This is Dr. Nathan Mueller, your local agronomist for Nebraska Extension. Last week I discussed management practices to alleviate iron deficiency chlorosis in soybeans. Visit croptechcafe.org to listen to last week’s radio message. Zinc deficiency in corn is the other main micronutrient deficiency concern in the area.
Zinc deficiency in corn occurs more frequently in four settings in East Central Nebraska:
- On eroded hillsides
- On calcareous soils where small white rocks are visible at the surface
- Where soil has been moved for terraces
- Or on very sandy soils with low organic matter.
Zinc deficiency symptoms are more likely to be visible under cool, wet conditions in May and early June. Symptoms of zinc deficiency can be seen on newer leaves of corn plants. Classic symptoms include white to pale yellow broad bands on either side of the midrib beginning at the base of the leaf (Figure 1).
A zinc DPTA soil test is a great way to decide the need for fertilization. Soil test values less than 0.8 ppm warrant fertilizer application. However, soil test zinc values are not uniform across the field and lower values occur more frequently in certain settings as I mentioned. Soil sampling by management zones is one way to capture some of that variability and apply zinc fertilizer where it is needed most.
There are various application methods and Zn fertilizer products to consider. It is important to consider the solubility, the cost, the ease of application, and the lasting effects. Often the most practical way to build and maintain a high level of zinc availability for your corn crop is through broadcast application of zinc sulfate.
To learn more about zinc deficiency in corn, call me at 727-2775 or visit our local website at croptechcafe.org. Know your crop, know your tech, know your bottom line. This is Dr. Nathan Mueller, your local agronomist for Nebraska Extension on KTIC radio.
Read more about zinc deficiency in corn at NebGuide G1830: Micronutrient Management in Nebraska