Progress 10/01/01 to 09/30/05
Outputs
Managing agricultural systems to optimize soil organic carbon (SOC) storage and minimize nitrous oxide (N2O) emissions can impact future concentrations of greenhouse gases, CO2 and N2O, in the atmosphere as well as the sustainability of irrigated cropping systems. Nitrogen fertilization is essential to maintaining economical crop yields, but excessive N application increases N2O emissions which can offset gains in SOC storage. Irrigated crop management systems need to be developed that will increase SOC storage and decrease N2O emissions, thus, decreasing the net global warming potential (GWP). The impact of management on GWP, crop production, and greenhouse gas intensity (GHGI) in irrigated agriculture is not well documented. A no-till (NT) cropping systems study initiated in 1999 on a clay loam soil in northeastern Colorado to evaluate SOC sequestration potential in irrigated agriculture was used in this study to make trace gas flux measurements for 3 yr to
facilitate a complete greenhouse gas accounting of GWP and GHGI. Fluxes of CO2, CH4 and N2O were measured, using static, vented chambers, one to three times per week, year round, from April 2002 through October 2004 within conventional till (CT) continuous corn and NT continuous corn plots and in NT corn-soybean rotation plots. Nitrogen fertilizer rates ranged from 0 to 224 kg N/ha. Methane fluxes were small and did not differ between tillage systems. N2O fluxes increased linearly with increasing N-fertilizer rate each year, but emission rates varied with years. CO2 efflux was higher in CT compared to NT in 2002 but was not different by tillage in 2003 or 2004. Based on soil respiration and residue C inputs, NT soils were net sinks of GWP when adequate fertilizer was added to maintain crop production. CT soils were smaller net sinks for GWP than NT soils. The determinant for the net GWP relationship was a balance between soil respiration and N2O emissions. Corn grain yields increased
with increasing N rate, but soybean grain and residue yields did not. Corn residue increased with increasing N rate with no difference in residue production between tillage systems. Trends were for SOC to be increasing in the NT systems but remaining fairly constant in the CT system. Based on SOC sequestration, only NT soils were net sinks for GWP. Both estimates of GWP and GHGI indicate that when appropriate crop production levels are achieved, net CO2 emissions are reduced. The effects of crop rotation, tillage system, and N fertilization on net GWP under irrigated conditions were used to verify the DAYCENT ecosystem C, N and trace gas model output for irrigated agriculture. The results suggest that economic viability and environmental conservation can be achieved by minimizing tillage and utilizing appropriate levels of fertilizer. Additional publications will result from this work.
Impacts
Converting irrigated cropland from an intensively tilled to a no-till production system increased soil organic carbon (SOC) sequestration, but generally had little effect on carbon dioxide (CO2), nitrous oxide (N2O) or methane (CH4) emissions. N2O emissions increased with increasing N rate, but CO2 and CH4 emissions were not affected. The increase in SOC storage with NT helps offset N2O emissions from N fertilization needed to optimize crop yields and economic returns compared with the intensively tilled system, thus reducing global warming potential.
Publications
- Liebig, M.A., G.E. Schuman, D.A. Martens, and A.D. Halvorson. 2005. Managing greenhouse gas emissions in semiarid agroecosystems. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
- Halvorson, A.D., A.R. Mosier, C.A. Reule, and Walter C. Bausch. 2006. Nitrogen and tillage effects on irrigated continuous corn yields. Agron. J. 98:(Jan-Feb issue, in press).
- Liu, Xuejun J., Arvin R. Mosier, Ardell D. Halvorson, and Fusuo S. Zhang. 2006. The impact of nitrogen placement and tillage on NO, N2O, CH4, and CO2 fluxes from a clay loam soil. Plant and Soil (In press, accepted Sept. 6, 2005)
- Mosier, A.R., A.D. Halvorson, C.A. Reule, and X.J. Liu. 2006. Net global warming potential and greenhouse gas intensity in irrigated cropping systems in northeastern Colorado. J. Environ. Qual. (in Journal editorial review, Oct. 19, 2005)
- Halvorson, A.D., Mosier, A.R., and Reule, C.A. 2004. Nitrogen and crop management influence irrigated crop yields and greenhouse gas emissions. In Proc. of 2004 Great Plains Soil Fertility Conference. Denver, CO, March 2-3, 2004. Alan Schlegel (ed.), Kansas State University, Manhattan and Potash and Phosphate Institute, Brookings, SD. 10:21-27.
