SOIL CARBON AND CLIMATE CHANGE NEWS

From Kansas State University's:

Consortium for Agricultural Soils Mitigation of Greenhouse Gases (CASMGS)

http://www.oznet.ksu.edu/ctec

Charles W. Rice, K-State Soil Microbiology, National CASMGS Coordinator (785) 532-7217 cwrice@ksu.edu

Kent McMay, K-State Soil and Water Conservation Specialist (785) 532-5776 kmcvay@ksu.edu

Steve L. Watson, CASMGS Communications (785) 532-7105 swatson@oznet.ksu.edu

May 14, 2003

No. 19

This week's issue:

K-State Research:

* Economic Analysis Of Carbon Sequestration In Continuous Corn

Science:

* CO2 Allows Forests To Expand Into Dry Areas

* Measuring Global Temperatures: New Analysis To Examine Discrepancies

* NASA Satellites Create Maps Of Global Carbon Cycle

International:

* Australian Organization Agrees To National Emissions Trading Scheme

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k-state research: Economic Analysis Of

Carbon Sequestration In Continuous Corn

Research at the K-State North Agronomy Farm near Manhattan has examined the effect of tillage systems, N sources, and N rates on carbon (C) sequestration levels in non-irrigated continuous corn. The soil is a Kennebec silt loam. The economic and agronomic analysis was conducted by K-State researchers Scott Boyles, graduate student in Agricultural Economics; Jeff Williams and Michael Langmeier, professors of Agricultural Economics; and Chuck Rice, professor of Agronomy.

Specifically, the study examined the following treatments:

* Conventional tillage vs. no-till

* Ammonium nitrate vs. manure

* N rates: 0, 75, and 150 lbs N/acre

Results were analyzed from a 9-year period of treatments, 1991-1999.

Some of the questions related to C sequestration that the research addresses are:

1. Does no-till continuous corn lead to higher rates of soil C sequestration than conventional tillage continuous corn?

2. Does N source affect C sequestration?

3. What are the additional costs, if any, incurred with the adoption of soil C sequestration methods?

4. When emission levels and energy use by the different management practices are taken into consideration, does that effect the net soil C sequestration?

5. What payments, if any, might be needed to entice producers to adopt soil-sequestereing methods?

Soil samples for C measurements were taken after harvest in 1992 and again after harvest in 1999. The difference in soil C levels between these two sampling dates is determined to be the amount of C sequestration that has occurred.

The samples were taken at three depth levels: 0-5 cm, 5-15 cm, and 15-30 cm. The soil samples were only taken for the conventional and no-till tillage treatments using N rates of 0 and 150 lbs per acre, for both ammonium nitrate and manure. The 75 lb N/acre treatments were not tested for C levels.

Carbon dioxide emission levels from the various treatments were estimated. The emissions estimates were based on the energy used in field operations, the energy used in applying inputs, and the energy used in manufacturing the inputs.

To simplify the conclusions below, the following discussion includes only the comparisons of conventional-till vs. no-till and ammonium nitrate (commercial fertilizer) vs. manure at the 150 lb N/acre rate. On a practical level, the 0 N treatment is not going to be used by producers (although it is necessary for scientific comparison purposes).

In looking at C sequestration levels, the basic conclusions from this study are:

* No-till had higher C sequestration rates than conventional-till at the 150 lbs N/acre rate. The highest C sequestration rate was the no-till with manure, at 1.24 tons C per acre per year for the entire 0-30 cm depth. The next highest C sequestration rate was in the no-till with commercial N fertilizer, at 1.09 tons C per acre per year. This was followed by conventional-till, manure at 1.04 tons and conventional-till, commercial fertilizer at 1.03 tons.

* When taking CO2 emissions of the different tillage/N source systems into account (net soil C sequestration), the relationships were the same. No-till had higher net C sequestration levels than conventional-till. The highest net C sequestration rate was the no-till with manure, at 1.21 tons C per acre per year for the entire 0-30 cm depth. The next highest net C sequestration rate was in the no-till with commercial N fertilizer, at 1.03 tons C per acre per year. This was followed by conventional-till, manure at 1.00 tons and conventional-till, commercial fertilizer at 0.96 tons.

* In terms of net return (dollars per acre), no-till was greater than conventional-till averaged over the 9-year period at the 150 lbs N/acre rate. The no-till, commercial fertilizer treatment had a net return of $70.35 per acre. No-till with manure had a net return of $43.13. Conventional-till with fertilizer was $41.06 per acre, and conventional-till with manure was $22.74 per acre.

* Corn yields were about the same for no-till and conventional-till at the 150 lbs N/acre rate. Costs per acre were generally about $30 per acre lower with no-till than conventional-till.

* Carbon credit payments to encourage the adoption of no-till were not required. This is because the no-till systems had a higher soil and net C sequestration rates, as well as having higher net returns.

* Carbon credit payments were found to be necessary to encourage the use of manure as a fertilizer source compared to commercial fertilizer. For no-till systems, C credits of $18.32 per acre for year were required for adoption of manure. For conventional-till, C credits of $27.22 per acre were required.

