Characteristics of Mulberry Fertilizer Requirement and Fertilization Technique and Time for Superior Yield in China

The characteristics of fertilizer demand and high yield fertilization technology and time of mulberry in China: Mulberry is a perennial deciduous woody plant, which collects leaves many times every year to raise silkworms and takes away a lot of nutrients from the soil. Therefore, mulberry needs more nutrients, about 1.5 kg of nitrogen, 0.8 kg of phosphorus and 1.0 kg of potassium for every 100 kg of fresh mulberry leaves. Among them, the demand of nitrogen and potassium is the highest. The nutrient absorption of mulberry varies in different periods. Mulberry branches and leaves in spring. Before the fifth leaf exhibition, the required nutrients mainly rely on the stored nutrients in the tree. After the sixth and seventh leaves unfold, the branches and leaves grow rapidly and the nutrient absorption is accelerated. In the spring silkworm period (in May to the south of the Yangtze River), mulberry growth entered a prosperous period, and the first peak of nutrient uptake appeared. After summer felling, the root system stopped absorbing nutrients, and with the re-germination, the branches and leaves of mulberry grew rapidly and gradually entered the second prosperous period (in June, July and August to the south of the Yangtze River), and the nutrient uptake reached the second peak. In autumn and winter, mulberry trees grow slowly and absorb less nutrients until they are dormant.

When applying fertilizer to mulberry trees, the amount of fertilizer and the period of application should be determined according to the characteristics of fertilizer demand. According to the annual output of 2 tons of fresh leaves per 667m2, it is necessary to apply nitrogen 3035kg, phosphorus 12 ~ 14kg, potassium 1517kg, and the ratio of nitrogen, phosphorus and potassium is 10:4:5 (if silkworm eggs are produced, the ratio of nitrogen, phosphorus and potassium is 5:3:4).

Mulberry fertilizer is divided into spring fertilizer, summer fertilizer, autumn fertilizer and winter fertilizer. The type and quantity of fertilizer are determined according to the change of season, the growth law of mulberry and the need for fertilizer.

1. Spring fertilizer: Mulberry Spring Festival germination consumes the stored nutrients in the tree. According to research, when the spring leaf blooms to about the fifth leaf, spring fertilizer is absorbed and utilized by mulberry. Spring fertilizer is generally dominated by nitrogen fertilizer, such as urea, with a dosage of 15-20 kg per mu. In order to reduce fertilizer loss, it should be applied twice, in mid-March and early April, respectively.

two。 Summer fertilizer: in June and July, the temperature is high and Rain Water is full, which is the most exuberant period of mulberry production and the greatest demand for nutrients. If the mulberry can be fertilized in time and provide enough nutrients, the mulberry branches and leaves will grow vigorously, the branches will be long, and the yield of summer and autumn leaves will be high. In order to improve fertilizer efficiency and advocate secondary application, 20 kg of urea per mu was applied as early as possible after the end of the first spring sericulture (late May); the second was applied in the first and middle of July, 15 kg of urea per mu, combined with 20 kg of phosphate fertilizer and 5-10 kg of potash fertilizer, ditch application or surface application of weeding to achieve mixed fertilizer into the soil.

3. Autumn fertilizer: generally applied in the middle and late August, the amount of urea per mu is 15 kg. Autumn fertilizer can make the branches and leaves of mulberry grow continuously, delay the hardening of autumn leaves, improve the quality of autumn leaves, increase the storage nutrients of mulberry, enhance the cold resistance and the germination rate of the following spring, and also play a role in increasing the yield of spring leaves. However, the application of autumn fertilizer should not be too late or too much, by the end of August at the latest, and appropriate application of phosphorus and potash fertilizer.

4. Winter fertilizer: mulberry fertilization after defoliation is called winter fertilizer. Different from spring, summer and autumn fertilizer, winter fertilizer has no direct effect on leaf yield, its main purpose is to improve soil aggregate structure and improve soil fertility. Winter fertilizer generally uses organic matter such as compost, garbage and rice straw to decompose depending on the role of microorganisms in the soil, releasing nitrogen, phosphorus, potassium and other inorganic nutrients for mulberry absorption and utilization, its fertilizer effect is slow and long-lasting, and the nutrients are comprehensive.