Welcome to the Crop and Soil Sciences Seminar Series. Following is a list of the seminars scheduled for the Fall of 2004 and Spring 2005. Unless otherwise noted, all seminars are on Thursday, from 12:20 PM to 1:10 PM in 135 Emerson Hall.

Crop and Soil Sciences

SPRING 2005

1/27/05 - Integrative Technologies in Support of GIS-Based Post-Disaster Response (Art Lembo, Senior Research Associate/Senior Lecturer, Crop and Soil Sciences, Cornell University). Abstract: Art Lembo will present a seminar on the use of integrative technologies for responding to disasters. The talk is an overview of Art's current NSF work integrating the fields of Internet Map Server technology and natural disaster response. In addition to an overview of the latest geospatial technologies in this field, Art will show how Cornell is using these technologies in response to the Indian Ocean tsunami disaster and communicate many of the lessons learned within the last month.

2/3/05 - Carbon and Hydrology in Forested Headwater Catchments in the Southern Amazon (Mark JohnsonPhD Candidate, Crop and Soil Sciences, Cornell University. Abstract: Understanding the fluvial transport of terrestrially-fixed carbon and its subsequent outgassing to the atmosphere is central to efforts to resolve the carbon balance for the Amazon forest. Soil and topographic controls on hydrologic flow paths are tightly coupled with carbon cycling, with spatial variability in soil physical properties affecting the rainfall-runoff responses of the watersheds studied. During storm events, surficial flow paths deliver particulate and dissolved organic carbon (DOC) to streams, which is subject to re-mineralization further downstream. On an annual basis, DOC represents 59% of total organic C exports for the watersheds studied. During the dry season, DOC exports from headwater streams are driven by in-stream decomposition of terrestrial litterfall, while during the rainy season, high DOC concentrations in overland flow and throughfall drive catchment DOC exports. The deeper flow paths following infiltration allow for equilibration of pore water with high CO2 levels in the soil atmosphere, resulting in rapid outgassing in headwater streams from groundwater discharge that is highly enriched in CO2 (30,000 ppm). Results indicate that the outgassing of CO2 within headwater streams is the predominant fluvial C export from headwater catchments.

2/10/05 - Support Vector Machines for Remotely Sensed Image Classification (Pramod Varshney, Professor, Engineering and Computer Science, Syracuse University). Abstract: Land cover information is a key to many diverse applications such as natural resource management, planning, and monitoring programs. Remotely sensed images are attractive sources for extracting land cover information, where an image classification algorithm is employed to retrieve land cover information. Recently, Support Vector Machines (SVM) have been proposed as an approach to produce land cover classification. In this presentation, we shall elaborate on the construction of a classifier based on SVM algorithms for binary classification problems and its extension to multi-class classification. In addition, we shall present experimental results on image classification based on an SVM algorithm to create a crisp classification map and a soft classification map of remotely sensed data.

2/17/05 - Whither goes Soil Science in North America? Survey Results and Analysis (Philippe Baveye, Professor, Crop and Soil Sciences, Cornell University). Abstract: This talk is based on a manuscript in preparation, written in collaboration with Astrid Jacobson, John Tandarich and Ray Bryant. It will report on several surveys of soil science graduate education in the US and Canada that have been conducted over the last 12 years. These surveys reveal a marked decrease, by about 50%, of the number of graduate students in the field over the last 12 years. Many departments that used to have "soil science" in their name have changed it, so that soil science is progressively becoming less and less visible as a discipline. Like 12 years ago, students continue to be strongly interested in environmentally-related aspects of soil science, in spite of the fact that the main scholarly society (the Soil Science Society of America) purporting to defend/promote the interests of the discipline in the US still views agriculture as its central focus. All of these trends raise questions about the sustainability of soil science as a scientific discipline. Several possible avenues to avoid an implosion are briefly discussed.

2/24/05 - Arsenic Contamination of Rice in Bangladesh: Risk Assessment and Management Strategies (Steve DeGloria and Julie Lauren, Crop and Soil Sciences, Cornell University Abstract: This presentation will focus on: (1) a spatial assessment of the risk of arsenic contamination of rice based on the use of arsenic contaminated groundwater for irrigation in Bangladesh, and (2) the development of management strategies to reduce arsenic uptake by rice plants. We mapped the potential risk of arsenic contamination of irrigated winter rice based on the average arsenic concentrations in groundwater and the proportion of winter rice irrigated with groundwater at a national scale. Risk assessment and mapping indicate that over 76% of total irrigated winter rice is grown where mean groundwater arsenic concentrations are below 50 ug/L. Management strategies for areas where arsenic contamination risk is high include use of alternative water sources for irrigation, crop substitution and more aerobic management practices.