-- Steve Watson <swatson@oznet.ksu.edu>

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CO2 Allows Forests to Expand

Into Dry Areas

Researchers at the Weizmann Institute in Rehovot, Israel recently released the results of a new study which indicate that high atmospheric carbon dioxide (CO2) levels caused by human activities could boost the expansion of forests into arid lands. According to the scientists, Israel's Yatir Forest, which was planted at the edge of the Negev Desert approximately 35 years ago, is expanding at "an unexpected rate," with a CO2-absorbing efficiency comparable to forests in "more fertile lands."

The institute said forests in dry regions typically develop "very slowly," absorbing limited amounts of CO2. However, the research team, which was led by Weizmann Institute Environmental Sciences and Energy Department professor Dan Yakir, found that the forest was "growing at a relatively quick pace and is even expanding further into the desert."

The scientists suggest that the forest is able to grow quicker because the higher CO2 levels allow trees to limit the amount they open their pores to absorb CO2 for photosynthesis. In low CO2 conditions, plants must open their pores wide to absorb more CO2, losing large quantities of water to evaporation. However, with the "30 percent increase of atmospheric [CO2] since the start of the industrial revolution," the plants do not have to fully open their pores to find CO2, allowing less water to escape and boosting growth rates.

For complete information, see: http://wis-wander.weizmann.ac.il

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Measuring Global Temperatures:

New Analysis To examine discrepancies

Using a new analysis of satellite temperature measurements, scientists from the Lawrence Livermore National Laboratory have determined that uncertainties in satellite data are a significant factor in studies attempting to detect human effects on climate.

Since 1979, Microwave Sounding Units (MSUs) have been flown on 12 different polar-orbiting weather satellites operated by the U.S. National Oceanic and Atmospheric Administration. MSU instruments measure the microwave emissions of oxygen molecules, which are related to atmospheric temperature. By monitoring microwave emissions at different frequencies, it has been possible to ‘back out’ information on temperature changes in various layers of the atmosphere.

Until recently, only one group — from the University of Alabama at Huntsville — had analyzed the raw MSU data. This analysis is complicated by such factors as the gradual decay and drift of satellite orbits (which affect the time of day at which MSU instruments measure atmospheric temperatures) and by problems related to the calibration of MSUs.

The pioneering Huntsville analysis of the MSU data suggested that the troposphere (the lowest layer of the atmosphere) had undergone little or no overall warming since 1979. Some have used this finding to question both the reality of human-induced global warming and the reliability of computer climate models, which predict that the troposphere should have warmed in response to increases in greenhouse gases.

The Huntsville results are also at odds with thermometer measurements indicating pronounced warming of the Earth’s surface during the satellite era.

Now a second group has conducted an independent analysis of the same raw MSU data used by the University of Alabama scientists. This group, led by Carl Mears, Matthias Schabel, and Frank Wentz of Remote Sensing Systems in Santa Rosa, uses different methods to correct for satellite orbital drift and MSU calibration problems. They find that the troposphere probably warmed by roughly 0.1 degrees Celsius (0.18 degrees Fahrenheit) per decade from 1979 to 2001. This amounts to a total rise in tropospheric temperature of 0.4 degrees Fahrenheit over this period.

For complete details, see: www.llnl.gov/llnl/06news/NewsReleases/2003/NR-03-05-01.html

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NASA Satellites Create Maps

of Global Carbon Cycle

NASA's Goddard Space Flight Center (GSFC) recently unveiled a series of maps that utilize space-based measurements of plant properties collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) and other surface-based measurements to produce regularly updated composite maps of the Earth's "net primary production," a calculation of the amount of carbon dioxide (CO2) absorbed by vegetation minus the amount produced as a result of respiration.

"We now have a regular, consistent, calibrated and near-real-time measure of a major component of the global carbon cycle for the first time," said University of Montana Numerical Terradynamic Simulation Group director and MODIS science team member Steve Running. "This measure can also be the basis for monitoring the expansion of deserts, the effects of drought, and any impacts climate change may have on vegetation growth, health and seasonality."

GSFC said the new maps demonstrate that the highest mid-summer productivity rates are found at temperate latitudes with mild climates and not at tropical latitudes. However, the center noted that tropical forests are "more productive over a full year because of their longer growing season."

For complete details, see: http://www.gsfc.nasa.gov/goddardnews/20030425/carbon.html

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Australian Organization Agrees To

National Emissions Trading Scheme

The Australian Chamber of Commerce and Industry (ACCI) recently announced it has agreed to accept the trading of greenhouse gas (GHG) emission credits as a method of helping combat global warming in light of the federal government's rejection of the Kyoto Protocol.

"At its latest meeting in March 2003, ACCI General Council agreed to support, in principle, emissions trading as an option to abate greenhouse gases," said ACCI chief executive Peter Hendy, noting that ACCI also opposes carbon taxation.

According to federal officials, the Government/Business Climate Change Dialogue, which initially commenced last year, met earlier this week with senior Australian ministers to discuss alternative emission reduction solutions.

-- The West Australian, April 14, 2003

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MEETINGS OF INTEREST

Note: All dates are 2003 unless otherwise noted.

May 27-30

The Fourteenth Global Warming International Conference & Expo (GWXIV)

Boston, Massachusetts

For more information, contact Global Warming International at (630) 910-1551

October 16-17

CASMGS Carbon Measuring and Management Forum

Manhattan, Kansas

For more information, contact Scott Staggenborg at (785) 532-5833

Send comments or items for the newsletter to Steve Watson at:

<swatson@oznet.ksu.edu>

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