
The vegetation that covers the ground. The vegetation cover of a soil is an agri-environmental good practice which induces benefits, such as the mitigation of nitrogen pollution, soil protection and a greater biodiversity.
Calculation allowing to highlight areas threatened by nitrogen pollution. The nitrogen balance aims to estimate the excess part on an area, evaluating the difference between the nitrogen inputs (mineral fertilization, animal waste, urban and industry inflows, atmospheric inputs) and the exports (consumption of plants, losses in gaseous form).
Chlorophyllous aquatic plant having no leaves, no roots, no vessels, no flowers, no seeds, whose main photosynthetic pigments are chlorophylls a and b. As the name suggests, they are usually green in color.
Algae phylum whose sometimes exclusive major pigment is chlorophyll β, associated with carotene and xanthophyll. Their only reproductive organs are sporocysts and gametocysts. Their plastids elaborate starch as in the Phanerogamous. It includes three classes: Chlorophyceae, Zygophyceae and Charophyceae.