First, look at fertilizer types Nursery fertilizers generally use quick-acting fertilizers, such as grass ash, ammonium sulfate, urea, ammonium chloride, potassium chloride, etc. These fertilizers must be completely crushed and should not be applied in blocks. Can also be followed by organic fertilizers, such as human and animal manure, compost, etc., but must be fully fermented, decomposed, should not use raw manure, and the concentration should be diluted. Nitrogen fertilizer has a strong mobility in soil and can be applied to the root distribution layer shallowly and absorbed by seedlings. Potassium fertilizer has poor mobility and poor mobility of phosphorus fertilizer, and it should be applied deep to the densely distributed root system.
Second, see the weather and fertilization According to the weather conditions determine the number of fertilization and fertilizer. The temperature is low, the seedlings absorb less, the temperature is high, the root grows vigorously, and the amount of fertilizer is absorbed. It is best to choose sunny weather and fertilize soil when it is dry. In rainy days, roots absorb moisture slowly, not only nutrients are not easily absorbed, and fertilizers are easily lost by rain, causing waste. It is best to use wet application in drought, that is, to apply fertilizer to liquid fertilizer in the water and evenly apply it to the nursery ground; moderate dry rainfall can be applied, ie, the fertilizer should be applied in a furrow, and the depth of furrow application should be in the distribution layer of the root system to facilitate seedlings. Absorption of fertilizers.
Third, look at the fertilization pay attention to different types of soil nutrients contained in different types and quantities of different types of fertilizer application. For example, in the soils of calcareous soil or strong acid nursery, phosphorus deficiency occurs, so pay attention to increasing phosphate fertilizers, especially increasing the amount of phosphate fertilizers. In general, the soil is dominated by nitrogen fertilizers. If nitrogen is sufficient, the proportion of phosphorus and potassium fertilizers should be increased. Different soil texture, nutritional conditions and fertility protection are also different, so the fertilization method is also different. Soil fertility is good, and more fertilizer can be used each time, the number of times can be less; Soil conservation poor fertility in sandy soil nursery, fertilizer frequency should be more and each dose should be less.
Fourth, see seedlings Application seedling growth is generally divided into the four stages of seedling, seedling, fast-growing and hardening. Seedling seedlings can not make nutrients on their own, and their nutrition mainly depends on the nutrients stored in the seed; seedling period refers to the emergence of true leaves on the aboveground part of the seedlings, the emergence of lateral roots underground, until the growth of seedlings has increased substantially, then sensitive to nitrogen and phosphorus Fast-growing period is the simultaneous growth of the seedlings above the ground and underground, the demand for nutrients is large, should increase the amount of nitrogen fertilizer and frequency, and proportional application of phosphorus and potassium fertilizers. In the later stage of growth, in order to promote the hardening of seedlings and increase resistance, nitrogen fertilizer should be stopped at a proper time, and it should be prevented from becoming long in the hardening period, and fertilizer application should be stopped to increase seedling resistance. Generally, annual seedlings need more N and P fertilizers in the initial stage of growth to promote the growth of young roots. In the fast growing stage, a large amount of N, P, K, and other elements are needed. In the later growth stage, potassium is the main component, and phosphorus is used as the supplement to promote young stem woodiness. Change. For seedlings of large-scale seedlings, the root system is strong, distributed far, and fertilization should be deep, and the scope should be large, such as Pinus tabulaeformis, Ginkgo biloba, Acacia, skunk, and so on. The roots with large seedlings should be shallow and fertilized, and the range should be small. Tong, Amorpha fruticosa and flower shrubs.
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