- Halvorson, A.D., A.J. Schlegel, A.R. Mosier, and C.A. Reule. 2004. Crop residue carbon and nitrogen returned to the soil in irrigated cropping systems. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
- Mosier, A.R., A.D. Halvorson, C.A. Reule, and X.J. Liu. 2004. Impact of tillage and N-fertilization on trace gas exchange in irrigated corn in northeastern Colorado. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
- Del Grosso, S.J., A.R. Mosier, W.J. Parton, and D.S. Ojima. 2004. DAYCENT model analysis of past and contemporary agricultural soil N2O and net greenhouse gas emissions in the USA. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
- Del Grosso, S.J., A.R. Mosier, W.J. Parton and D.S. Ojima. 2005. DAYCENT model analysis of past and contemporary soil N2O and net greenhouse gas flux for major crops in the USA. Soil Tillage and Research, 83:9-24.
- Halvorson, Ardell D., Arvin R. Mosier, and Curtis A. Reule. 2003. Irrigated crop management effects on productivity, soil nitrogen, and soil carbon. Proc. 2003 Fertilizer Industry Round Table, October 28-30, Winston-Salem, NC. The Fertilizer Industry Round Table, Forest Hill, Maryland. CD-ROM publication
- Halvorson, A.D., A.R. Mosier, and C.A. Reule. 2003. Nitrogen, tillage, and irrigated crop rotation effects on soil carbon sequestration. Agron. Abstr., ASA-CSSA-SSSA, Madison, WI. CD-ROM publication.
- Mosier, A.R., S.J. Del Grosso, A.D. Halvorson, W.J. Parton, G.A. Peterson, and G.P. Robertson. 2003. Measurement and modeling of soil-atmsophere N2O, CH4, and CO2 exchange for net global warming potential in agroecosystems. Agron. Abstr., ASA-CSSA-SSSA, Madison, WI. CD-ROM publication.
- Mosier, A.R. and A.D. Halvorson. 2003. Impact of tillage, crop sequence and N-fertilization on trace gas exchange in an irrigated agroecosystem in northeastern Colorado. AGU Abstract #411, Session B26, Fall meeting, Dec. 8-12, 2003, San Francisco, CA. EOS Transactions. CD-ROM publication.
- Del Grosso, S.J., W.J. Parton, A.R. Mosier, E.A. Holland, E. Pendall, D.S. Schimel & D.S. Ojima. 2005. Modeling soil CO2 emissions from ecosystems, Biogeochemistry 73:71-91.
- Liu, X.J., A.R. Mosier, A.D. Halvorson., and F.S. Zhang. 2005. Tillage and nitrogen application effects on nitrous and nitric oxide emissions from irrigated corn fields. Plant and Soil 276 (1-2): 235-249.
- Mosier, A.R., A.D. Halvorson, G.A. Peterson, G.P. Robertson, and L. Sherrod. 2005. Measurement of net global warming potential in three agroecosystems. Nutrient Cycling in Agroecosystems. 72:67-76.
- Halvorson, A.D., A.R. Mosier, C.A. Reule, and X.J. Liu. 2005. Tillage and nitrogen effects on soil carbon and greenhouse gas emissions under irrigated continuous corn. Abstract. Third USDA Symposium on Greenhouse Gases and Carbon Sequestration in Agriculture and Forestry, March 21-24, 2005, Baltimore, MD. p. 112.
