2005 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter? The future impacts of global change, especially those of the interactions of elevated CO2, temperature, and other environmental factors, on crop productivity, water use, and carbon sequestration are largely speculative. Strategies to maximize the benefits of global change while minimizing the detriments have not been well formulated. Providing robust recommendations to stakeholders will entail experimental characterization of such interactions under open-field conditions and improving plant growth models to better represent these interactions. The project is relevant to several components of the Global Change National Program, NP204. While the primary emphasis is on determining and assessing the impact of global change on agricultural ecosystems (Component. 3)and to develop strategies for adaptation, this research inherently involves studying all aspects of carbon cycling and storage (Component. 1)from photosynthetic carbon assimilation to sequestration in the soil, the latter of which can mitigate the rate of global change. Production of trace gases (Component 2), such as N2O, will also be addressed. In addition, the influences on surface energy balance and evapotranspiration will be assessed, thereby contributing to water cycle (Component. 4)research. In addition, this research addresses the following policy-relevant science questions in the Strategic Plan of the U.S. Climate Change Science Program (2003; http://www.climatescience.gov/Library/stratplan2003/default.htm). Question 8.2: What are the potential consequences of global change for ecological systems? Question 8.3: What are the options for sustaining and improving ecological systems and related goods and services, given projected global changes? The research has the following objectives: Objective 1. Strengthen assessments of impacts of global change on crop production systems using models that better represent interactions of elevated CO2 and temperature believed largely to be mediated through the canopy energy balance. Objective 2: Develop and evaluate approaches to include temperature effects in open-field plot research on global change. 2.1. Evaluate effectiveness and costs of different technological methods of applying manipulative temperature treatments to free-air plots at a specific location. 2.2. Appraise whether natural temperature variations due to season, elevation, and latitude can be utilized as well as technology from 2.1. One approach is to assess crop growth models with regard to their ability to simulate interactive effects of elevated CO2, temperature, and other environmental factors. The models will be validated against available data sets, including our own from prior free-air CO2 enrichment experiments. The model(s) will be run with various scenarios of global climatic change to predict the effects on crop productivity, water requirements, carbon sequestration, trace gas emissions, and greenhouse gas intensity. Geospatial tools will be used to scale impacts assessed at representative sites to regional and national levels. A more experimental approach is to evaluate methods of applying temperature treatments to free-air plots. A detailed micrometeorological model will be used to aid in the evaluation. Preliminary testing suggests that infrared heating has promise, especially if altered leaf-to-air vapor pressure gradients can be compensated by proposed precise supplemental irrigation. Another experimental approach is to appraise whether natural temperature variations due to season, elevation, and latitude can be utilized as well as manipulative technology at a single site. Growth experiments will be conducted at several elevations and planting dates together with infrared heating, and we will determine if the temperature responses observed from the heater treatments are equivalent to those observed from the elevation and seasonal differences. The main benefit will be more reliable information on how to prepare for global change. Knowing the probable impacts of global change on crop production and water use in different production regions will help guide researchers, growers, policy makers, and other stakeholders in developing strategies for coping with problems and maximizing benefits, as well as for sequestering carbon to mitigate the rate of global change. The growth models developed as part of this research should prove to be valuable tools for developing flexible strategies that meet the needs of diverse stakeholders. Moreover, they will be helpful management tools for today’s farmers, and they will be useful for risk assessments. 