I had some corn earlier in this season that had interveinal chlorosis. It seemed like it was on the new leaves so I thought at first could be an Iron or Manganese deficiency.  I checked the soil test and we had the desired levels of Iron and Manganese but our pH was 7.2.  At pH 7.5 Iron and Manganese are hard for plant to access. Someone else looked into this and pointed out that it was probably Sulfur since there was only 5ppm (missed that one!).  I had applied Sulfur in the spring to remedy that but perhaps since it was the granulated form it wasn't very plant available by the time the corn needed it.

So in order to test the hypothesis that it was indeed sulfur that was deficient I applied a foliar solution to the leaves of certain plants.  If sulfur was the deficient nutrient than the interveinal chlorosis would improve after some time.  Unfortunately elemental sulfur is hydrophobic and I didn't have any wettable sulfur so I used Iron sulfate, Zinc sulfate and Manganese sulfate, thinking that if all three worked it would be clear that sulfur was deficient, and if only one resolved the chlorosis then that would be the deficient nutrient.

I would say in general all the corn looks better, but the corn I treated with Iron sulfate didn't show as much dramatic change and I think this might be because it was quite chunky and hard to break up into a powder to get a good solution.  The Manganese sulfate and Zinc sulfate treated corn had a much clearer change.  You can see the two plants where I applied Manganese sulfate in the pictures. Interestingly the old leaves didn't seem to recover that well compared to the new leaves which might point again to the nutrient deficiency being Sulfur since S can be mobile when there is sufficient N.

Corn with Manganese sulfate applied foliarly at 10g/L at Day 1, Day 8 and Day 15

Think of the most iconic breakdown of a state, the most classic revolt of a people against the existing power structure. For many, the French Revolution immediately comes to mind.  Clearly this was a complex event with many factors, but if one were to simplify its causes, wheat is what brought the downfall of the French monarchy.  Wheat harvests had been poor since the 1783 volcanic eruption of Mt. Laki in Iceland and exceedingly harsh winters in 1788 and 1789 had further decimated the wheat crop.  Over the course of 1879, the price of bread rose 67% from 9 sous to 15 sous.  The average French worker was earning 15 to 30 sous a day. In order to afford the two loaves of bread needed to feed a family of four, the worker would then be spending 100-200% of their income on food.


It seems that when more than 40% of income is spent on food social unrest is likely.  Other factors such as a highly extractive government or perceived corruption will help to ensure that this turmoil is aimed at replacing the current state.  So in the case of late 18th century France, with 100-200% of income spent on food and heavy taxes being levied by a corrupt elite to fund a lavish lifestyle, a dramatic revolution seems natural.






Would this revolution have happened had there been a bountiful wheat harvest? Or if French farmers had adopted alternative crops like the potato and food prices remained stable?  I for one do not think so.  It's possible to aruge it was worthwhile in the long run to have these food shortages since it ended feudalism in France, but the point is that agronomy had a direct impact on the direction of the French nation.



Eventually I hope to explore this connection between the stability of nations and their agricultural practices in greater detail.  It is a connection that plays out not only in history but across the headlines of today's news.  Amongst the chaos and violence of a collapsing of nation, it is easy to forget the farmer in his field and the quiet events that preceded these dramatic political convulsions.  But we must fully appreciate how much power the farmer and the soil that he works truly have.  To not apreciate that soil is of the utmost importance to a state is a grave folly.  As Alexandre Dumas (might have) said, "No society is more than three meals away from revolution."