The prospects for Indiana's flood-ravaged grain crops recovering are becoming increasingly slim with more rain forecast over the next two weeks, according to Purdue Extension experts.
"I have been optimistic with my assessment, based on the possibility that the weather would moderate," Purdue University agronomy professor Bob Nielsen said. "But every subsequent downpour pushes a few more fields off the cliff."
Prospects are not much brighter for soybeans.
"Some plants have been in standing water for up to three weeks," soybean specialist Shaun Casteel said.
According to the U.S. Department of Agriculture Crop Progress report released Monday, 25 percent of Indiana's corn crop and 26 percent of the state's soybean crop was rated as poor or very poor.
The National Weather Service in Indianapolis reported that 16.54 inches of rain fell in the city from June 1 through July 15, making it the second highest total on record for that period. The record is 16.77 inches, set in 1875.
Waterlogged plants desperately need a stretch of dry weather to allow roots to regenerate, the Purdue Extension experts said. When the soil starts to dry out, new root growth begins near the surface.
"It is the rate and extent of that fresh root development that largely determines whether a waterlogged field will recover strongly or not," Nielsen said.
Root growth is strongest in bright sunlight and warm temperatures. Overcast or rainy conditions delay drying and threaten the recovery.
"Unfortunately, most of Indiana has not yet had a significant string of days with favorable growing conditions and so cornfield recovery has been exceedingly slow and frustrating for growers," Nielsen said.
Knowing their crops' chances of recovery is vital to farmers who are trying to decide whether to invest in an initial or additional application of potentially costly nitrogen-based fertilizer.
"It's hard to know whether you need a lot of nitrogen for these little corn plants," said soil fertility specialist Jim Camberato. "It's hard to tell if the return on investment is there."