2.List the milestones (indicators of progress) from your Project Plan. Objective 1: Strengthening assessments of impacts through crop growth modeling. 2005: Candidate models appraised for their capability to simulate processes important to global change effects on plant growth. 2006: Model validated/improved as needed with regard to CO2 effects using FACE and other data. 2007: Model validated/improved as needed with regard to temperature and CO2 effects. See 2.2 activity. 2008: Large area assessment conducted for wheat over regions, such as U.S. 2009: Assessment for other crops such as sorghum or soybean conducted. Objective 2.1: Approaches to manipulate temperature at a site. 2005: Heating approaches assessed, especially infrared heating. 2006-2009: If successful, collaborate and provide advice about heaters to other projects, such as SoyFACE, as appropriate. Objective 2.2: Appraise natural temperature variations due to elevation, season, latitude. 2006-2007: Elevation, planting date experiment conducted. Heaters included if 2.1 achieved. 2008: Temperature functions inferred from across-site data compared to those derived from at-site manipulations. 4a.What was the single most significant accomplishment this past year? In order to study the likely effects of global warming on future ecosystems, including agricultural fields, a method for applying a heating treatment to open-field plant canopies is needed that will warm vegetation as expected by the future climate. One method which shows promise is infrared heating, but a theory of operation was lacking for predicting the performance of infrared heaters. Therefore, an ARS scientist from Phoenix, AZ, derived a theoretical equation to predict the thermal radiation required to warm a plant canopy expressed as the amount of power required to heat a unit land area by one degree. It proved to have good accuracy, as was determined by comparing the theoretical performance against actual data obtained from an experimental infrared heating system. Use of the theory enables electrical power costs of conducting an outdoor warming experiment to be estimated, as well as enabling an evaluation of heater characteristics, e.g., improving the thermal emittance of the heating element could reduce seasonal electrical costs from $100,000 to $30,000. 4b.List other significant accomplishments, if any. The increasing atmospheric CO2 concentration is likely to cause partial stomatal closure in the leaves of plants growing in the future, and such partial closure would reduce water loss from individual leaves, but actual reductions in water requirements of field-grown crops are uncertain. Therefore an ARS scientist from Phoenix, AZ, in cooperation with a scientist from the Illinois State Water Survey, Urbana, IL, assembled data from several experiments that have been conducted using free-air CO2 enrichment (FACE) on crops in open fields in which measurements related to water and energy exchange were made. They showed that canopy temperatures likely will increase about 0.5'C (0.9'F) and that plant water requirements will be reduced from zero to 20%, with crops such as cotton with a large growth response to elevated CO2 having little change in water use in contrast to a crop like sorghum with a small growth response having a large percentage reduction in water use. The reductions in water use would lead to increases in soil water content and improvements in the internal water status of plants, thereby increasing growth under water-limited conditions. Temperature responses of crop growth simulation models are seldom tested in a structured, reproducible manner that facilitates cross-model comparisons. The result is that it is difficult to assess how well one model performs relative to others. A procedure for standardized assessments was in developed in 2004 and this year was applied to models for wheat, soybean, peanut, cotton, rice and tomato. The results emphasize the sensitivity of grain yield to integrated effects of temperature on phenology, net growth and partitioning. Application of the procedure should lead to substantial improvements in the reliability of modeled crop responses to elevated temperatures. Physiological relations quantified in crop growth simulation models have evolved very slowly, limiting the accuracy of modeled responses to factors such as temperature and CO2. Progress in plant genomics and related fields offer promise for greatly strengthening models, especially in description of cultivar