3/3/05 - Development of a Robust Indicator of Soil Organic Matter Status (John Gaunt, Director GY Associates, Adjunct Professor, Cornell University). Abstract: We will present a project undertaken in the UK that sought to establish a robust indicator of soil organic matter status. Through interviews with land managers we sought to establish the benefits and costs attributed to soil organic matter management. This work confirmed the benefit in many situations of managing soil organic matter. We then present or findings on the development of an indicator framework for soil organic matter status.

3/10/05 - Soils at Sea: The Potential of Sea-farming to Alleviate Food Shortages (Ricardo Radulovich, Professor, University of Costa Rica)

3/17/05 - Impact of Forest Degradation on Hydrologic Processes in Southern India (Vishal Mehta, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Landuse/landcover is tightly coupled to hydrology - hence changes in landuse impact water balance. In southern India, there are no comprehensive studies on how historic and ongoing forest cover loss or degradation has impacted hydrological processes. My research focus is to quantify the complete water balance in degraded and undisturbed forest areas in a region in southern India that is a biodiversity hotspot, impacted by intensive land use practices. Literature review, problem statement, proposed field research methods, and expected outcomes will be presented. Also included will be an overview of collaborative research arrangements with respect to a project of broader scope within which my research is situated, initial secondary data analysis, and ideas for extending local, small scale results to larger spatial scales.
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3/17/05 - Organic Matter Stabilization in Biogenic Nanostructures of Soil Micro-aggregates (James Kinyangi, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Physicochemical binding in organo-mineral complexes of soil micro-aggregates contributes to carbon stabilization in soils. We combined nano-scale sample processing with synchrotron based scanning transmission x-ray microscopy (STXM) and near edge x-ray absorption fine structure spectroscopy (NEXAFS) to investigate the protection of carbon within interior and exterior pore regions of intact soil micro-aggregate sections. We observed a highly patchy, near random nano-scale distribution of C that was stabilized between pore spaces and bound to the mineral domain. Organo-mineral formations of nano-aggregates were visible proximal to mineral and organic matter assemblages. Our results indicate that combining STMX with C NEXAFS affords a powerful, non-destructive approach to identify and fingerprint complex structural characteristics of organic macromolecules that stabilize C in soil.

3/24/05 - SPRING BREAK

3/31/05 - Characterization and spatial modeling of land degradation for agroecosystem management in Western Kenya (Tom Owiyo, PhD Candidate, Crop and Soil Sciences, Cornell University). Abstract: This project investigates the feasibility of spatially modeling land degradation at landscape scale in western Kenya. The first step involved acquiring and modeling visible-near infrared (NIR) spectroscopy to estimate several soil properties using two statistical approaches: multivariate adaptive regression splines (MARS) and partial least squares (PLS) and their results are compared. Soil organic carbon was used as an indicator of soil degradation and different regression approaches were applied to characterize its distribution in the region using landscape variables. Finally, an attempt is made to use ancillary data from digital elevation model and from satellite imagery (Advanced Spaceborne Thermal Emission and Reflectance Radiometer) to predict soil organic carbon levels in the landscape.