- Halvorson, A.D., A.R. Mosier, C.A. Reule, and Walter C. Bausch. 2005. Nitrogen and tillage affects on irrigated continuous corn yields. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
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Progress 10/01/03 to 09/30/04
Outputs
Managing agricultural systems to optimize soil organic carbon (SOC) storage and minimize nitrous oxide (N2O) emissions can impact future concentrations of greenhouse gases, CO2 and N2O, in the atmosphere as well as the sustainability of irrigated cropping systems. Nitrogen fertilization is essential to maintaining economical crop yields, but excessive N application increases N2O emissions which can offset gains in SOC storage. Irrigated crop management systems need to be developed that will increase SOC storage and decrease N2O emissions, thus, decreasing the net global warming potential (GWP). The effects of crop rotation, tillage system, and N fertilization on the net GWP under irrigated conditions are being measured under irrigated conditions with data collected being used to verify the DAYCENT ecosystem C, N and trace gas model output for irrigated agriculture. Located on a clay loam soil in northeastern Colorado, two no-till (NT) crop rotations and a conventional
till (CT) continuous corn rotation each with three N rates were monitored for crop residue-C inputs to the soil surface, residual soil NO3-N, SOC, and total soil N (TSN) as well as soil-atmosphere exchange of CH4, CO2 and N2O gases. The gases were measured by placing vented chambers over field installed chamber anchors and quantifying the change in gas concentrations within the chambers over half hour periods, two to three times per week. Crop residue C returned to the soil surface has increased with increasing N level for each rotation. SOC levels appear to be increasing each year in the NT systems but not in the CT system. Seven tillage operations were required to prepare a seedbed in the CT system. Thus, fossil fuel requirements to produce a corn crop were substantially less with NT than with CT system. Gas flux measurements, using vented (N2O) and dynamic (NO) chambers, within plots cropped continuously to corn (Zea mays L.) under CT and NT and fertilized with 0, 134 and 224 kg N
ha-1, show that N2O and NO fluxes increased linearly with N application rate. Compared with CT, NT significantly reduced emissions of N2O in 2003 and NO in 2003 and 2004 but did not significantly affect emission of N2O in 2004. In 2003 and 2004 corn growing seasons, the increase in N2O-N emitted per kg ha-1 of fertilizer N added was 14.5 and 4.1 g ha-1 for CT, and 11.2 and 5.5 g ha-1 for NT, respectively. However, the increase in NO-N emitted per kg ha-1 of fertilizer N added was only 3.6 and 7.4 g ha-1 for CT and 1.6 and 2.0 g ha-1 for NT in 2003 and 2004, respectively. During the non-crop period (November 2003 to April 2004), much greater N2O (2.0-3.1 times) and NO (13.1-16.8 times) were emitted from CT than from NT with previous N application not showing obvious carry-over affects on gas emissions. Results reveal that NT has potential to reduce NO emission without an increase in N2O emission under continuous irrigated corn cropping compared to CT.
Impacts
Converting irrigated cropland from an intensively tilled to a no-till production system increased soil organic carbon (SOC) sequestration, but generally had little effect on carbon dioxide (CO2), nitrous oxide (N2O) or methane (CH4) emissions. N2O emissions increased with increasing N rate, but CO2 and CH4 emissions were not affected. The increase in SOC storage with NT helps offset N2O emissions from N fertilization needed to optimize crop yields and economic returns compared with the intensively tilled system, thus reducing global warming potential.
Publications
- Halvorson, Ardell D., Arvin R. Mosier, and Curtis A. Reule. 2003. Irrigated crop management effects on productivity, soil nitrogen, and soil carbon. Proc. 2003 Fertilizer Industry Round Table, October 28-30, Winston-Salem, NC. The Fertilizer Industry Round Table, Forest Hill, Maryland. CD-ROM publication
- Halvorson, A.D., A.R. Mosier, and C.A. Reule. 2003. Nitrogen, tillage, and irrigated crop rotation effects on soil carbon sequestration. Agron. Abstr., ASA-CSSA-SSSA, Madison, WI. CD-ROM publication.
- Mosier, A.R., S.J. Del Grosso, A.D. Halvorson, W.J. Parton, G.A. Peterson, and G.P. Robertson. 2003. Measurement and modeling of soil-atmsophere N2O, CH4, and CO2 exchange for net global warming potential in agroecosystems. Agron. Abstr., ASA-CSSA-SSSA, Madison, WI. CD-ROM publication.
- Mosier, A.R. and A.D. Halvorson. 2003. Impact of tillage, crop sequence and N-fertilization on trace gas exchange in an irrigated agroecosystem in northeastern Colorado. AGU Abstract #411, Session B26, Fall meeting, Dec. 8-12, 2003, San Francisco, CA. EOS Transactions. CD-ROM publication.
- Halvorson, A.D., Mosier, A.R., and Reule, C.A. 2004. Nitrogen and crop management influence irrigated crop yields and greenhouse gas emissions. In Proc. of 2004 Great Plains Soil Fertility Conference. Denver, CO, March 2-3, 2004. Alan Schlegel (ed.), Kansas State University, Manhattan and Potash and Phosphate Institute, Brookings, SD. 10:21-27.
- Mosier, A.R., A.D. Halvorson, G.A. Peterson, G.P. Robertson, and L. Sherrod. 2005. Measurement of net global warming potential in three agroecosystems. Nutrient Cycling in Agroecosystems. (In press, 6/29/04)
- Mosier, A.R., A.D. Halvorson, C.A. Reule, and X.J. Liu. 2004. Impact of tillage and N-fertilization on trace gas exchange in irrigated corn in northeastern Colorado. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
- Del Grosso, S.J., A.R. Mosier, W.J. Parton, and D.S. Ojima. 2004. DAYCENT model analysis of past and contemporary agricultural soil N2O and net greenhouse gas emissions in the USA. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
- Halvorson, A.D., A.J. Schlegel, A.R. Mosier, and C.A. Reule. 2004. Crop residue carbon and nitrogen returned to the soil in irrigated cropping systems. Agron. Abst., ASA-CSSA-SSSA, Madison, WI. CD-Rom publication.
