May has been both warmer and drier than normal all over Illinois. While the low rainfall levels continue to be a source of concern, most of the fields where the roots are tapping well into the soil water have reasonably uniform growth and good crop color.
Other benefits of the dry May weather is near-total absence of drowned-out areas of fields and almost none of the excessive nitrogen losses that have followed wet spring weather in recent years. Soil conditions remain conducive to deeper rooting, and this could provide real benefits if dry conditions occur later in the season. The frequencies of some plant diseases that require wet weather to develop have also been reduced.
“On balance, the warm, dry weather has been favorable, and we do not believe that there has been any substantial loss of yield potential in most areas up to now,” Nafziger concluded, though he notes that some of the crop has not been able to establish a good root system yet and remains under stress. “When we reach the point where current soil water supplies will no longer provide water at rates high enough to sustain maximum growth rates, the need for rainfall will become more urgent.”