However, there were less than 10 people out of the 300 person audience who raised their hands to indicate they've seen tiles running somewhere in Iowa this winter. "So way less than 10% of the tiles in Iowa are running," says Taylor. "When I asked that question a year ago at this time, it was about 50%. And usually, in most years about 80% of the tiles are running at the end of February or beginning of March."
Looking beyond spring, what if subsoil moisture reserves aren't fully recharged going into 2013 growing season? What are the odds that Iowa and other dry areas in the western Corn Belt will get enough rain and get it on a timely basis during the growing season to make up for the lack of reserve subsoil moisture?
Without subsoil moisture, it'll be difficult to get a near-record crop yield in 2013
In other words, with low levels of subsoil moisture, what are the chances of getting enough timely rain events during the growing season to carry crops through to a good harvest? "That has happened before, as we look back at weather history in Iowa," says Taylor. "In western Iowa it's happened only once in 60 years. To receive enough rain as we go through the 2013 growing season to get a near record high crop yield without much soil moisture -- that would be very difficult to do in western Iowa especially. But in eastern Iowa it does happen more often."
You might not have much soil moisture in the driest one-third of Iowa, the situation a lot of places in western Iowa are in right now. And if they get timely rains during the growing season they end up with a fairly good yield, maybe 20% of the time, says Taylor. But they also end up with a crop disaster more than 20% of the time. "So this weather and crop yield outlook for 2013 is unsure for the eastern part of Iowa and just bad news for the western part of the state," he adds.
If Iowa has a dry spring, crops will need good, timely rains during 2013 growing season
"We can't say we're not going to get timely rains. But we are saying rains which occur on such a timely basis only happen rarely," says Taylor. "In Iowa, we rely on having a bank of moisture stored in the soil as a reserve for crops. So when that two week long hot dry period comes in summer, which it almost always does for a week or two, crops can draw moisture out of the subsoil reserve to carry them through the dry period. And if the moisture isn't there, crops can lose yield in a hurry when it turns hot and dry and they don't have reserve moisture to draw on from deeper in the soil."