Soy farmers on the ground in Northern Iowa and Southern Minnesota report heavy flooding and subsequent crop loss. After almost 11 inches of rain, several farms near Rock Valley, Iowa have a few hundred acres of cropland under water. Flooding can affect crop growth, nitrogen retention in the soil, and the likelihood of soil-borne diseases like pythium and phytopthera. Industry sources estimate that 300 to 500 thousand acres of predominantly soy fields could be lost.
One farmer from Minnesota reports on Agweb :
“Too much water sucked all the nitrogen thru [sic] the ground….Worst crops in the 15 years or so...still water standing all over in this area. I anticipate a 10 to 15% reduction against trend line yields…. I think yields will surprise in a very negative way.”
We can track the NDWI (Normalized Difference Water Index) through our Kernel web application. NDWI is not just a representation of weather patterns; rather, it is a metric derived from satellites that represent plant water content and indicates plant water stress.
In the visuals below, we can see an increase in NDWI (in blue) over the past three weeks in Minnesota:
NDWI (Normalized Difference Water Index) for Minnesota on 7/1/18. Half the state is normal to dry, and half is wetter than average. (Source: Kernel)
NDWI (Normalized Difference Water Index) for Minnesota on 7/8/18. The dry portion of the state is now saturated. (Source: Kernel)
NDWI (Normalized Difference Water Index) for Minnesota on 7/16/18. The entire state continues to be saturated with a high water content. (Source: Kernel)
The graph in each image shows a steady increase in NDWI levels from 5/28/18-7/16/18.
If the trend holds, it could lead to crop losses and/or diseases. While we can’t share specifics, our models suggest soybean yields in the US below 50 bu/ac.