4/7/05 - Assessing Potential Biological Indicators of Soil Quality in Conjunction with Physical Indicators: Microbial Analyses from Intact Cores and Glomalin in Soil Aggregates (Daniel Clune, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: There is increasing interest in indicators of soil biological, physical and chemical quality for use in guiding soil management practices. Robust biological indicators have been particularly elusive. We are developing a protocol that enables successive, yet integrated, measurement of soil biological and physical properties from intact soil cores. Saturated hydraulic conductivity of intact cores, followed by measures of macro- and meso-porosity bring the cores to a common moisture tension at which point soil respiration is measured while the core physical structure remains intact. Cores are subsequently sub-sampled for: microbial biomass, N mineralization potential, microbial community structure, microporosity and bulk density. In this way, an integrated set of biological and physical soil measures is obtained. Cores taken from long-term field trials at Willsboro and Chazy, NY are being used to evaluate the sensitivity and utility of each measured 'indicator'. We are also investigating the relationship between water-stable aggregation and content of glomalin, a glycoprotein produced by the arbuscular mycorrhizal fungi. Glomalin purportedly plays a role in water-stable aggregation and may prove to be a useful integrative indicator of soil biological and physical quality..
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4/7/05 - Rapid Assessment of Physical Indicators of Soil Health for Public Service in New York State (Bianca Moebius, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Farmers and environmentalists around the world are becoming increasingly interested in evaluating soil health. We have developed a soil physical health testing laboratory that features rapid, scientifically meaningful, and agronomically useful tests that can be performed inexpensively. Tests for aggregate size distribution and stability, saturated hydraulic conductivity, macro-, meso- and microporosity, penetration resistance, bulk density, available water capacity, and van Genuchten parameters will be available. Controlled long-term soil management experiments at Willsboro, Chazy and Aurora, NY were used to evaluate the utility of these tests and their ability to detect treatment effects. Available data from grower members of the Cornell Soil Health Project and other research sites are used in addition to data from controlled sites to develop standard interpretations of the laboratory results, and evaluate correlations with chemical and biological soil health indicators.

4/14/05 - Glyphosate sorption and complexation reactions in Northeastern US soils (Katherine Barrett, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Glyphosate, the most widely applied herbicide in North America, is an anionic molecule with metal-complexing characteristics that promote strong sorption to soil mineral surfaces and the formation of chelates with metal cations. This research investigated the reaction of glyphosate with soil minerals and organic matter to determine the potential for metal chelation to mobilize metals such as Cu. In addition, experiments were performed to determine whether glyphosate complexation with surface Mn, using birnessite (a Mn oxide present in local soils), could lead to oxidative decomposition of the herbicide. Although high rates of glyphosate application solubilized several metals as well as anions (including phosphate and arsenate) in the soils tested, the strong tendency of glyphosate to adsorb on both mineral and organic surfaces probably limits metal mobilization in most soils. Further, glyphosate decomposed abiotically via phosphonate C-P bond cleavage relatively rapidly on laboratory-prepared Mn oxide, with the release of phosphate into solution. This oxidative degradation may be of environmental significance in some situations, but in surface soils its importance is likely to be exceeded by more rapid processes of microbial degradation.
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4/14/05 - Management Factors that Influence Nitrous Oxide Losses: Field Studies and Modeling Ivy Tan, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: Glyphosate, the most widely applied herbicide in North America, is an anionic molecule with metal-complexing characteristics that promote strong sorption to soil mineral surfaces and the formation of chelates with metal cations. This research investigated the reaction of glyphosate with soil minerals and organic matter to determine the potential for metal chelation to mobilize metals such as Cu. In addition, experiments were performed to determine whether glyphosate complexation with surface Mn, using birnessite (a Mn oxide present in local soils), could lead to oxidative decomposition of the herbicide. Although high rates of glyphosate application solubilized several metals as well as anions (including phosphate and arsenate) in the soils tested, the strong tendency of glyphosate to adsorb on both mineral and organic surfaces probably limits metal mobilization in most soils. Further, glyphosate decomposed abiotically via phosphonate C-P bond cleavage relatively rapidly on laboratory-prepared Mn oxide, with the release of phosphate into solution. This oxidative degradation may be of environmental significance in some situations, but in surface soils its importance is likely to be exceeded by more rapid processes of microbial degradation.

