What aspects should be considered when using biofertilizers on fruit trees?

　　Fruit growers may encounter certain misconceptions when fertilizing their trees. Proper fertilization can boost fruit yields, so let’s explore the key considerations for using biofertilizers on fruit trees.

　　1. Temperature Control

　　The microorganisms in biofertilizers are generally most active when soil temperatures range between 18 and 25°C; therefore, soil temperature directly influences the optimal timing for fertilizer application. For greenhouse crops, it is advisable to carefully regulate air temperature during winter, as air temperature drives fluctuations in soil temperature. During the day, maintain an air temperature of 25–30°C inside the greenhouse, and at night, cover the soil with crop residues or mulch to help retain heat.

　　2. Humidity Control

　　Experts point out that soil drought can severely hinder the growth and reproduction of microbial communities, while excessive watering reduces oxygen levels in the soil, also negatively impacting microbial activity. They recommend maintaining an optimal soil moisture level of around 60%. For fruit growers, irrigation is typically carried out on sunny mornings, but large-scale flood‑irrigation should be avoided.

　　3. Combined application of organic fertilizers

　　The level of organic matter in the soil directly determines the efficacy of bio‑fertilizers; therefore, be sure to apply an adequate amount of organic fertilizer before transplanting to ensure that the bio‑fertilizer applied later achieves its full potential.

　　4. Ingenious Fertilization

　　Bio‑fertilizers can be applied not only as a base fertilizer but also as a topdressing. For base application, hole‑application yields the best results, as it helps beneficial microorganisms rapidly establish colonies around the plant roots, thereby supporting root growth. However, this is not an absolute rule; when the soil harbors a high load of pathogenic microbes, a mixed‑application approach is recommended to increase the population of beneficial microorganisms and enhance disease‑suppression efficacy.

　　5. Choose an appropriate biofertilizer

　　The market offers a wide variety of bio‑fertilizers, and the active microbial strains they contain vary considerably. Therefore, to enhance fertilizer efficacy, it is inadvisable to apply multiple types of bio‑fertilizers or to frequently switch among them. This is because microorganisms maintain symbiotic, competitive, and antagonistic relationships, and the dominant microbial strains differ from one product to another; thus, it is best to use the same type of bio‑fertilizer consistently.

　　6. Fungicides and biological agents should not be applied simultaneously.

　　The function of a fungicide is to kill pathogenic fungi; therefore, it may also eliminate the beneficial microorganisms in microbial fertilizers, thereby compromising fertilizer efficacy. This point requires particular attention.