Analysis of Key Points of Pollution-Free Cultivation Techniques for Bonsai
A. Steiner, chairman of the International Pollution-Free Cultivation Association, clearly defined pollution-free cultivation as nutrient solution cultivation.
Plants center on the physiological functions of inorganic nutrient elements. Pollution-free cultivation refers to the use of inorganic nutrient solutions to directly provide plants with the nutrient elements essential for growth, replacing the cultivation method in which soil and organic matter normally provide nutrients to plants. In pollution-free cultivation, the nutrient solution can be sprayed directly onto the root system (aeroponics), or plants can be grown directly in a flowing inorganic nutrient solution (hydroponics), or sterilized microporous inorganic ores and inorganic fibers can be used as the substrate, with an inorganic nutrient solution used to directly cultivate plants (inorganic substrate culture). Therefore, so-called "vermiculite + horse manure," "sawdust + human feces and urine," and "peat + nutrient solution" should not be classified within the scope of modern pollution-free cultivation techniques.
In the United States, Japan and some Western European countries, solution culture of bonsai and greenhouse crops has gradually replaced traditional soil cultivation. Traditional soil culture must rely on the activity of bacteria in the soil to convert organic nitrogen and ammonium nitrogen into nitrate nitrogen that plants can readily use. Soil sterilization is intended to kill harmful microorganisms and insects while preserving beneficial microorganisms in the soil (such as nitrifying bacteria) as much as possible, and at the same time to eliminate weed seeds, so as to increase plant yield and quality. This makes the sterilization of soil and organic substrates (sawdust, leaf mold, peat, cottonseed hulls, etc.) relatively difficult. In contrast, nutrient solution cultivation and its continuous improvement can keep the root system in a highly aerated and sterile (or nearly sterile) environment, making plants easy to cultivate. This new technique is gradually being recognized and used by people, and its prospects for development are very broad. This is because it can not only produce plants of excellent quality and high yield, but more importantly, the products are pollution-free and can meet export quarantine requirements. This is something traditional soil culture cannot compare with. Pollution-free bonsai produced by nutrient solution cultivation can withstand strict customs quarantine in various countries, making international trade in bonsai commodities closer and more prosperous. Japanese bonsai benefited from accelerated cultivation with nutrient solutions, improving bonsai productivity and quality, and enabling it to break through the strictly guarded quarantine barriers of Europe and the United States, exporting large quantities of bonsai and thereby capturing the international market. Only through pollution-free cultivation can Chinese bonsai commodities also enable large quantities of bonsai to break out of the country and enter the fiercely competitive world market.
The key points of pollution-free cultivation for bonsai are as follows:
The concentration of the nutrient solution should follow the principle of being dilute and light, and an inorganic nutrient solution with balanced ion absorption must be used. This is the key to cultivation. (Please refer to the attached notes.)
Cultivation under rain-sheltered conditions is advocated. At this time, nutrients in the pot are not easily leached away, and there are very few diseases and insect pests.
The cultivation substrate can be made by mixing sterilized vermiculite, perlite and river sand in equal amounts. Of course, other mixtures can also be used, such as adding inorganic materials like rock wool and coal cinders. These sterilized mineral mixtures have microporosity, keeping the root system of bonsai plants in an aerated environment, which is beneficial for the re-rooting and growth of tree stumps. On top of the substrate, according to the requirements of the planted stump bonsai, small stones of harmonious color or cultivated moss can be placed. If because the pot walls are very shallow, the substrate is loose, has low specific gravity and is light in weight, making it difficult to fix the tree stump, the stone-anchoring method can be used to stabilize the roots. Use ying stones, axe-split stones, etc. placed on top of the root substrate to help reinforce and press down the roots. First, this can prevent the stump bonsai from tipping over; second, strange stones accompanying ancient trees add even more natural scenery. Even for cliff-style tree stump bonsai, although microporous ore is used as the substrate, with the assistance of ying stones and the like, the root system can still be stabilized, making the plant secure and firm.
Attached notes: Nutrient solution formula for pollution-free cultivation of bonsai
I. Macroelements (agricultural grade): calcium nitrate 0.8 g; potassium nitrate 0.4 g; monopotassium phosphate 0.25 g; magnesium sulfate 0.4 g.
II. Microelements (industrial grade or pharmaceutical grade): disodium edetate 20 mg; ferrous sulfate 15 mg; manganese sulfate 4 mg; boric acid 6 mg; zinc sulfate 0.2 mg; copper sulfate 0.1 mg; ammonium molybdate 0.2 mg.
III. Tap water: 1000 ml (1 kg). The nutrient solution is slightly acidic, and the pH value is adjusted to 6.0 with phosphoric acid. The nutrient solution is suitable for bonsai such as five-needle pine, Buddhist pine, boxwood, orange jasmine, Fukien tea, banyan, Japanese bush cherry, serissa, creeping juniper and heavenly bamboo.