James S. Schepers

ARS Scientist Wins Award for Soil Research

By Jan Suszkiw
February 9, 2005

National news release

WASHINGTON, Feb. 9— Agricultural Research Service (ARS) scientist James S. Schepers’ studies to prevent fertilizer from escaping into groundwater have earned him a top award from ARS, the U.S. Department of Agriculture’s chief in-house scientific research agency.

Schepers was named “Northern Plains Area Senior Research Scientist of 2004" by ARS, which will honor him and other award-winning scientists at a ceremony here today at USDA headquarters. Schepers will receive a plaque, a cash award and additional research funding. Schepers was cited for outstanding achievement in the agency’s Northern Plains Area, which includes Colorado, Kansas, Montana, Nebraska, North Dakota, South Dakota, Utah and Wyoming.

As research leader of ARS’ Soil and Water Conservation Research Unit in Lincoln, Neb., Schepers directs 27 scientists, support staff and graduate students in a range of studies aimed at developing agricultural practices that enable farmers to both protect and profit from their land’s natural resources.

More about Schepers' research: 1998 | 2000 | 2001 | 2004

Soil scientist James Schepers tests a remote sensing technique that checks for nitrogen stress in corn plants, so high-canopy sprayers "know" how much liquid fertilizer to feed the crop.

Schepers’ achievements include a two-pronged approach to managing nitrogen fertilizers to avoid overloading the soil with nitrate, a compound that, if not used by crop plants, can leach into groundwater and pollute it. The approach’s first “prong” involves detecting the onset of nitrogen-related stresses in the crop. The second prong involves remedial action, giving the crop the nitrogen it needs using management practices that protect both groundwater and the farmer’s profit margin.

To make this approach practical, Schepers led studies to develop a portable, hand-held device to measure plant chlorophyll concentrations as a measure of the crop’s vigor, or lack thereof due to nitrogen deficiencies. The chlorophyll meter’s potential became apparent in the late 1990s with the Nebraska Management Systems Evaluation Area program. The ARS-led project showed that it’s possible to curb nitrate leaching without short-changing corn yields by using fertigation, a method of applying variable rates of nitrogen in irrigation water.

Currently, Schepers is coordinating a multi-state effort to investigate automated crop monitoring. Rather than planes or satellites, this remote-sensing technology makes use of electronic sensors perched atop high-clearance crop canopy sprayers. To check for nitrogen stress, for example, the sensors zap the crop with red light, which is absorbed by chlorophyll, and then measure the amount of reflected light as an indication of plant photosynthetic activity and vigor. The canopy sprayer uses the information to dispense liquid fertilizer at variable, rather than fixed, rates of nitrogen.

In addition to his research achievements, Schepers is being honored for his mentorship of graduate students, junior researchers and foreign-exchange scientists, as well as providing technical expertise to national and international organizations.

Schepers is the leading or contributing author on 81 peer-reviewed publications. He is a member of the American Society of Agronomy, the Soil Science Society of America, the International Soil Science Society, Gamma Sigma Delta, and Sigma Xi.

Schepers earned a B.S. degree in agronomy in 1968 and an M.S. in soil chemistry in 1970 at the University of Nebraska and a Ph.D. in soil chemistry at the University of Illinois in 1973. Schepers, a native Nebraskan, joined ARS in 1975 and lives in Lincoln with his wife, Marilyn.