Vessel experiment
The vessel experiment is used in crop production and soil science for research purposes.
Reasons for using it instead of a field trial
- In contrast to the field experiment , in the vessel experiment, corresponding research can be carried out regardless of the weather, if a climatic chamber is used.
- One container corresponds to a plot of land in a field test , which usually takes up 10 to 50 m² of space.
- Differences in soil, which are particularly important in larger experiments, can be excluded.
- Any soils or soil mixtures can be used, which is only possible in the field trial by selecting different locations that are sometimes far apart. In this way, even different soils can be used within one test under otherwise identical conditions.
Areas of application
- Plant protection
- fertilization
- Heavy metal uptake by the plant
- Phytopathology
- Nutrient shift in the soil
- Leaching of nutrients from the soil
- Display of nutrient deficiency symptoms of the plant
Trial evaluation
Parameters that can be evaluated
- Soil pH
- Nutrient content of the soil
- Degree of root penetration of the soil
- Chemical composition, especially the nutritional content of the eluate
- Crop mass of the plant
- Chemical composition of the plant
- Ratings of the plants, e.g. B. Degree of ripeness, symptoms of disease, tillage factor in cereals
statistical evaluation
The number of test vessels usually results from the product of the individual test factors plus the zero variant multiplied by the number of repetitions. A higher number of repetitions results in a higher statistical reliability of the test result. In a 2-factor fertilization attempt with z. B. 10 different fertilizers (1st factor), 2 fertilization levels (2nd factor), 4 repetitions and the zero variant, the number of containers is calculated as follows:
- Number of variants = 10 * 2 + 1 = 21
- Number of vessels = 21 * 4 = 84
Statistical dispersion
If the results of the repetitions within the variants deviate more from one another than the differences between the individual variants, this results in poorer statistical validation of the test result. This is quantified by statistical measures such as standard deviation and limit difference.
The causes of such variations in the vessel experiment can be:
- Large plants such as maize mean a small number of plants per vessel, which means that each individual plant has a greater influence on the respective vessel.
- Irregularities in watering the vessels
- Temperature differences within the test facility
- Different shading of the vessels by neighboring vessels
Vessels
- Mitscherlich vessel
- Kick Brauckmann vessel