2007 Annual Report 1a.Objectives (from AD-416) 1. Assessing carbon sequestration and trace gas emissions under conservation practices at the landscape scales in the Mid-Atlantic region as part of the GRACEnet CLP (cross-location project). 2. Develop methods to measure and characterize crop residues and soil carbon under different management systems at field to watershed scales. 3. Assessing impacts of soil redistribution on carbon dynamics by use of a biogeochemical model that includes landscape processes at field to watershed scales. 4. Modeling soil carbon sequestration and carbon fluxes at watershed to regional scales. 5. Integrate global soil moisture mapping from satellites into the land surface component of atmospheric prediction models. 1b.Approach (from AD-416) This project will quantify soil and crop residue C by spectroscopic characterization will provide cost-effective methods for monitoring or model validation. Trace gas emissions from winter cover crops will be monitored to assess overall global warming potential of prospective management practices for C sequestration. The C fluxes associated with soil erosion and subsequent C redistribution over a field or landscape will be assessed using Cesium-137 used as a tracer to estimate the magnitude and impact on redistribution patterns at field and watershed scales. Tower flux measurements will be used to validate spatial estimates of CO2 assimilation through the light use efficiency parameter. Combined crop growth/biogeochemical models use land cover, leaf area index, and soil and residue C for spatial model inputs and light use efficiency for model validation. Improved technologies and models developed for assessing soil moisture status will enhance global climate models for climate change predictions. 4.Accomplishments 1. Using Environmental Tracers to Measure Sediment Source: The Hanalei River delivers suspended sediments and organic matter to Hanalei Bay which has important implications for the sustainability of coral reefs and their many associated species in the Bay. The NRCS needs to identify sediment source areas in the watershed as a key component for consideration in the design of management strategies to reduce sediment and chemical loads to the Bay. Fallout Cs-137 was used as a tracer to identify sediment sources and as a marker to determine floodplain deposition patterns and rates within the watershed. Cs-137 concentration varied with upland soils > colluvial slope soils > floodplain deposits > stream banks > Bay sediments. Preliminary results indicate that channel banks and mass wasting are probably the most significant sources of sediments deposited on the floodplains and in the Bay. This addresses NP 204 Component I: Carbon Cycle and Carbon Storage Problem Area: Cropping System and Tillage. 2. Developing Remote Sensing Tools to Measure Crop Residues: Crop residue management is critical for minimizing soil erosion and enhancing soil carbon sequestration. Traditional methods of measuring residue cover are unsuited for characterizing the spatial variability of residue cover over many fields. Remote sensing methods typically exploit spectral differences between soils and residues for estimating crop residue cover. Soil reflectance is assumed to be a stable end-point and that changes in scene reflectance are due to crop residue cover. However, variations in reflectance associated with changes in soil composition (mineralogy and carbon content) across landscapes can mask the subtle changes in reflectance due to crop residue cover. To characterize this source of variation, reflectance spectra and soil mineralogy data for more than 600 topsoil samples from the USDA-NRCS National Soil Classification Center were examined. Soil and crop residue type significantly affected spectral residue indices that are based on visible and near infrared reflectance ratios and normalized differences. Spectral residue indices based on cellulose absorption features, present in residues but absent in soils, were generally robust. Regional surveys of crop residue cover may be feasible using advanced imaging systems. This addresses NP 204 Component I: Carbon Cycle and Carbon Storage Problem area: Measurement, validation and modeling. 3. Mapping Soil Moisture using Thermal Satellite Imagery: A methodology has been developed to estimate soil moisture using satellite imagery acquired in the thermal waveband. In comparison with standard microwave-band moisture mapping techniques, the thermal band has the advantage of having higher spatial resolution (10s of meters) and the ability to detect moisture deficits under dense vegetation cover. The algorithm was tested using thermal data collected with the Geostationary Operational Environmental Satellites (GOES) over the state of Oklahoma in comparison with ground observations from the Oklahoma Mesonet. The comparison yielded a root-mean-square error of 0.06 cm3/cm3 in average volumetric soil moisture content (1-100cm depth) over a full range in vegetation cover conditions. Pending further validation under varying landcover types and climatic conditions, these methods will facilitate soil moisture mapping at 5-10km spatial resolution across the U.S. and other countries with geostationary satellite coverage. This addresses NP 204 Component IV: Changes in Weather and the Water Cycle at Farm, Ranch and Regional Scales Problem area: Scaling of Climate Change to Field, Ranch and Regional Scales. 