SOIL-PLANT-NUTRIENT SOIL-PLANT-NUTRIENT RESEARCH UNITRESEARCH UNITFORT COLLINS, COLORADOFORT COLLINS, COLORADO

1957: Dr. Omar Kelly began a new laboratory in Fort Collins to study the decline of carbon & nitrogen in Great Plains Soils. This laboratory became known as “The Nitrogen Laboratory”.

Hired into The Nitrogen Laboratory were Drs. Francis Clark and Lynn Porter as well as Bill Beard and several graduate students including Bobby Stewart and Ray Jackson.

Dr. Clark coined the termand described “chemo- denitrification”.

Dr. Clark’s work was first to use a gas chromatograph to measure gaseous denitrification products.

Drs. Porter, Stewart, Jackson, and Kemper published the first paper using a chloride tracer to study counter-diffusion of Cl- and NO3

- ions in soil.

After the 1960 elections, ARS was reorganized and Omar Kelly’s leadership team was dispersed. Dr. Frank Viets, of that team, was named as Leader of the Nitrogen Laboratory.

1963-1964: The Rachel Carson era began, new money was received, and studies of chlorinated pesticide degradation insoil resulted.

1964: Dr. Wayne Guenzi was hired. He found that DDT degraded aerobically to DDE and anaerobically to DDD.

1968: Arvin Mosier completed M.S. degree and found that UV light photo-chemically degraded DDT.Photomicrograph of DDT crystals

DDT

1966: Gordon Hutchinson began working with Bobby Stewart on the “core drilling” project to study profile-nitrates in the South Platte River Valley.

The 129 study sites included grasslands to feedlots. Nitrate was low & uniformly distributed under grass and alfalfa.

Under dryland wheat nitrate had accumulated and

under feedlots (to 20 ft.) there was between

0 to 5000 lbs/ac.

1966-present: Unit scientists become national/internationalleaders with N and C tracers andIsotope Ratio Mass Spectrometryto quantify N-cycling and soil-Cin agricultural systems.

1970: EPA funding for feedlot pollution research in 2 climatic zones; northeast CO and eastern NE.

1972: Drs. Fred Norstadt and Art Batchelder join the Research Unit at about this time.

Besides the N-leaching, feedlot studies found significant amounts of NH3, amines, and fatty acids contributed to surrounding surface waters, soils and the atmosphere.

1974: Dr. Lynn Porter is named Laboratory Director. Unit name is changed to the “Pollution in Soil-Water-Plant Systems Unit”.

1975: Paper by McElroy indicates stratospheric ozone destruction and increased UV radiation may result from N2O emissions from N-fertilizer use.

1976: CAST report concluded there was inadequate data about N-fertilizers and N2O .

1981: Drs. Hutchinson and Mosier publish first paper on ‘chamber’ method (now used worldwide) for measurement of gaseous denitrification products and greenhouse gas fluxes from soils.

1977 -- Dr. Jim Hunter hired to research biological N-fixation.

1991 -- Patent of Bradyrhizobium japonicum mutant. Between 1995 to 2004 -- Mutant was used to inoculate over 35 million acres of soybeans and resulted in soybean yield increase worth over $250 million in farm income .

1979 -- Animal Waste Research Report No. 6 (i.e. the Manure Manual) published.

Livestock feedlot research completed with retirements of Drs. Fred Norstadt and Art Batchelder after 1988.

1986 -- Unit name changed to “Soil-Plant-Nutrient Research Unit”; Ronald Follett becomes RL; water quality (groundwater-nitrate) research program begins.

1989 & 1991: N-management books and Marv Shaffer’s NLEAP computer model are published.

In 2001 Book on N in the environment is also published.

1992 -- CAST report entitled, “Preparing US Agriculture for Global Climate Change” published for USDA and IFCC in Rio. Dr. Follett was a coauthor. Emphasis given to greenhouse gases (N2O, CH4, and CO2) and to soil-C sequestration.

1992 -- Dr. Jorge Delgado hired and begins research on global climate change with Dr. Mosier.

1996 – In collaboration with the Range Resources Research unit and CSU, open-top Chambers are established to study the effects of elevated CO2 levels on rangeland systems in relation to Global Climate Change.

1996 – present: Dr. Delgado assumes lead for groundwater quality, nitrogen management & cropping systems research in San Luis Valley of south central CO.

Research shows ‘winter cover crops’ & rotations with deep rooted crops help protect soil and water quality, sequester C, mine nitrate from underground water (and the scavenging deep profile N). The impact is the large saving of nutrients from deep leaching and also the off-site transport of nutrients and sediments into streams.

1997 -- Dr. Ardell Halvorson joins research unit to initiate no-tillage research under irrigation in eastern CO and N-management research in the Arkansas river valley.

Drs. Ardell Halvorson and Arvin Mosier conduct joint research on irrigated plots established in 1999 to address the effects of no-till vs. conventional tillage on greenhouse gas emissions from soil with flux measurements beginning in spring 2002.

1998 – Dr. Follett with post-doc Dr. Marlin Eve, in collaboration with CSU, become heavily involved in preparing national inventories of soil carbon stocks for USDA and other US Government agencies.

Forest (managed

only)27%

Cropped lands23%

Grazing lands38%Wetland

2%

Other (incl. urban, water,

etc.)10%

1998 to Present: Inventory soil carbon stocks as affected by land use and land use change in the United States.

Land Use

Forest (managed only)

46%Cropped lands

16%

Grazing lands27%

Wetland6%

Other (incl. urban, water,

etc.)5%

Carbon Stocks

SPN Unit has a major role in the soil organic carbon research in USDA by:

• Developing reliable methods to measure soil carbon

• Identifying ways to estimate soil carbon at various scales (ranging from individual fields to the entire US)

• Determining how environmental conditions and land management practices affect the rate of carbon sequestration and exchange of greenhouse gases between the atmosphere and the land.

A BRIEF ENCAPSULATION:1957: Carbon (C) & nitrogen (N) studies in Great Plains soils.1963-1964: Rachel Carson era, chlorinated pesticide degradation in soil.1966: “Core drilling” for profile-nitrates in South Platte valley.1966 – present: N & C isotope mass-spectrometry research. 1970: Feedlot pollution research.1976: N-fertilizer/ N2O emission effects on stratospheric ozone and UV radiation.1977: Biological N-fixation. Patent in 1991 on Bradyrhizobium1981 – present: Chamber method to measure soil gas flux1986: Groundwater-nitrate research emphasized; 1989, 1991 (including NLEAP model), & 2001 N books published.1992 – present: Global change/greenhouse gas research including soil-C Sequestration.1996 – present: Soil & nutrient management research1997– present: No-tillage research under irrigation. 1998 – present: National soil carbon inventories/assessments.2004 – Research is on Global Change & Soil Management.

Global Climate Change

Current research thrusts:

Soil & Nutrient Resources Management