BLOOMINGTON, Ill. — The severe drought of 2012 prevented the Illinois corn crop from fully utilizing plant-available nitrogen due to lack of water and extreme heat.

In an effort to inventory and track the unused nitrogen in the soil remaining after harvest and determine best management practices to address this residual nitrogen, the Illinois Council on Best Management Practices launched a new soil testing program called N-WATCH.

Working in conjunction with University of Illinois Extension crop production specialist Emerson Nafziger, the council provided training to ag retailers and farmers on the N-WATCH procedures and importance of the program.

The industry responded and took more than 300 N-WATCH soil samples throughout the state following the 2012 harvest. The council, with funding assistance from the U.S. Department of Agriculture’s Natural Resources Conservation Service, paid the cost of the shipping and analysis of the soil samples.

Nafziger’s summary of the data collected from the fall sampling effort can be found online at http://bulletin.ipm.illinois.edu/?p160.

Samples collected after harvest revealed that the remaining nitrate still was in the upper soil profile and potentially available for the 2013 corn crop.

However, with recent rains, N-WATCH samples collected in March and April now show a significant amount of the drought-related residual nitrate has moved deeper into the soil, making it unavailable to the 2013 crop and susceptible to loss. As a result, there is increased potential of elevated nitrate levels in water.

To provide timely information about nutrient movement, the council shared the N-WATCH results with the ag industry, the Illinois Environmental Protection Agency and the Illinois Department of Agriculture.

In addition, the council recently hosted a webinar to discuss the results with water supply officials in priority watersheds in central and eastern Illinois.

“The N-WATCH program is a new tool and gives ag retailers and farmers the ability to estimate plant-available nitrogen and adjust application timing and rates accordingly to minimize environmental impact and maximize nitrogen efficiency,” said Mike Plumer, CBMP coordinator.

The Illinois Council on Best Management Practices represents the combined efforts of Illinois Farm Bureau, the Illinois Corn Growers Association, the Illinois Soybean Association, the Illinois Fertilizer and Chemical Association, the Illinois Pork Producers Association and Syngenta Crop Protection.

For information about how to participate in N-WATCH, contact local ag retailers or phone (309) 827-2774.