4. Emissions of Nitrous oxide from Biosolids Applied to Soil: The annual production of biosolids in the United States exceeds six million tons and approximately 60% of that is applied as soil amendment but little is known about nitrous oxide emissions associated with soil application. We measured the variation in nitrous oxide emissions from soil amended with 40 different biosolids with a wide range in properties. The results showed that nitrous emission rates varied substantially over this range of biosolids. These studies provide important information on factors affecting greenhouse gas emissions associated with land application of biosolids and will lead to improved management of biosolid use to reduce impacts on global climate change. This addresses NP 204 Component I: Carbon Cycle and Carbon Storage Problem area: Cropping System and Tillage. 5. Comparing Different Methods for Rapid Measurement of Soil Carbon: There is need for rapid methods for measurement of soil carbon to facilitate implementation of environmental markets which award credit to farmers for terrestrial storage of carbon. Experiments were completed at the Beltsville experimental watershed for the evaluation of on-site analysis of soils by mid-infrared spectroscopy as well as other techniques including Laser Induced Breakdown Spectroscopy (LIBS) and INS were also included. Another experiment was initiated at sites on the eastern shore of Maryland which compare mid-infrared, near-infrared, a commercial in-situ near-infrared system. These experiments will lead to improved methods to measure terrestrial soil carbon and enable carbon trading in environmental markets. This addresses NP 204 Component I: Carbon Cycle and Carbon Storage Problem area: Measurement, validation and modeling. 6. Soil Moisture Modeling for Crop Yield Predictions: Initiated the operational (near real-time) delivery of processed AMSR-E soil moisture data into the USDA’s Foreign Agricultural Service (FAS) operational global crop forecast system. The FAS international crop forecast are widely utilized to improve the competitive position of U.S. agriculture products in the world market place and ensure national food security. The AMSRE passive microwave sensor aboard the NASA AQUA satellite currently provides the best available global source of surface soil water availability. This research developed a set of processing techniques to transform AMSRE soil moisture retrievals into the format required by FAS for inclusion into their global crop monitoring system - thus ensuring the system has access to the highest quality soil moisture data. Soil moisture is a major environmental factor driving variations in crop yields. Furthermore, since many global change scenarios include rapid changes in mid-latitude growing-season soil water availability, its overall importance on agricultural productivity will likely be amplified in the future. This addresses NP 204 Component IV: Changes in Weather and the Water Cycle at Farm, Ranch and Regional Scales Problem area: Scaling of Climate Change to Field, Ranch and Regional Scales. 7. Improving Regional Carbon Models and Decision Support Tools: Regional soil carbon models and decision support tools are important for national assessments of net greenhouse gas emissions from agriculture and for optimum soil management for carbon sequestration. Long-term data sets of soil carbon changes under various soil management, crop rotations and yields were reviewed and available data across the U.S. Corn Belt were identified for model testing and validation. A 5-year database (2002-06) of MODIS TERRA imagery, surface climatic data from NOAA stations and soil profile physical characteristics was completed. The EPIC (Environmental Policy Integrated Climate) model simulations were validated at several field sites in Iowa and soil carbon simulations were completed across the entire state predicting changes in soil carbon over the next 25 years for several management scenarios. This addresses NP204 Component I: Carbon Cycle and Carbon Storage Problem area: Measurement, validation and modeling. 8. Improving Estimates of Greenhouse Gas Flux Using Remote Sensing: The amount of carbon sequestration in the soil is the difference between the photosynthetic carbon flux, respiration carbon flux and carbon exported with crop yields. Eddy flux towers measure the net carbon exchange over a small footprint on the ground, but are these measurements representative over the larger region? ARS scientists in Beltsville, MD and Ames, IA conducted a major remote sensing experiment in 2005 in the Walnut Creek Experimental Watershed. Site flux data were used to determine the efficiency of converting sunlight into biomass, allowing the use of remote sensing to estimate the net carbon exchange over a larger region. This method will lead improved estimates of soil carbon sequestration using operational polar-orbiting satellites. This addresses Component I: Carbon Cycle and Carbon Storage Problem area: Measurement, validation and modeling. 