Extension Ag Update
September/October 2002
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Research

Nutrient and Pesticide Loads in Subsurface Drainage from Organic and Conventional Cropping Practices

Scientist: Gregory McIssac, University of Illinois, 217-333-9411, gmcisaac@uiuc.edu
Source: North Central Region SARE Field Notes, July 2002

The primary objective of this project was to quantify and compare the concentration and loads of nitrogen, phosphorus and herbicides in subsurface drain effluent from certified organic and conventional corn-soybean cropping practices used in central Illinois. We detected significantly lower concentrations of nitrate, chloride and atrazine in the water draining from organically managed fields. Concentrations of other constituents were not statistically different across farming systems. Differences in nitrate concentrations were greatest when the organically managed fields are in a forage/ green manure crops at which time concentrations in drainage water from organically managed fields average approximately 2 mg N/L while concentrations in drainage from conventionally managed fields range from 10-20 mg N/L Nitrate concentrations in drainage water from the organically managed fields increased when the green manure crops were incorporated into the soil and row crops are grown. In most instances these concentrations have been less than the concentrations in the drainage water from conventionally managed fields, but in 1999 there was a significant exceptions to this tendency in one field. Data collected in the project are being used in projects focused on modeling nutrient transport and transformation processes and economic analysis of strategies to improve water quality in agriculture watersheds.

U of I Students Solve Problems for Illinois Industry

Scientist: Doug Bosworth, Dept. of Ag. Eng., Urbana, 217-333-8355, dlb@age.uiuc.edu
Source: Leanne Lucas, College of Aces/ITCS Urbana, 217-244-9085, llucas@uiuc.edu

Leave it to a team of University of Illinois seniors to solve a problem that has dogged specialty crop growers for some time. Students found a way for growers to switch between serrated wear strips and smooth wear strips on a John Deere STS combine in only 20 minutes--considerably faster than the one to one and a half hours it had been taking. Specialty crop growers, such as popcorn and edible bean growers, use the smooth wear strips to reduce crop damage. Solving such real-life problems is part of the appeal of the senior design class in the U of I's Department of Agricultural Engineering--the capstone design course for Off Road Equipment Engineering and a requirement for engineering accreditation.

"Students work harder on this three-hour course than on any course they have in college," said Doug Bosworth, adjunct professor and coordinator of the popular design class. "But they enjoy it more because they're working on real-life problems. They work with companies like John Deere, Caterpillar, Case-DMI. It gives them excellent preparation for industry." Katie Yagow, part of the four-person team that worked on the wear strip problem, agrees. "Many of our engineering classes are very theoretical and abstract. We're given problems out of a book and have nothing tangible to attach the problem to. This class is the complete opposite.

"I give them complete control of their projects," Bosworth said. "I expect them to do the necessary research, develop design alternatives, do the actual design, fabricate the parts, evaluate the parts, write formal reports, and in the end, present an industry style report to the sponsor, along with a 20-minute Power Point presentation at the sponsor's location." Students are also required to develop and track project schedules and budgets, and give their sponsors weekly project reports and monthly project reviews.

Meanwhile, the companies involved enjoy considerable benefits as well. Industry partners pay out-of-pocket costs and furnish parts, expertise and components. Bosworth estimates this expense runs somewhere between $2,000 and $2,500. In return, sponsors receive an optimum design solution to their problem, a working prototype and over 400 hours of engineering resources. The most telling endorsement of the design course came this spring when the John Deere Foundation provided the Department of Agricultural Engineering with a grant to support the instructor's position for the senior design class.

Iowa Fields Are Focus of Moisture Detection Experiment

Scientist: Jerry Hatfield, Plant Physiology, Nat. Soil Tilith Lab, 515-294-5723, hatfield@nstl.gov
Source: Luis Pons, ARS News Service, (301) 504-1628, lpons@ars.usda.gov

Corn and soybean fields in central Iowa are being viewed from land, sky and space from June 17 through July 12 as part of a soil moisture-detection experiment that compares computer-generated meteorological models to real conditions. According to Agricultural Research Service hydrologist Tom Jackson, Soil Moisture Experiments in 2002 (SMEX02) marks the first time satellites are providing soil moisture data. It is also testing sensors aboard Aqua, a National Aeronautics and Space Administration (NASA) satellite launched in May that collects information on Earth's water cycle. SMEX02 involves ARS, the U.S. Department of Agriculture's main scientific research agency, as well as NASA, the National Oceanographic and Atmospheric Administration (NOAA) and numerous universities.

The National Soil Tilth Laboratory (NSTL) in Ames, Iowa, and the Hydrology and Remote Sensing Laboratory in Beltsville, Md., are the ARS entities taking part in SMEX02. More than 50 researchers, including ones from Japan and Canada, are participating, according to NSTL director Jerry Hatfield. The goal is to verify moisture values given by weather models by comparing them to actual readings gathered from Earth's surface; airplanes at various altitudes; and NASA, NOAA and European Space Agency satellites. Soil moisture greatly influences summer precipitation over the central United States and is key in predicting seasonal weather patterns. Improving computer models' abilities to predict its movement will improve weather forecasting.

Sensors aboard five aircraft will get readings at altitudes ranging from 25,000 feet down to 100 feet. On land, researchers in 78 fields will measure changes in soil water in the upper four inches of terrain. Many instruments have been placed around Kelley, Iowa, including Light Detection and Ranging (LIDAR), which is similar to Doppler radar and can measure moisture movement across whole fields. According to Hatfield, this experiment may provide new understanding of how cropping-system management in the Midwest can influence weather on a large scale.

Alfalfa as a Fuel--and a Plastic?

Scientist: Deborah A. Samac, Research Plant Pathologist, Univ. of Minnesota, ARS, 612-625-1243, debbys@puccini.cdl.umn.edu
Source: ARS News Service, USDA, Source: Don Comis, (301) 504-1625, comis@ars.usda.gov

U.S. Department of Agriculture bioenergy funds are being used to convert alfalfa into the first dual-use biofuel plant. The leaf serves as a factory for raw, biodegradable plastic beads, other industrial products or better livestock feed, while the stem goes to ethanol production. JoAnn Lamb, a plant breeder who serves on a team of five scientists at the Agricultural Research Service's Plant Science Research Unit in St. Paul, Minn., has created the "parents" for new alfalfa varieties by crossing European varieties with unusually thick stems with modern alfalfa varieties developed for dairy feed. The thick stems provide more raw material for ethanol production. Team member Deborah Samac, an ARS plant pathologist, has transformed alfalfa so it can manufacture plastic. The process isn't practical yet, but it could be, if a cell wall barrier could be prevented from trapping beads of plastic.

With the USDA funding, ARS animal scientist Hans Jung will develop tests to screen alfalfa plants to find those with the most sugar and starch in their stems and the most digestible fiber. These types of stems would provide more material for conversion to ethanol by fermentation microbes. Besides plastics and fuel, alfalfa may be a renewable resource for replacing other petroleum-based products and nonrenewable resources, such as nitrogen and phosphorus fertilizers. Carroll Vance, team member and unit research leader, has isolated many genes for creating new varieties, including one that helps alfalfa fix more nitrogen from the air and take in more phosphorus. Because alfalfa absorbs nitrogen from deep in the soil, ARS soil scientist Michael Russelle sees a major role for alfalfa in preventing fertilizer from polluting water