Agroecology describes crops in the field as ecological systems. Like in any other ecosystem, there is a strong interaction between the plants and competition for limited resources. While other stable, ”natural” ecosystems have developed structures to minimise or avoid competition between individual plants and species, fields as monocultures with plant densities maximized for yield are always extremely competitive. This emphasises that the performance of a plant in a field does not only depend on general environmental conditions (soil, light, temperature, water etc.), but to a large degree on the way it deals with competition for light (including shade avoidance), water and nutrients (shoot and root competition). Like in any other ecological system, the number of interacting parameters is high, but appropriate test design and modelling will help to get a better understanding of these interactions and the way plants grow in highly competitive environments.
Corn and wheat fields are a good example for the sort of highly competitive ecosystems described in agroecology
Contribution of LemnaTec scanalyzer systems to agroecological research
Agroecology - Current plant phenotyping is strongly focused on the quantitative assessment of individual plants while minimising competition (“one plant per pot!”), to identify the specific influences of genes. There are, however, no technical or measurement limits in LemnaTec scanalyzer3D units when it comes to analysing competitive systems with a similar attention to detail and depth. As a common, well-grown wheat plant already has several tillers and a leaf density too high to assess each leaf individually, it is only a short step from here to planting in conditions close to field-density. Using containers that cover almost the entire footprint of the plant carrier will allow for areas between 0.036 and 0.2 m², depending on the plant carrier. Such areas enable the planting of reasonable amounts of test objects in a single container. For conveyor systems with plant carriers placed in maximum density, this leads to an almost closed container field and thus to a minimisation of border effects for each container. Therefore, light competition between containers is quite similar to competition within one container. Unintentional competition between particularly small or large plants is minimised through randomisation. For specific cultures like corn, the distance between the conveyor lines is quite similar to seeding lines in a field – depending on the type of plant carrier distances between 200 mm (one plant in a 1 mm plant carrier) and approximately 120 mm (2 plants in a 250 mm plant carrier or 3 plants in a 400 mm plant carrier) are quite similar to field densities. Such scenarios should even allow the measurement of leaf orientation close to field conditions in LemnaTec scanalyzer3D units (leaf angle measurement).