Talking about the Application of Chemical Fertilizer to Orchid

The normal growth, development and flowering of orchids need not only certain light, environmental humidity, water on the basin, clean air and proper temperature, but also correct fertilization to regulate the nutrition needs in the process of growth. The required nutrient elements, in addition to nitrogen, phosphorus and potassium, trace elements (iron, boron, zinc, aluminum, manganese, copper, etc.) are also essential.

First of all, nitrogen is not only the basic substance of protein, but also the main component of chlorophyll, enzymes, ribose, vitamins and alkaloids, while phosphorus is an indispensable element in many phospholipid compounds and enzyme molecules. Potassium can improve the colloid state and photosynthesis of protoplasts, enhance plant resistance, reduce diseases and prevent lodging.

Nitrogen, phosphorus and potassium are very important to plant survival, so the first consideration in orchid fertilization is: urea is an ideal nitrogen fertilizer; potassium dihydrogen phosphate is better for phosphorus and potassium fertilizer (other phosphorus and potassium fertilizers are not excluded). Urea, also known as carbamide, nitrogen content of 44% 46%, neutral fertilizer. After application, it is converted into amine carbonate by the action of urease secreted by microorganisms before it can be absorbed by plants. The transformation rate is related to humidity and temperature. When the humidity is moderate, the higher the temperature, the faster the transformation. The biuret content in urea is less than 1% (or less) to stimulate the growth of orchids, and more than 2% is toxic. Urea as extra-root fertilization is both economical and effective, and the spraying concentration is about 0.5%. Potassium dihydrogen phosphate can prevent premature senescence of functional leaves, enhance photosynthesis and promote the formation of carbohydrates. It is ideal to use potassium dihydrogen phosphate as external fertilization, and the concentration is 0.1-0.2%.

Trace element fertilizers (including iron, boron, zinc, molybdenum, manganese, copper, etc.) are also essential nutrients for the normal growth and development of orchids: because iron (Fe) can directly or indirectly participate in the formation of chloroplast proteins, many respiratory enzymes in plants contain iron, iron can promote plant respiration and accelerate physiological oxidation. Ferrous sulfate and organic fertilizer (such as green fertilizer, fermented pig urine) are commonly used. Temporary mixed use, can not be mixed with organic fertilizer for a long time, because the oxides produced in the soaking process will be toxic to orchid, ferrous sulfate can also be sprayed outside the root, the concentration is 0.2%. Boron (B) plays a certain role in the growth of root, stem and other organs, the development and flowering of young meristem. Boron can also accelerate the transport of carbohydrates, promote photosynthesis, nitrogen metabolism in the body, and enhance disease resistance and drought resistance. Boron fertilizer is best to use boric acid, containing 17% boron, the white crystal is soluble in water, the aqueous solution is weakly acidic, and the concentration of spraying outside the root is 0.1%; Zn is a component of enzymes in plants, which can promote photosynthesis, respiration and carbohydrate synthesis, and the formation of chlorophyll and auxin in plants is related to zinc. Zinc can enhance drought resistance, cold resistance, salt resistance and disease resistance. The commonly used zinc fertilizer is zinc sulfate (ZnSO4-7H2O), which contains 23% zinc, and ZnSO4 ·H2O contains 3540% zinc, the authentic product is white crystal, and the concentration of external fertilization is 0.05% zinc sulfate solution; molybdenum (MO) can absorb and utilize nitrogen, especially nitrate nitrogen (reduced to ammonium nitrogen can be combined with organic acid to form amino acid, and then synthesize protein). Molybdenum can improve the activity of phosphoric acid and promote the synthesis and transport of plant sugar and starch. It can reduce plant chlorosis caused by excessive manganese, zinc, copper or iron deficiency in soil, which is beneficial to photosynthesis. The commonly used molybdenum fertilizer is ammonium molybdate, which contains 54% molybdenum, and ammonium molybdate solution with a concentration of 0.02 to 0.05% is sprayed outside the root. Attention should be paid to residual poison and controlling dosage when applying molybdenum fertilizer. Manganese (Mn) plays a multifaceted role in plants. It is related to the activities of many enzymes. It is the activator of enzymes and participates in photosynthesis, nitrogen transformation, carbohydrate transfer and some redox processes. The commonly used manganese fertilizer is manganese sulfate, which contains 24% manganese. Manganese sulfate can have several different kinds of crystal water, for example, 3, 4, 5, 6, 7. A piece of crystalline water. The concentration of external fertilization is 0.05% manganese sulfate solution; copper (Cu) is the core element of various oxidase activation groups in plants and plays an important role in catalytic redox reaction. Copper can promote the formation of chlorophyll, copper-containing enzymes are related to the synthesis of protein, commonly used copper fertilizer is copper sulfate, which contains 2425% copper, is soluble, and 0.02% copper sulfate solution is sprayed outside the root.

Fertilization time: nitrogen, phosphorus and potassium fertilizer from May to June, late August to early October, once every two to three weeks, iron and boron fertilizer two times in May to June, once in September, molybdenum, manganese and copper fertilizer twice in May to June, zinc fertilizer once in the middle and last ten days of May. Mosaic varieties (editor's note: line magnolia) should apply little or no nitrogen fertilizer. Fertilization was carried out when the sun and temperature were suitable, but not in cloudy and rainy days, and it was not suitable for fertilization when the temperature was lower than 12 ℃ and higher than 30 ℃.

Feng Guoqing