4/21/05 - Amazonian Forest Structure in an Ecotone and Relationships to Soil and Landscape Characteristics (Stefan Jirka, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Elucidating factors that contribute to spatial dynamics in forest composition and structure can help inform forest management. We studied the distribution of vegetation with respect to soil and landscape characteristics in a logging concession in the southwestern Amazon Basin. Large differences in stem density, basal area, life form and taxonomic composition across the landscape characterize distinct forest types ranging from scrub savanna to palm-dominated to upland hardwood forest. Initial results indicate that soil water status strongly influences the patchy nature of these forest types in our study area. Ordination analyses and geostatistical approaches are being applied to identify the spatial structure of forest vegetation and soil properties.
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4/21/05 - Unlocking Microbial Community Diversity in Brazilian Terra Preta Soils and Adjacent Oxisols (Brendan O'Neill, MSc Student, Crop and Soil Sciences, Cornell University). Abstract: Anthropogenic Dark Earths, or Terra Preta do Indio (TP) soils, originate from pre-Colombian, settled agriculture that occurred throughout the Amazon Basin (500-2500 BP), ranging in extent from small plots to hundreds of hectares. TP soils contain high levels of charcoal or black carbon (BC) and, while their remarkable chemical fertility is well documented, the microbiology in TP has barely been examined. In coordination with the Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) and the Amazonas National Research Institute (INPA) and the Center for Nuclear Energy and Agriculture (CENA), we analyzed soil cores from three sites in the Brazilian Amazon with TP and adjacent oxisols using traditional culturing techniques and molecular approaches. Counts of total culturable bacteria were significantly higher in TP as compared to adjacent oxisols. Plating onto selective media revealed distinct differences in culturable organisms between the oxisols and TP with high amounts of BC. Methods for DNA extraction were optimized to increase nucleic acid yield from soils containing BC. The 16S rRNA genes of eubacteria and archaea were successfully amplified from these soil DNA extracts. Denaturing gradient gel electrophoresis (DGGE) community profiles and subsequent cloning and sequencing of selected DGGE bands and bacterial isolates from the soils reveal highly differing bacterial communities in the TP soils compared to their associated oxisols. Differential microscopic staining techniques are being used to evaluate surface microbial communities associated with BC. Along with the unique biochemistry of BC, these results show an abundant microbial community associated with BC which also makes TP distinct.

4/28/05 - Strategies for Improving Rice Yields on Salt-affected Soils of the Chokwé Irrigation System, Mozambique (Zelia Menete, PhD Candidate, Crop and Soil Sciences, Cornell University). Abstract: Rice feeds more than half the people in the world, and an increase in rice yield and production is required to satisfy increasing food demand. The system of rice intensification (SRI) has been proposed as an integrated and agro-ecologically sound approach to improving rice yields, especially for resource-poor farmers. Trials were conducted in a semi-arid irrigated area with salt-affected soils to test different strategies for improving rice yields were tested. Intermittent irrigation conditions (SRI) caused delay in maturity and decreased crop yields (41 %), plant height, tillers bearing panicles, grains per panicle, filled grains and grain weight while water used decreased (70 %) compared to conventional flooding. Compost application increased rice yield (12 %) moderately. Tiller-bearing panicles increased at lower plant density (SRI) but overall yield decreased (11 %). Very young seedlings (SRI) had a very positive effect on yields. Yields decreased significantly with increasing seedling age with 9.3, 8.6 and 7.8 Mg ha-1 for 10-, 20- and 30-days old seedlings, respectively. SRI-related practices showed some potential for improving rice yields but the various component practices are not universally positive on salt-affected soils.

5/5/05 - Evaluation of the Amino Sugar N Test for Predicting Corn (Zea mays L.) Yield Response to Sidedress N (Jonathan Klapwyk, MS Candidate, Crop and Soil Sciences, Cornell University). Abstract: The presidedress nitrate test (PSNT) is currently the best tool available for New York (NY) producers to determine if corn (Zea mays L.) will benefit from sidedress N. The PSNT requires 0-30 cm samples which can be difficult on stony NY soils and samples need to be taken in late-spring, an inopportune time for dairy farmers. The Illinois soil N test (ISNT) is a simple test that estimates exchangeable NH4-N and amino sugar-N and shows promise as a tool for identifying sites that are nonresponsive to sidedress N fertilization in Illinois. Field studies were conducted to (1) study the effects of manure amendments, depth of sampling, and timing of sampling on the ISNT, and (2) to determine the accuracy of the ISNT in predicting sites that nonresponsive to N in NY. Preliminary results show that increases in ISNT levels over time were consistent with estimated N credits for previously applied manure amendments and that ISNT results were lower in 0-30 than 0-20 cm depth samples. Preliminary data analyses from on-farm and research trials suggest that the ISNT is able to predict nonresponsive sites in NY. Trial results will be presented.
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5/5/05 - Growth, Reproduction and Competitive Ability of the Invasive Vine, Pale Swallow-wort (Vincetoxicum rossicum) in Northern NY State (Larissa Smith, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Ecosystem degradation due to increasing invasion by aggressive non-native plants ranks as one of the greatest threats to biodiversity. During the last 20 years, the invasive alien vine, pale swallow-wort (Vincetoxicum rossicum) [Asclepiadaceae] has become a major problem in the Great Lakes Basin of the Northeastern United States and Ontario, Canada. This herbaceous perennial, exhibits a remarkable ability to colonize a wide range of natural areas often forming dense monospecific stands in old fields and forest understories. The lack of effective control strategies exacerbates the need for better understanding of the growth and reproductive potential of pale swallow-wort in invaded sites such that management tactics can better target susceptible phases of its life cycle. Based on a multi-year field trial in Jefferson County NY, effective management of pale swallow-wort may be challenging because of high seedling densities, rapid growth, and large seed output of established plants in invaded areas. Field collected plants of pale swallow-wort were found to readily establish associations with native arbuscular mycorrhizal fungi (AMF). The presence of AMF also increased survival and growth of pale swallow-wort seedlings and may also possibly have affected competitive outcomes between pale swallow-wort and common milkweed (Asclepias syriaca), a native Asclepiad. The implications of these findings for management of this invasive species will be presented.

