Sand culture
The sand culture is an experimental method for determining the optimal nutrients for plants, and other factors of plant growth under laboratory conditions. The principles are analogous to hydroponics , but sand culture enables ventilation of the root area. The method of sand culture was developed by Hermann Hellriegel .
Carrying out the experiment: A nutrient-free , chemically inert and sterile soil, mostly high-purity fine-grain quartz sand from Hohenbocka or Dörentrup , is poured into a glass vessel . If necessary, unsuitable sand can be prepared by washing out the fine particles with water, treating with hydrochloric acid to remove lime and then annealing. This soil forms an indifferent root bed into which the plant seeds are spread. The soil is then saturated with a nutrient solution, which consists of distilled water and the chemical elements of the nutrient requirement to be examined in ion form, for example potassium , nitrogen , phosphorus , iron and others. Particular attention must be paid to the purity of the substances used if one wants to investigate the effects of trace elements . Well-known nutrient solutions have proper names, for example from Knop and vd Crone. The concentration of the nutrient solutions is around 1–2 ‰.
Meaning: Since the usual nutrient solutions and the root bed do not contain any carbon, it is possible to prove that it is absorbed through the air. When testing nutrients, the type of fertilizer and / or its concentration is varied. Since the remaining factors such as light, humidity and heat remain constant, the influence of the nutrient solution can be read directly from the plant growth. With the method, each growth factor can also be examined individually or in combination. As a result, you can, for example, determine the optimal fertilizer for the respective plant or identify deficiency symptoms.
Limitations: The experiment does not reflect the real growth conditions of a plant, since the relationships between a plant and its environment, especially the interaction with the organisms in the soil , are very diverse.
The sand cover process , a method of amelioration of moors, must be distinguished from sand culture .
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- Brockhaus ABC der Landwirtschaft in 2 vol ., Brockhaus Verlag, 1958
- Miehe: Taschenbuch der Botanik , Thieme Verlag, 1956
- Wölfer: Principles of Agriculture , Parey, 1921