How to apply base fertilizer when repotting flowers? These precautions you need to know

Simple repotting and transplanting techniques can greatly increase the survival rate of plants. Let's learn about it together when repotting.

What is base fertilizer.

Base fertilizer is the fertilizer applied at the bottom of the pot when repotting or changing the soil of container plants. It mainly supplies the nutrients needed by the plant throughout its entire growth period, creates good soil conditions for crop growth and development, and also has the effect of improving the soil and building up soil fertility.

How to apply base fertilizer.

Applying base fertilizer generally needs to be considered from four aspects: the type of base fertilizer, the amount, the fertilizer variety and the depth of application. From the perspective of type, organic fertilizers (including farmyard manure, stable manure, green manure and cake fertilizer) are suitable for use as base fertilizer. In addition, nitrogen, phosphorus, potassium and micronutrient fertilizers are all suitable as base fertilizer, which is a basic step in fertilization and is crucial to crop growth and development, especially at the seedling stage and the early stage of crop growth. To determine the amount of base fertilizer to apply, especially the amount of chemical fertilizer, the level of soil fertility must be considered. In soil with organic matter below 1.2%, more than 3 cubic meters per mu of organic fertilizer should be applied. When nitrogen, phosphorus, potassium and trace elements in the soil fall below the effective critical value for crop fertilization, these fertilizers should first be chosen for base application, especially since crops need more phosphorus fertilizer in the early stage. The specific amount of various fertilizers used as base fertilizer can be determined by referring to local long-term field fertilizer efficiency test results and target yield and other comprehensive factors. Generally, on high-fertility soil about 30% of the nitrogen fertilizer amount is applied as base fertilizer, while on medium- and low-fertility soil 50%-70% of the nitrogen fertilizer is used as base fertilizer, and phosphorus, potassium and micronutrient fertilizers should all be applied as base fertilizer at once as far as possible. From the perspective of fertilizer variety, ammonium bicarbonate among nitrogen fertilizers; ordinary superphosphate, diammonium phosphate, calcium magnesium phosphate and triple superphosphate among phosphorus fertilizers; potassium chloride, potassium sulfate and plant ash among potassium fertilizers; and zinc fertilizer and manganese fertilizer among micronutrient fertilizers are all suitable as base fertilizer.

In terms of depth, base fertilizer should generally be applied within the entire plow layer, that is, at a depth of 15-20 cm. For organic fertilizer, nitrogen fertilizer, potassium fertilizer and micronutrient fertilizers, they can be mixed and evenly spread on the soil surface, then immediately plowed into the soil, so that the fertilizer is evenly mixed with the soil of the entire plow layer, which helps the absorption and utilization of nutrients by different root layers of the crop. Because phosphorus fertilizer has poor mobility and is easily fixed after being applied to the soil and thus loses its effectiveness, it should be applied in two layers when used as base fertilizer, that is, the lower layer applied to a depth of 15-20 cm and the upper layer applied to a depth of about 5 cm. The upper layer mainly meets the crop's phosphorus demand at the seedling stage, while the lower layer supplies phosphorus nutrition for the middle and late stages of crop growth.

What are the precautions for applying base fertilizer when repotting flowers.

First, when applying base fertilizer to the plant, avoid the fertilizer directly touching the plant roots, so as to prevent burning and cause unnecessary damage;

Second, do not apply too large an amount when fertilizing. Generally, for woody flowers with a pot diameter of 40 cm, the application amount is: 200-300 grams of decomposed organic fertilizer or about 20 grams of chemical fertilizer;

Third, the fertilization methods include hole application and bottom application. Hole application is to dig a hole in the pot, put the fertilizer into the hole and then cover it with soil, generally at a depth of more than 5 cm. Bottom application is generally carried out together with repotting and changing soil. After taking the plant out of the pot, first put a layer of soil at the bottom of the pot, then place the fertilizer on top of the bottom soil, then put a thin layer of soil and plant the plant. When planting, be sure to firm or tamp the soil, water thoroughly and then carry out normal care. If the plant has had a lot of soil removed, place it in a shady place for care; if no soil has been removed from the plant, it can be cared for according to the plant's habits.