Mar14MonMarch 14, 2016
When crops aren’t performing because of lack of nutrients, nitrogen, phosphorus and potassium receive all of the attention, but they aren’t always the remedy.
Last year, one particular field comes to mind. I had the “opportunity” to look at a crop that was chlorotic in appearance. The farmer informed me that this was a perennial problem and consultants often informed him that he needed more nitrogen. We implemented a sampling program to see if we could learn more. Tissue samples did not reveal an obvious suspect, but soil samples told a different story. Likely suspects were multiple micronutrients. The field was extremely low in Zn, Mn, Fe, and Cu!
Micronutrient deficiencies are likely when one of the following conditions apply:
- Removal of large amounts by high yielding crops.
- Leaching from sandy soils.
- Naturally high pH soils.
- Overlimed soils resulting in a high pH.
- Land leveling.
- Additions of high rates of phosphorus.
- Soil compaction.
- Cool, wet growing conditions.
- Tie-up by the soil.
- Use of sensitive crop varieties.
Although plants need a much smaller quantity of micronutrients than N, P, K, their importance is still great. A shortage of micronutrients can limit plant growth and crop yields. In most crops, micronutrient uptake is greatest before the plant begins to flower. Therefore, it is logical to apply micronutrients at planting to get maximum utilization.
A representative soil sample can give a good indication as to whether a micronutrient deficiency may occur.
-Wayne Becker, Southern US Sales Agronomist