The judgment and prevention of the lack of nutrient elements in flowers, and what preparations should be made before flower seeds are sown?

The nitrogen deficiency plant is thin, the branches are slender and hard, and the leaves and florets are small. The leaf color from the old leaf to the new leaf gradually changes from thick green to light, and then appears reddish purple, until the wilting yellow falls off, and in serious cases, the whole plant loses green.

Prevention and treatment methods to increase the application of rotten human feces and urine, cake fertilizer, barnyard manure or ammonium sulfate, urea, ammonium nitrate and other fertilizers. The phosphorus-deficient leaves changed from dark green to copper, and the veins (especially the petiole) were yellow and purplish. It is difficult to form flower buds, and the flowers are small and light in color, resulting in poor fruit development, or even early withering and withering.

The prevention and treatment methods include bone meal, fish meal, poultry fertilizer or calcium superphosphate, ammonium phosphate and potassium phosphate (phosphorus and potassium compound fertilizer). Generally, about 0.10% aqueous solution is used as extra-root topdressing.

The potassium-deficient plants are short and the stems are soft and easy to lodge. The leaves often shrink, the old leaves appear black-brown spots along the leaf edge by the leaf tip, the leaves turn yellow around the leaves, and the pulse in the middle and leaves is still green.

The control method is to increase the application of plant ash, 1%-2% potassium chloride aqueous solution (bulbs and flowers are prohibited), 0.30%-0.50% potassium nitrate aqueous solution as extra-root topdressing, and inorganic fertilizers such as potassium phosphate.

The calcium-deficient tender leaves are green and wrinkled, the leaf edges are curled and have white stripes, the flowers are blocked, and the new leaves are difficult to unfold or distorted in a diseased manner. In the first half of the month before sowing or potting, applying an appropriate amount of calcium chloride in the soil can increase calcium and disinfect (acidic flowers are prohibited), and calcium nitrate can also be used as topdressing.

The growth of mg-deficient plants was not exuberant. From bottom to top, the old leaves gradually turn green and white from the edge of the leaves to the center, and there are various spots on the veins, and finally the whole leaves turn yellow.

The prevention and control method was sprayed with 0.20%-0.40% magnesium sulfate aqueous solution continuously for 3? 4 times, each time at intervals of 7 to 10 days. Soils with severe magnesium deficiency were mixed with 5-10 kg magnesium sulfate per mu and mixed with base fertilizer in autumn or winter.

The sulfur-deficient tender leaves yellowed from the leaf veins to the yellowing of the whole leaves, and the root system developed abnormally.

Iron deficiency ranges from tender leaves to yellowing of old leaves. The prevention and control methods of sulfur deficiency and iron deficiency can be sprayed with 0.30% ferrous sulfate solution for 3 times in a row, each time with an interval of 1 week. At the same time, 0.20% urea hot metal solution can be used for extra-root topdressing.