For my Masters degree, I found myself smack dab in the middle of Kansas, working on a degree in Soil Fertility.
Had I heard of Iron Deficiency Chlorosis? Nope!
Did I know anything about Kansas? It was flat?!? (It isn’t BTW)
In Kansas, the soils are actually deficient in iron. This is a huge problem for plants, as they rely on iron for production of chlorophyll. Without adequate supply, upper leaves start turning yellow. If the situation is not improved, the plants yield poorly, and can even die. This is especially problematic in soybeans. What causes chlorosis is very complex, as iron interacts with many different nutrients, as well as moisture levels. However, high pH is almost always necessary.
That being said, it was my job to test the performance of iron seed coating and foliar iron application on soybean varieties, some of which were resistant to chlorosis, and some that were more susceptible to chlorosis.
- Using a foliar iron spray did not generate any positive benefits.
- Having a seed coating improved chlorophyll meter (SPAD) readings by 14% overall.
- The tolerant variety had 9.5% higher (they were greener) chlorophyll meter readings than the susceptible varieties
- For plant height, the susceptible variety responded better to seed treatment than the tolerant variety (increasing 19 cm vs. 12 cm for the tolerant variety).