Research Accomplishment Reports 2011

Characterizing Mass and Energy Transport at Different Vadose Zone Scales (from W1188)

O. O. Wendroth
Department of Plant and Soil Sciences

 

Non-Technical Summary

This project seeks to fill these gaps by developing new technologies for measuring transport, transfer, rate and state variables using comprehensive experimental designs that will yield appropriate scaling approaches. We will develop new measurement tools and process statistical structures for both measurements and processes essential for investigating soil ecosystem processes. We will improve conceptual and numerical modeling approaches that couple interdependent processes and improve our ability to transfer measurement and model information between scales. We will use our skills as soil and environmental physicists to advise and participate in national and international multidisciplinary projects to impart the importance of soil resources and the knowledge we have gained through decades of studying this critical zone.

And, we will achieve this by participating in activities, like establishing national research site observatories and measuring the spatial distribution of soil moisture across our Nation. The collaborations created and fostered through the multistate research program have spanned generations of soil physicists and hydrologists, and it is the collective opinion of the participants that multi-institutional and multi-PI collaborations have been significantly enhanced because of the multistate program. Indeed maintaining the focus of such a large group would not be possible without this multistate program. Using these collaborations, significant benefits have been realized through understanding soil physics principles and applying them to environmental sustainability of soil resources, protecting ground and surface waters, improving agricultural production, only to name a few areas. This group has maintained a flexible organization of researchers and field sites, rather than on focused, yet restrictive, approaches like common field sites or identical experimental approaches at different locations. Members tend to form and re-form around new multi-investigator programs, while addressing critical questions. This flexible and synergistic approach has been extremely productive and it encourages a rich pollination of ideas and solutions to complex problems.

The multistate committee structure is a convenient and efficient platform for establishing national research collaborations, validating approaches and techniques, pooling data, creating rigorous peer reviews, accessing unique equipment and developing the next generation of highly-educated soil scientists, environmentalists, and engineers.

This proposal seeks to maintain the ties between this extremely productive and creative group that without the W1188 committee and its long line of predecessors would not be as focused on national needs research. The proposal also highlights our efforts to improve environmental monitoring, implement basic soil physics research, reach out to a broader scientific community, and educate and communicate to stakeholders and colleagues within and outside our traditional discipline.

2011 Project Description

Events a) Two invited keynote presentations at international conferences: - Wendroth, O. 2011. Spatio-temporal soil water and related processes. Invited Keynote Lecture. Brazilian Soil Physics Meeting, September 12 -16, 2011, Department of Biosystems Engineering, Luiz de Queiroz College of Agriculture, University of Sao Paulo. ESALQ - USP, Piracicaba - SP, Brazil - Wendroth, O., G.Schwab, and L. Murdock. "How close is close enough" Oral plenary session presentation, 8th European Conference on Precision Agriculture, Prague, Czech Republic, July 10-13, 2011. b) Seven contributions at national and international conferences: - Rienzi, E.2, J. Fox, O. Wendroth, and J.H. Grove. Temporal Sediment Particle Size Distribution and Organic Carbon Release with Low and High Kinetic Energy Wetting In Interrill Erosion. Poster, Annual Meeting, ASA-CSSA-SSSA, Oct. 16-19, 2011, San Antonio, Texas. - Ritchey, E.L., J.H. Grove, R.C. Pearce, and O. Wendroth. Spatial analysis as an alternative strategy for interpreting penetrometer resistance data. Oral presentation, Annual Meeting, ASA-CSSA-SSSA, Oct. 16-19, 2011, San Antonio, Texas. - Kreba, S.2, O. Wendroth, and R. McCulley. 2011. Temporal stability of soil water storage, carbon dioxide, and nitrous oxide flux. Poster, Annual Meeting, ASA-CSSA-SSSA, Oct. 16-19, 2011, San Antonio, Texas. - Kreba, S.2, O. Wendroth, and M. Coyne. 2011. Land use impact on soil structure. Poster, Annual Meeting, ASA-CSSA-SSSA, Oct. 16-19, 2011, San Antonio, Texas. - Yang, Y.2, and O. Wendroth. 2011. Spatial variability of wet-range soil hydraulic conductivity as affected by land use. Oral presentation, Annual Meeting, ASA-CSSA-SSSA, Oct. 16-19, 2011, San Antonio, Texas. - Wendroth, O., C.J. Matocha, and L. Murdock. 2011. Additive State-Space Model for Decomposing Variation at Different Scales: Opportunities for Experiments in Variable Landscapes. Oral presentation, Annual Meeting, ASA-CSSA-SSSA, Oct. 16-19, 2011, San Antonio, Texas. - Andreas Schwen2 and Ole Wendroth. 2011. Spatial variability of macropore structures in soils under different land use. Oral presentation, Annual Meeting German Soil Science Society, Sept. 3.-9., Berlin, Germany. c) One Workshop: - Guest lecturer: Workshop on Spatial and Temporal Statistics. Dept. of Water Resources, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences. July 14-15, 2011. d) One field day - Wheat Field-Day, Princeton Kentucky, 2011, "How close is close enough" Ole Wendroth, Lloyd Murdock, Greg Schwab, R. Jason Walton. e) One Demonstration: - "The role of soils in our life" Lafayette High School, Lexington, KY, taught 2 units on Soil and Water to approximately 180 students of the Earth Science Class, May 9 and 10, 2011. 3. Services Outside Examiner for the University of the West Indies, Trinidad Reviewer (and associate editor) of 48 manuscripts throughout 2011.

2011 Impact

Short-term outcomes

-Soil spatial variability is not an obstacle but an opportunity in field-scale transient solute transport experiments.

-Additive state-space models are a promising approach to separate large-scale soil spatial variation from small-scale variation imposed by rainfall treatment in field-scale solute transport experiments.

-With increasing rainfall intensity, the solute leaching increases for the same amount of rainfall. The larger the time between solute application and subsequent rainfall, the smaller the probability of deep leaching and ground water contamination.

-Additive state-space models through their ability to separate large- from small-scale variation support appropriate nitrogen management while the assumption of one unique Yield-N-response function becomes unnecessary.

-In farmers' fields, with current technology, nitrogen application rate in wheat can be managed at a scale of 4 by 5 m2 or larger based on crop sensors and derived vegetative indices, e.g., NDVI. It is not reasonable yet to manage at a smaller scale.

Activities

- A field-scale solute leaching experiment was conducted to improve understanding of the impact of land use, rainfall amount, intensity and application time delay on the leaching of bromide.

- A remote-sensing based experiment was conducted in a farmer's field in Western-KY to test the improvement of N-fertilization through the use of the GreenSeeker and derived NDVI of winter wheat.

- An additive state-space statistical model was adapted for the analysis of agricultural experiments. Treatments can efficiently applied non-randomly but varying periodically at different scales so that underlying soil heterogeneity effects can be compensated in the analysis.

- A graduate level course in soil physics (with lab) was taught. Two graduate students were advised, served on committees of six graduate students during this year. A visiting graduate student from Austria was mentored, external reviewer of one PhD thesis.

2011 Publications

Wendroth, O., V. Vasquez, and C.J. Matocha. 2011. Field experimental approach to bromide leaching as affected by scale-specific rainfall characteristics. Water Resour. Res. 47, W00L03, doi: 10.1029/2011WR010650.

Wendroth, O., L. Murdock, and G. Schwab. 2011. How close is close enough In: Stafford, J.V. (Ed.). Precision Agriculture 2011. Proc. 8th Europ. Conf. Prec. Agric., Prague, Czech Republic, p. 17-28.