What should be noted when using organic fertilizer as a top dressing?
Organic fertilizer is not only an ideal base fertilizer but can also be used as a top dressing; it is the main type of fertilizer that supplies nutrients during crop growth. The following points should be noted when using organic fertilizer as a top dressing:
Apply organic fertilizer in advance
It contains quick-acting nutrients, but the quantity is limited, and the release of a large amount of slow-release nutrients requires a certain process, so organic fertilizer should be applied a few days in advance when used as a top dressing.
Apply high-quality organic fertilizer as a top dressing
During rapid crop growth, large amounts of nutrients such as nitrogen and potassium are needed. Generally, the nitrogen and potassium content in organic fertilizer is not high. To ensure the nutrient demand for rapid crop growth, choose high-quality organic fertilizer with relatively high nitrogen and potassium content.
Establish a reasonable ratio between base fertilizer and top dressing
When soil temperature is low, microbial activity is weak and organic fertilizer nutrients are released slowly, so most of the application amount can be used as base fertilizer; when soil temperature is high, microbial decomposition capacity is strong, and if too much base fertilizer is applied, the fertilizer will be excessively decomposed by microorganisms before planting, and after planting it will immediately take effect, sometimes causing excessive vegetative growth of crops. Therefore, when cultivating crops under high-temperature conditions, it is best to reduce the base fertilizer application rate and increase the top dressing application rate.
Use an appropriate amount for seedling raising
Crop seedlings have a small nutrient requirement, but insufficient nutrients cannot produce strong seedlings, which is unfavorable both for transplanting and for subsequent crop growth. Fully decomposed organic fertilizer releases nutrients evenly and has a complete nutrient profile, making it an ideal fertilizer for seedling raising. Generally, fully fermented organic fertilizer is mixed with a certain amount of peat moss, vermiculite or perlite, and mixed evenly with soil to use as a seedling substrate; the amount of organic fertilizer must not exceed 10% of the total weight of the nutrient soil.