differences. A review of the genetics of traits in wheat that affect crop growth and development was undertaken to develop a strategy for improving the representation of cultivar differences in wheat models. This work identified several opportunities for incorporating genetic information in wheat models, which should lead to improved predictions of wheat responses to global change factors. Crop growth simulation model testing and application requires access to field data describing realistic production situations. To facilitate data interchange among agronomists, modelers and other stakeholders, a set of data standards are being developed for describing field experiments in a format that can be easily used with models. A master list of variables and descriptors was developed in collaboration with ICASA. Other members of ICASA are developing software tools that will allow the standards to be used in different models. Adoption of the standards should facilitate model development and testing as well as application in studies of crop response to global change factors. 4c.List any significant activities that support special target populations. None. 4d.Progress report. None. 5.Describe the major accomplishments over the life of the project, including their predicted or actual impact. This is the first year of this new CRIS that emphasizes the development of crop growth models capable of simulating the interactive effects of increasing temperature and CO2 and other environmental factors on crop growth, as well as development of the means to properly derive the temperature functions needed for such models from outdoor-grown crops. This is a new direction compared to the previous CRIS, “Agricultural Productivity and Water Use: Effects of Global Change” (5344-11000-007-00D), which had more emphasis on elevated CO2 alone. Under that CRIS, a huge body of experimental work was accomplished, as described in its 2004 Annual Report. 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? We have continued to answer questions in support of data sets on the response of wheat to elevated atmospheric CO2 at ample and limiting supplies of water and nitrogen that have been furnished to plant growth modelers who are members of the Wheat Network that was created under the auspices of the IGBP GCTE (International Geosphere Biosphere Programme, Global Change Terrestrial Ecosystems) Focus 3: Agriculture; A3.1, Experiments on Key Crops. The data are being used to validate plant growth models, which in turn are being used to assess the likely impact of global change on wheat production in many parts of the world. Reports and packets of publications have been furnished to the Department of Energy. Besides the wheat data, we have also made our sorghum data obtained under elevated CO2 at ample and limited water supplies available to sorghum growth modelers. Much of the transfer was accomplished at a Sorghum Modeling Workshop on 22 April 2005 in conjunction with the Annual Biological Systems Simulation Workshop, which we hosted. Bruce Kimball advised the Australian Greenhouse Office of the Australian Government about utilizing free-air CO2 enrichment (FACE) technology for conducting a major experiment to examine the effects of elevated CO2 on wheat under extreme drought conditions. He participated in a planning workshop and made presentations on “Response of Plants to Elevated CO2,” “Building Resource Hungry Science: Meeting the Challenges,” and “Free-Air CO2 Enrichment Project: Methodology and Operation as Multi-User, Multi-disciplinary Facility” 3-6 May 2005, Canberra, ACT, Australia. Jeff White was named co-chair of ICASA, which seeks to promote more efficient use of models and related tools in agricultural research. His work through ICASA emphasizes development of standards for efficient data interchange among researchers. 7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). Bruce Kimball gave an invited presentation on "Long-term effects of elevated CO2 on sour orange trees" to about 50 scientists at the International Symposium on Plant Responses to Air Pollution and Global Changes, 19-22 October 2004, Tsukuba, Japan. Bruce Kimball gave a keynote address on "Global Environmental Change: Implications for Agricultural Productivity" to about 40 scientists at the International Symposium Regarding Global Climate Change and Mitigation Techniques for Agrometeorological Disasters on 26-27 October 2004 in Taichung, Taiwan. An invited talk to about 70 foresters from the Southwest on "Ecological Responses: CO2 Fertilization" was given by Bruce