9. Cloud Land Surface Interaction Campaign (CLASIC) Land Hydrology: USDA, in cooperation with NASA, DOE, and several universities developed an experiment plan aimed at understanding the interactions between the atmosphere and the land surface called the Cloud Land Surface Interaction Campaign (CLASIC). Land-atmosphere feedback mechanisms and their resulting impacts on clouds and weather have been hypothesized. Through the CLASIC observations and modeling we hope to explain and validate these hypotheses. Teams of scientists and students will make highly accurate ground-based observations of soil moisture and evapotranspiration within two ARS research watersheds. Several aircraft with new instruments that can remotely monitor these same ground variables will be used to transfer the point information to the entire 20,000 square mile CLASIC study area. Knowledge gained from this study will lead to better prediction tools that will benefit a broad spectrum of applications in agriculture ranging from more accurate weather forecasting to improved water management decisions and crop yield estimation. This addresses NP 204 Component IV: Changes in Weather and the Water Cycle at Farm, Ranch and Regional Scales Problem area: Scaling of Climate Change to Field, Ranch and Regional Scales. 10. Developing Remote Sensing Tools to Measure Soil Carbon: Hyperspectral remote sensing of soil reflectance in the near infra-red (NIR) and mid infra-red (MIR) wavelengths has been attracting attention as a promising method for rapid and cost-effective determination of soil properties. We intensively soil-sampled five tilled agricultural fields (350 sample location) and employed four remote sensing platforms (airborne NIR; tractor-mounted NIR; in-lab NIR; in-lab MIR) to predict the results of soil organic carbon and nutrient analyses. Results will assist in the selection of effective methods for remote sensing of agricultural soil properties. Development of efficient remote sensing technologies will support the evaluation of soil carbon sequestration within a precision agriculture framework, accounting for landscape factors such as topography and spatial variability. This addresses NP 204 Component I: Carbon Cycle and Carbon Storage Problem area: Measurement, validation and modeling. 5.Significant Activities that Support Special Target Populations None 6.Technology Transfer Number of newspaper articles and other presentations for non-science audiences 19 Review Publications Reeves III, J.B., Mccarty, G.W., Follett, R.F., Kimble, J.M. 2006. The potential of spectroscopic methods for the rapid analysis of soil samples. In: Lal, L., Cerri, C.C., Bernoux, M., Etchevers, J., Cerri, E., editors. Carbon Sequestration in Soils of Latin America. New York, NY: The Haworth Press. p. 423-442. Doraiswamy, P.C., McCarty, G.W., Hunt Jr, E.R., Yost, R.S., Doumbia, M., Franzluebbers, A.J. 2006. Modeling soil carbon sequestration in agricultural lands of Mali. Agricultural Systems. doi:10.1016/j.agsy.2005.09.011. Zheng, D., Hunt, E.R., Doraiswamy, P.C., McCarty, G.W., Ryu, S. 2006. Ecology of hierarchical landscapes from theory to application. In: Chen, J., Saunders, S.C., Brosofske, K.D., Crow, T.R. Linking Ecology to Landscape Hierarchies. Hauppauge, NY: Nova Publishers. p. 125-166. Anderson, M.C., Norman, J.M., Mecikalski, J.R., Otkin, J.A., Kustas, W.P. 2007. A climatological study of evapotranspiration and moisture stress across the continental U.S. based on thermal remote sensing. II. Surface moisture climatology. Journal of Geophysical Research. 112, D11112. http://dx.doi.org/10.1029/2006JD007507. Crow, W.T., Bolten, J.D. 2007. Estimating precipitation errors using spaceborne surface soil moisture retrievals. Geophysical Research Letters. 34, L08403, doi:10.1029/2007GL029450. Hively, W.D., McCarty, G.W., Angier, J.T., Geohring, L.D. 2006. Weir design and calibration for stream monitoring in a riparian wetland. Hydrological Science and Technology. 22(1-4):71-82. Ritchie, J.C., Reeves III, J.B., Krizek, D.T., Foy, C.D. 2006. Fiber composition of eastern gamagrass forage grown on a degraded, acid soil. Field Crops Research. 97:176-181. Sadeghi, A.M., Graff, C.D., Starr, J.L., McCarty, G.W., Codling, E.E., Sefton, K.A. 2006. Spatial variability in phosphorus before and after poultry manure application in small plots. Soil Science. 171:850-857. Rizzi, R., Rudorff, B.F.T., Shimabukuro, Y.E., Doraiswamy, P.C. 2006. Assessment of MODIS LAI retrievals over soybean crop in Southern Brazil. International Journal of Remote Sensing. 27(19):4091-4100. Benedetti, M.M., Daniels, J.M., Ritchie, J.C. 2007. Predicting vertical accreation rates at an archaeological site on the Mississippi River floodplain: Effigy Mounts National Monument, Iowa. Catena. 69(2):134-149.