5/12/05 - Carbon and Nutrient Dynamics and Land-cover Land-use Change in Amazonia: Selective Logging and Forest Regrowth Following Pasture Abandonment (Ted Feldpausch, PhD Candidate, Crop and Soil Sciences, Cornell University). Abstract: Selective logging and pasture formation have become dominant land-uses in Brazilian Amazon. As part of a larger study to evaluate the effect of logging and pasture formation and abandonment on C dynamics and nutrient stocks, forest structure, and forest regeneration potential, we conducted a series of experiments in central and SW Amazonia as part of the Large-scale Biosphere Atmosphere Experiment in Amazonia (LBA-Eco). This talk will focus on two topics, (1) carbon turnover and export during reduced impact logging operations, (2) nutrient limitations of forest formation following pasture abandonment.
The first topic (a) quantifies damage to the forest during logging; (b) relates logging damage to carbon export as whole logs, and turnover as canopy and understory disturbance and tree mortality from tree-fall, machine maneuvering, and road and patio building; (c) relates damage to canopy reduction in terms of leaf area index (LAI) and openness.
For the second topic, we examined the effect of P and Ca additions to soil on the growth and stand structure of forests growing on abandoned cattle ranches. We studied the emergence, development and death of over 3000 stems over three years in 10 forests 1 to 14-years after pasture abandonment. We compare our results to other Amazonian studies and offer recommendations to manage post-pasture forests, maintain C stocks and reduce logging damage. Our results have implications for remote sensing studies and computing a basin-wide carbon budget under land-cover land-use change scenarios.

5/19/05 - Nutrient Fluxes in Watersheds Under Maize-based Agroforestry Systems in Southern Malawi (Rebbie Harawa, PhD Candidate, Crop and Soil Sciences, Cornell University). Abstract: Malawis population has more than doubled in the past 20 years, while food production has remained unchanged, leading to a rapid decline in food production per capita. In the southern part of Malawi, the forested watersheds have been converted to agrarian watersheds where sediment and nutrient losses are accelerated. We therefore conducted a study with the overall goal of understanding the nutrient fluxes in agricultural watersheds, using three approaches: 1) Assessing balances of N, P and K for an entire watershed. In this module we compared inputs with outputs in two small agricultural watersheds and identified nutrient fluxes that are important in agricultural landscapes of southern Malawi. 2) Determining nutrient distribution for an entire watershed in relation to landscape position and land use. In this module we mapped the distribution of a range of soil chemical properties at 0-20 cm depth on a 20 m grid and tree density in a 15-ha watershed. 3) Studying nitrogen dynamics in different agroforestry systems as influenced by landscape positions. We studied the effect of landscape positions on maize yield and performance of different tree legumes (sesbania, gliricidia, tephrosia). Nutrient balances for an entire watershed calculated were positive for both watersheds which was attributed to more nutrient importation through mineral fertilizers and less nutrient export through stream flow and crop products than anticipated. Nutrient distribution was related to landscape positions with most of the nutrient accumulating in the lower slopes. Agroforestry cropping systems significantly increased maize yields, mainly through an improved nitrogen nutrition and availability in soil. The extent to which agroforestry cropping systems performed varied according to landscape positions, with sesbania remarkably adapted to the periodically inundated lower slopes, gliricidia in the mid-slopes and tephrosia fairing similar between slope positions.

