For mulberry fertilization, the amount of fertilizer and the period of application should be determined according to the characteristics of fertilizer demand. Based on the annual output of 2 tons of fresh leaves per 667 square meters, 30 to 35 kg of nitrogen, 12 to 14 kg of phosphorus, and 15 to 17 kg of potassium are required. The ratio of nitrogen, phosphorus, and potassium is 10: 4: 5 (if silkworms are produced) Species, the ratio of nitrogen, phosphorus and potassium is 5: 3: 4).

Mulberry fertilization is divided into spring fertilizer, summer fertilizer, autumn fertilizer and winter fertilizer. Determine the type and quantity of fertilization according to the change of seasons, the growth rule of mulberry trees, and the need for fertilizer.

1. Spring fertilizer: The mulberry tree germinates during the Spring Festival and consumes the nutrients stored in the tree. According to research, the spring fertilizer is only absorbed by the mulberry tree when the spring leaves open around the fifth leaf. Spring fertilizer is generally dominated by nitrogen fertilizer, such as urea, etc., and the dosage is 15-20 kg per mu. In order to reduce the loss of fertilizers, it is advisable to apply them in two times, respectively in mid-March and early April.

2. Summer Fertilizer: In June and July, the temperature is high and the rain is sufficient, which is the period of the most prosperous mulberry production, and the demand for nutrients is the largest. If you can fertilize in time and supply enough nutrients for the mulberry tree, the leaves of the mulberry tree will grow vigorously, the branches will be long, and the yield of summer and autumn leaves will be high. In order to improve the fertilizer efficiency, it is recommended to apply it twice, and apply it as soon as possible after the first spring silkworm rearing, 20 kg urea per acre (late May); the second application in the first and middle of July, 15 kg urea per acre, and Combined with the application of 20 kg of phosphate fertilizer and 5-10 kg of potassium fertilizer, weeding or surface weeding should be done to mix the fertilizer into the soil.

3. Autumn fertilizer: generally applied in the middle and late August, with an amount of 15 kg of urea per mu. Autumn fertilizer can make mulberry branches and leaves continue to grow, delay the hardening of autumn leaves, and improve the quality of autumn leaves. It can also increase the storage nutrients of mulberry trees, enhance cold resistance and the germination rate of spring in the second year, and also have an effect on increasing the yield of spring leaves. However, the application of autumn fertilizers should not be too late or too much. By the end of August at the latest, phosphorus and potassium fertilizers should be properly applied.

4. Winter fertilizer: Fertilization after mulberry leaves are called winter fertilizer. Unlike spring, summer, and autumn fertilizers, winter fertilizer has no direct effect on leaf yield, and its main purpose is to improve soil aggregate structure and improve soil fertility. Winter fertilizer is generally composed of organic matter such as compost, garbage, straw, etc., and is decomposed by the action of microorganisms in the soil, releasing three elements of nitrogen, phosphorus, and potassium and other inorganic nutrients for mulberry absorption and utilization.

Mulberry special fertilizer