• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Sensors Cast Light for Nitrogen Use

Posted on: Sunday, 14 August 2005, 03:00 CDT

Using the right amount of nitrogen fertilizer to obtain desired corn yields can be a challenge for both economic and environmental reasons.

University of Missouri (MU) researchers are using sensors called light emitting diodes (LEDs) to accurately measure the color of young corn and apply rates of nitrogen according to plant needs.

The researchers are in their second year of testing this technology on Missouri farms. They hope this LED approach will not only increase profits for Missouri producers, but also create a healthier environment including in the Gulf of Mexico where nitrogen runoff carried by the Mississippi River has created hypoxia.

Nutrients such as nitrates and organic nitrogen promote rapid growth of tiny plankton in coastal waters, which then decay and in the process consume oxygen. The resulting low oxygen levels in the water are called hypoxia. Hypoxia stresses or kills bottom-dwelling creatures on which the region's seafood industry depends.

In this research, what has historically proved to be an ample amount of nitrogen used by the farm operator is applied in early spring to only one area of the field. LED devices mounted on a fertilizer applicator measure light reflected from small corn plants in this area, providing a baseline point. The computer-equipped applicator then applies nitrogen fertilizer to the rest of the field. Variable rates of nitrogen are applied to the crop depending on the color or reflective value of corn leaves detected by the LEDs compared to reflectance from amply fertilized corn. Corn that looks similar to the amply fertilized corn means that there is a good nitrogen supply coming from the soil in that area.

Variable rate sidedressing demonstrations last year saw a 33-lb/ acre reduction in nitrogen compared to rates used by producers in the same fields, says Peter Scharf, MU nutrient management specialist.

For more information, contact Scharf, 573-882-0777, scharfp@missouri.edu.

Copyright American Society of Agricultural Engineers Aug 2005

Source: Resource

More News in this Category