Spring 2005 Special Seminars

3/4/05 - Using a Watershed Loading-Function Approach to Study Water Volume and Quality Under Current and Future Climate: A Pilot Study in South Australia (Dr. Jane Gillooly, Spatial Technologies Unit, CSIRO Land and Water, South Australia and Dr. John Hutson, School of Chemistry, Physics and Earth Sciences, Flinders University, South Australia). 10:00-11:00 AM, 135 Emerson Hall

5/16/05 - Mapping Plant Communities in Estuarine Environments: The Synergy of Applied Research and Extension (Susan Hoskins, Extension Associate/Image Analyst, Cornell Institute for Resource Information Science, Cornell University). Abstract: Characterization of tidal wetland plant communities in four marsh units of the Hudson River National Estuarine Research Reserve (NERR) is important for meeting monitoring, management and educational objectives of Reserve managers. Cornell Institute for Resource Information Sciences (IRIS) completed a comprehensive vegetation inventory using high resolution aerial photography collected in 1997. An existing 1991 inventory was prepared for comparison. The resulting inventory and multidisciplinary, multi-institutional expertise are instrumental to applied research and extension programs currently being conducted for NERR resource managers on the utility of satellite imagery for mapping and monitoring invasive species in the region. Advances in agronomic and environmental resource inventories require the integration of applied research and extension programs responsive and accessible to resource management professionals.

5/25/05 - Biotic Feedbacks to Land-use Change in Amazonia: The Trouble with Termites (Ilse Ackerman, PhD Candidate, Crop and Soil Sciences, Cornell University) 1:30 pm - 2:20 pm. Abstract: Landuse change alters resource availability and environmental conditions and can cause dramatic changes in the soil biota. In central Amazonia, mound-building termites become prevalent in post-clearing landscapes and constrain the re-colonization of the landscape by vegetation. At the study site, mounds occur at a high density of 760 mounds per hectare, occupying 3 to 15% of secondary forest area. To determine the most important constraints imposed by the termite mounds on plant establishment, this study investigated chemical, physical, and hydraulic properties of termite mounds at a central Amazonian secondary forest site and their effects on the development of native plant species. A second part of the study investigated carbon and nitrogen dynamics of these termite-modified patches. A third part of the study evaluated whether agroforestry systems at this same site were able to maintain the decomposer functional diversity of termites found in primary forest.

6/3/06 - Infrared Technology for Diagnostic Testing of Soil and Plant Health: Supporting the African Green Revolution (Dr Keith Shepherd, Principal Soil Scientist, World Agroforestry Centre-ICRAF). 11:00 am - 12:00 noon. Abstract: In a part of the world where millions of farmers still rely on hand tools to prepare the soil, agricultural researchers in East Africa are about to introduce a new high tech instrument that could set the stage for historic increases in food production. The new technology, infrared spectroscopy, is used to quickly analyze soil and plant samples at one per cent of the cost of conventional laboratory analyses. The process literally involves shining infra-red light on a soil sample to identify its composition. The seminar describes how the technology is being applied in Africa to (1) provide smallholder farmers with direct access to soil and plant testing for improved soil, crop and livestock management; (2) enable national agricultural laboratories to provide improved diagnostic services for agriculture and environmental monitoring; and (3) help governments prioritize resource allocation by revolutionalizing soil fertility and land degradation mapping capabilities.

FALL 2004

7/22/04 - Meeting the Needs: Food Security in Bangladesh with 140 Million Mouths and a Land Size of NC (Craig Meisner, CIMMYT Agronomist, CIMMYT Bangladesh). Abstract: Bangladesh with a population of 140 million and a land size of NC or 54,000 square miles, is the challenge as the experiment for the future of the world. If a country with a population the size of Bangladesh can 'make it', the future of the world is more secure. Come hear about the problems and challenges of food security for such a country including arsenic in the food chain, transgenic papaya and Calcium deficiency rickets and how Cornell and CIMMYT are working together to address these and many other sustainability problems in Bangladesh and South Asia.

