Preparation methods for soilless culture substrates and nutrient solutions for flowers

Soilless cultivation is an advanced flower-growing technique that has emerged in recent years, with the following advantages: (1) Good quality. Because the hydroponic nutrient solution is formulated according to the needs of the flowers, it is beneficial to flower growth. Thus there are many flowers, large forms, strong fragrance, bright colors, a long flowering period, and the ability to bloom early. (2) It saves nutrients, water and labor. For hydroponics, it is enough to regularly supplement the flowers with the prepared nutrient solution, which is simple to operate and saves labor and time. (3) It is clean, free of weeds, and has few pests and diseases. The fertilizer used for hydroponic flowers is a nutrient solution prepared from inorganic elements, which is both clean and hygienic.

I. Substrate

The main role of the substrate chosen for soilless cultivation is to fix the flowering plants in the container and to retain nutrients and water to supply the plants' growth. Therefore, a substrate should be chosen that has a certain water retention and drainage capacity, as well as a certain strength and stability, and does not contain harmful substances. At present, the substrates commonly used for soilless cultivation in China are: (1) Sand culture. Sand grains with a diameter of less than 3 mm are used as the substrate, and the nutrient solution generally enters the sand by drip irrigation for the flowers to absorb. (2) Gravel culture. Natural gravel, pumice, volcanic rock, etc. with a diameter greater than 3 mm are used as the substrate. (3) Vermiculite. Vermiculite is a mica-type mineral with good buffering capacity, is insoluble in water, and contains magnesium and potassium that can be used by flowers. (4) Perlite. It is a siliceous substance, mainly used for seed germination, and the effect is better when it is mixed with mudstone and sand. (5) Peat. It has good air permeability and relatively high water-holding capacity. It can be used as a substrate alone or mixed with furnace slag, etc. In addition, furnace slag, brick pieces, charcoal, asbestos, sawdust, fern roots, bark and other materials can all be used as substrates, but they need to be washed and disinfected before use.

II. Nutrient solution

Soilless cultivation of flowers requires a nutrient solution, and the various elements used in its preparation and their amounts should be determined according to the varieties of flowers being cultivated, their different growth stages, and different regions. The formula for growing flowers in the north: add 0.22 g of ammonium phosphate, 1.05 g of potassium nitrate, 0.16 g each of ammonium sulfate and ammonium nitrate, and 0.01 g of ferrous sulfate to 1 liter of water. The formula for growing flowers in the south: add 0.94 g of calcium nitrate, 0.58 g of potassium nitrate, 0.36 g of potassium dihydrogen phosphate, 0.49 g of magnesium sulfate, and 0.01 g of ferrous sulfate to 1 liter of water. How to use the nutrient solution: during the growing period, water potted flowers once a week, and the amount each time can be determined according to the size of the plant. For example, for a sun-loving flower with an inner pot diameter of 20 cm, water about 100 ml each time. For shade-tolerant flowers, reduce the amount as appropriate. In winter or during the dormant period, water once every half a month or once a month. For ordinary water supplementation, still use tap water. Flower care is basically the same as with traditional methods. When preparing the nutrient solution, if tap water is used, because it contains chlorides, which are harmful to flowers, a small amount of sodium edetate should be added. If river water and lake water are used, they need to be filtered. The temperature of the nutrient solution required by various flowers should be determined according to their ecological habits. For example, the suitable temperature for tulips is 10-12°C; for carnations, mimosa, and ferns it is 12-15°C; for chrysanthemums, gladioli, irises, hyacinths, narcissus, and lilies it is 15-18°C; for Chinese roses, roses, zinnias, African daisies, and begonias it is 20-25°C; for Victoria water lilies, cacti and other tropical flowers it is 25-30°C. When preparing and storing the nutrient solution, never use metal containers; use ceramic, enamel, plastic and glass vessels. First use a small amount of warm water at 50°C to dissolve the various elements separately, then pour them one by one into water amounting to 75% of the specified volume in the order listed in the formula, stirring while pouring, and finally add water to the full amount. When using, pour it in from different parts separately.