What are common mistakes when treating zinc deficiency?

Mistakes in zinc treatments, although common, result in reduced effectiveness and sometimes harm plant health. Adding zinc without a proper soil test usually treats an unrelated issue. Uniform rates of application overlook the unique needs of different crops. Foliar-only applications provide temporary benefits while completely ignoring root causes. The time and money spent will ultimately result in wasted resources and a longer recovery period for the crop from deficiencies and toxicity.

Lack of awareness about pH issues can be very harmful. Alkaline soils will lock up zinc above 7.0 regardless of how much you apply. You must use sulfur to correct the pH before gaining any benefits from zinc. I've seen farmers apply triple the recommended zinc amount with no response until they corrected the pH. Soil testing can prevent loss like this.

Dependency on foliar sprays is the creation of long-term chronic deficiency cycles. Foliar sprays temporarily increase zinc availability for a few weeks but do not promote long-term zinc improvement in the soil. For remediation, soil amendments need to be applied to address the root causes of the deficiency. Foliar application of zinc sulfate with compost and microbial inoculants will improve longevity.

It is best to test before you reapply to avoid toxicity issues. Soil zinc levels above 3.0 mg/kg can cause leaf bronzing and root damage, especially when applied in excessive amounts. Remember to monitor any recorded applications, including dates and rates. Avoid applying as runoff, as it may affect the environment; instead, incorporate amendments appropriately. Zinc in soil at levels exceeding 200 mg/kg can contaminate the environment.

Read the full article: Zinc Deficiency Plants: Symptoms and Solutions