Kimball at a Workshop on Climate Change and Ecosystem Impacts in Southwest Forests and Woodlands, Sedona, Arizona, 8-9 February 2005. Jeff White gave an invited presentation paper on "Sensitivity Analysis and Uncertainty Analysis in Gene-Based Modeling" for the ASA Division A-3 special session "Sensitivity Analysis, Uncertainty Analysis, and Parameter Estimation for Agronomic Models" at the 2004 ASA-CSSA-SSSA meetings in Seattle, Washington, 31 Oct - 4 Nov 2004. Jeff White gave an invited presentation on "Synthesizing CO2 responses of rangelands/pasturelands: a comparison to croplands" to about 50 scientists at the Society for Range Management meetings in Fort Worth, Texas, February 8, 2005. Review Publications Edmeades, G.O., Mcmaster, G.S., White, J.W., Campos, H. 2004. Genomics and the physiologist: bridging the gap between genes & crop response. Field Crops Research. Oct. 2004. Vol. 90, pp. 5-18. Grant, R.F., Kimball, B.A., Wall, G.W., Triggs, J.M., Brooks, T.J., Pinter Jr, P.J., Conley, M.M., Ottman, M.J., Lamorte, R.L., Leavitt, S.W., Thompson, T.L., Matthias, A.D. 2004. Modeling elevated carbon dioxide effects on water relations, water use, and growth of irrigated sorghum. Agronomy Journal 96:1693-1705. Kimball, B.A. 2003. Response of plants to elevated atmospheric co2. Indian Journal of Plant Physiology (Special Issue), pp. 18-24. White, J.W., Mcmaster, G.S., Edmeades, G. 2004. Genomics and crop response to global change: what have we learned?. Field Crops Research. 90:165-169. White, J.W., Montes-R, C. 2005. Variation in parameters related to leaf thickness in common bean (phaseolus vulgaris l.). Field Crops Research. 91:7-21. Cheng, L., Leavitt, S.W., Kimball, B.A., Pinter Jr, P.J., Ottman, M.J., Matthias, A., Wall, G.W., Brooks, T., Williams, D.G., Thompson, T.L. 2004. Dynamics of labile and recalcitrant soil carbon pools in a sorghum free-air co2 enrichment (face) agroecosystem. Agronomy Abstracts. B13C-0242. Hoogenboom, G., Jones, J.W., Wilkens, P.W., Porter, C.H., Batchelor, W.D., Hunt, L.A., Boote, K.J., Singh, U., Uryaswv, O., Bowen, W.T., Gijsman, A., Du Toit, A., White, J.W., Tsuji, G.Y. 2004. Decision support systems for agrotechnology transfer version 4.0. Computer Model: Decision Support System. CD-ROM. Cheng, L., Martens, D.A., Leavitt, S.W., Matthias, A.D., Williams, D.G., Ottman, M.J., Kimball, B.A., Wall, G.W., Pinter Jr, P.J. 2003. Free air-co2 enrichment (face)of c4-sorghum: biochemical composition and decomposition of sorghum tissues grown under elevated co2. {abstract}. Agronomy Abstracts CD-ROM S03-cheng358353-poster. Kimball, B.A., Idso, S.B. 2005. Long-term effects of elevated CO2 on sour orange trees. In Abstracts of 6th International Symposium on Plant Responses to Air Pollution and Global Changes from Molecular Biology to Plant Production and Ecosystem. Yatabe Printing Co., Ltd, Tsukuba, Japan. p 80. Kimball, B.A., Zhu, J., Lei, C., Kobayashi, K., Bindi, M. 2002. Responses of agricultural crops to free-air co2 enrichment. Chinese Journal of Applied Ecology. 13(10):1323-1338 Leavitt, S.W., Idso, S.B., Kimball, B.A., Burns, J.M., Sinha, A., Stott, L. 2003. The effect of long-term atmospheric co2 enrichment on the intrinsic water-use efficiency of sour orange trees. Chemosphere. 50:217-222. Sommer, R., White, J.W. 2003. The need for improvement of crop-soil simulation models for their application in conservation agriculture. In C. Wollny, A. Deininger, N. Bhandari, B. Maass, W. Manig, U. Muuss, F. Brodbeck, I. Howe (eds.) Deutscher Tropentag 2003, International Research on Food Security, Natural Resource Management and Rural Development, Technological and Institutional Innovations for Sustainable Rural Development Book of Abstracts, Georg-August-Universitat Gottingen, p. 368 Sommer, R., Batchelor, W.D., White, J.W., Jones, J.W., Gijsman, A.J., Porter, C.H. 2004. Modeling conservation agriculture. In K.J. Peters, D. Kirschke, W. Manig, A. Burkert, R. Schultze-Kraft, L. Bharati, C. Bonte-Friedheim, A. Deininger, N. Bhandari, H. Weitkamp (eds.) Deutscher Tropentag 2004, International Research on Food Security, Natural Resource Management and Rural Development, Rural Poverty Reduction through Research for Development and Transformation Book of Abstracts, Humboldt-Universitat zu Berlin. p. 226. Adamsen, F.J., Wechsung, G., Wechsung, F., Wall, G.W., Kimball, B.A., Pinter Jr, P.J., Lamorte, R.L., Garcia, R.L., Hunsaker, D.J., Leavitt, S.W. Temporal changes in soil and biomass niotrogen for irrigated wheat grown under free-air carbon dioxide enrichment (face). Agronomy Journal. 97:160-168