- Nov 24, 2017 -
Why do we use foliar fertilizer? Not only because crops can absorb and obtain nutrients effectively through the leaves directly, but also because some nutrients are often easily fixed by the soil, the utilization by root system is decrease a lot.
The nutrient absorption and transformation rate by leaf are much faster than by root. Take example of Urea, we can see the effect in the very same day by foliar spray, while it needs 4-5days by fertigation in the root.
Foliar spray can promote absorption of nutrients and improve fertilization effect by root system. With certain nutrients by foliar spray, it can adjust the enzyme activity, promote the formation of chlorophyll, increase the photosynthesis, and improve the quality and increase yield. In short, foliar spray is a low-cost, efficient, simple, and easy way to promote. However, the absorption of nutrition by crops mainly depends on the root system, and the root fertigation is still the mainstay of production, while foliar fertilizer only as an auxiliary way. To get the ideal effect, both foliar spray and root fertigation should be combine together.
Foliar spay needs to dilute the fertilizer in water in a certain times, and spray onto leaves, especially suitable for trace elements fertilizers. Here are some tips:
1. Use the proper fertilizers. There’s a lot suitable fertilizer, such as Urea Phosphite, Potassium Phosphite, superphosphate, Potassium Polyphosphate, Zinc Phosphite , Wood Vnegar, liquid Boron, rare earth and ash leachate, etc., but the volatile, insoluble fertilizer is not suitable , such as ammonium bicarbonate, calcium magnesium phosphate and so on.
2. Diluted the fertilizer in a certain times water, rather thinner not thick. Appropriate concentrations of foliar application of fertilizer:Urea Phosphite600-1000 time, Potassium Phosphite 600-1000time, ammonium sulfate 0.2% -0.3%; liquid Boron 700-13000times, superphosphate 1% -2%; rare earth 0.3% -0.1% and so on.
3. Application properly. The plant leaves evenly covered with small droplets of diluted fertilizer, without trickle.
4. Spraying position. Application onto the young vegetable stems and leaves on front and back side both, do not skip or spray twice.
5. The application timing. Leafy vegetables are usually applied in the early and mid-growth stages; and solanaceous, melon, legumes, and rhizomes are usually applied in the mid and late-stage.
Foliar spay should applied in a sunny afternoon when the sun getting weaker, to extend the fertilizer stay on the leaves to improve efficiency. If it rains in 3 hours after the application, re-spay when the weather turns fine, but the concentration of fertilizer should be appropriate decline.
6. The times of foliar spraying should be appropriate. Usually 2-3 times, once every 7-10 days.
7. Choose the proper fertilizer. Leafy vegetables, such as cabbage, celery, spinach and other foliar suggested to use Urea Phosphite, Potassium Phosphite; solanaceous fruits and vegetables such as tomatoes, cucumbers etc., suggested NPK mixed solution such as calcium chosphite zinc liquid fertilizer, amino acid potassium polyphosphate and so so; root vegetables, such as potatoes, radishes, onions etc., suggested potassium polyphosphate, or and so on.