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Progress 10/01/02 to 09/30/03
Outputs
Managing agricultural systems to optimize soil organic carbon (SOC) storage and minimize nitrous oxide (N2O) emissions can impact future concentrations of greenhouse gases, CO2 and N2O, in the atmosphere as well as the sustainability of irrigated cropping systems. Nitrogen fertilization is essential to obtain economical crop yields, but N application increases N2O emissions which can offset gains in SOC storage. Information is critically needed for developing irrigated crop management systems that will increase SOC storage and decrease N2O emissions, thus, decreasing the net global warming potential (GWP) in the future. The effects of crop rotation, tillage system, and N fertilization on the net GWP [SOC storage, methane (CH4) oxidation, N2O emissions and estimated fossil fuel use] under irrigated conditions are being measured under irrigated conditions with data collected being used to verify the DAYCENT ecosystem C, N and trace gas model output so that the model can
be used in regional net GWP studies for irrigated agriculture. Located on a clay loam soil, two crop rotations with six N rates under NT management and a CT, continuous corn rotation with four N rates were monitored for crop residue-C inputs to the soil surface, residual NO3-N in the soil profile, SOC, and total soil N (TSN) as well as soil-atmosphere exchange of CH4, CO2 and N2O gases. The gases were measured by placing vented chambers over field installed chamber anchors and quantifying the change in gas concentrations within the chambers over half hour periods, two to three times per week. Measurement of CO2, N2O, and CH4 fluxes were made in the low and high N treatments from the NT and CT continuous corn plots and from a NT corn-soybean rotation. Corn residue C returned to the soil surface increased with increasing N level for each of the continuous corn rotations, but was not influenced by N rate in the corn-soybean. SOC levels are increasing each year in the NT systems but not
in the CT system. Tillage operations in 2003 for the CT system included shredding the corn stalks after harvest, one pass with a disk to incorporate residue, moldboard plowing (about 30 cm deep), two passes with roller-mulcher to break down large clods from plowing operation, and two passes with land leveler to prepare seed bed. Thus, fossil fuel requirements to produce the 2003 corn crop were substantially less with the NT system than with the CT system. Preliminary calculations suggest that soil respiration was approximately 30% higher under CT than under NT while N2O and CH4 fluxes did not differ with tillage. Under the irrigated conditions imposed on the corn field, the soil acted as a source for CH4 rather than a sink continually over the period for which data have been processed. The N2O emissions increased with N fertilization rate while neither CO2 nor CH4 fluxes were impacted by the rate of N fertilization. Nitrogen fertilization is however essential to optimize crop yield
potential and to maintain an economically viable farming system. The increase in SOC storage with NT is helping offset N2O emissions from N fertilization needed to optimize crop yields compared with the CT system.
Impacts
Converting irrigated cropland from an intensively tilled to a no-till production system increased soil organic carbon (SOC) sequestration and reduced carbon dioxide (CO2) emissions, but had no effect on nitrous oxide (N2O) or methane (CH4) emissions. N2O emissions increased with increasing N rate, but CO2 and CH4 emissions were not affected. The increase in SOC storage with NT is helping offset N2O emissions from N fertilization needed to optimize crop yields and economic returns compared with the intensively tilled system, thus reducing global warming potential.
Publications
- Halvorson, Ardell D., Arvin R. Mosier, and Curtis A. Reule. 2003. Irrigated crop management effects on productivity, soil nitrogen, and soil carbon. Proc. 2003 Fertilizer Industry Round Table, October 28-30, Winston-Salem, NC. The Fertilizer Industry Round Table, Forest Hill, Maryland. CD-ROM publication
- Halvorson, A.D., A.R. Mosier, and C.A. Reule. 2003. Nitrogen, tillage, and irrigated crop rotation effects on soil carbon sequestration. Agron. Abstr., ASA-CSSA-SSSA, Madison, WI. CD-ROM publication.
- Mosier, A.R., S.J. Del Grosso, A.D. Halvorson, W.J. Parton, G.A. Peterson, and G.P. Robertson. 2003. Measurement and modeling of soil-atmsophere N2O, CH4, and CO2 exchange for net global warming potential in agroecosystems. Agron. Abstr., ASA-CSSA-SSSA, Madison, WI. CD-ROM publication.
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