8/26/04 - Using Trees to Remediate Tritium Contaminated Groundwater: a Modeling and Tracer Study (Karin Rebel, PhD Candidate, Environmental Information Science, Cornell University). Abstract: We have developed a spatially explicit model of water and tritium fluxes in the vadose zone in order to simulate water uptake and subsurface lateral movement in coniferous and mixed hardwood - coniferous forests on Coastal Plain soils of the southern United States. These Coastal Plain soils are characteristically sand overlying slowly permeable clays found at depths of 30 to 200 cm, and can form temporarily saturated, unconfined aquifers. Fifteen hectares of the modeled watershed was periodically irrigated with tritium enriched water. We used the tritium enriched water as a tracer to validate the model. The model was used to optimize irrigation, to evaluate the amount of tritium entering the atmosphere due to evapotranspiration and to quantify water and tritium fluxes in texture contrast soils.
Using tritium as a tracer, we have also studied how tree species and canopy position effect water and solutes uptake from different parts of the soil profile. We clipped branches to obtain leaf water from over-and understory laurel oak (Quercus Laurifolia) and over- and understory pine (Pinus elliottii and Pinus taeda), which was then analyzed for tritium. We found that for early successional trees (Pinus spp.) and trees in the overstory proportionally more water was taken up from deeper in the soil compared to the hardwoods or trees in the understory, which took up proportionally more water from the soil surface. These differences are important for understanding competition for resources within a forest and in predicting the hydrologic response to forest management practices such as thinning.

9/2/04 - Moving from Increased Agricultural Productivity to Improved Livelihoods (John Gaunt, Director, GY Associates Ltd, United Kingdom). Abstract: The presentation will describe and analyse the experience of research that sought to seek new knowledge of strategies for: 1. Effective delivery of rural services, and 2. Development of local institutional arrangements, that enable rural men and women, specifically including the poor, to improve their livelihoods through agriculturally based activities. The project teams were challenged to innovate within the research process. Achieving the outputs outlined above required:

• Research to be undertaken on a developmentscale
• Partnership between team members with academic and non-academic research backgrounds
• Learning platforms for actors with different perspectives to share and contribute to a common objective
• Interdisciplinary interventions and research that were not within the capacity of any single organization involved in the project.

9/9/04 - History of Cornell and the Development of the Brazilian Savannah (Cerrado) (David Bouldin, Emeritus Professor, Crop and Soil Sciences, Cornell University). Abstract: In 1969 Cornell received about a million dollars to do research on the fertility of the highly weathered soils in the tropics. A cooperative project was developed with North Carolina State, USDA- Puerto Rico and Brazilian ministry of Agriculture with funding from USAID; research was on location in Puerto Rico and Brazil. The major accomplishments were how to develop the yield potential of virgin soils, how to maintain the yield potential under cropping and how to extrapolate the results. Since the research was carried out, production of soybeans in the Cerrado has increased greatly. In my opinion several necessary conditions came together to produce this result; our research was only one of those conditions.
Currently we often hear that increases in future food production must occur by increasing yields on those soils now under cultivation. However there are huge areas of highly weathered infertile soils that are under developed. We must investigate how to use these soils and thus increase the amount of land available for food production. And our project illustrates the necessary frame work for such investigations.

9/16/04 - Mapping New York’s Foodsheds: A Spatial Analysis of Local Food Production Potential (Christian Peters, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Local food systems have been invoked to address many ills of modern agriculture. Proponents claim that increasing self-reliance on locally-grown food can, for example, improve the economic viability of agriculture, reduce consumption of fossil fuels used to transport food, and provide superior quality produce to surrounding communities. Though these claims may not all be of equal merit, sufficient evidence of their validity exists to warrant further investigation of the economic, environmental, and social benefits of local food systems. Examining food production potential of a region relative to its consumption serves as a reasonable point of departure.
The mapping of “foodsheds” is one way to estimate this potential. By using spatial data on soils, climate, topography, and land cover in conjunction with the Automated Land Evaluation System, maps of the physical and economic suitability of land for different classes of crops can be generated. These maps can then be queried in a Geographic Information System framework to determine the minimum distance within which the food needs of a population center could be supplied. The land encompassed within this distance is the “foodshed”.
In this project, the foodsheds of several upstate metropolitan areas will be mapped, and the distances compared based on population and the quality of the surrounding agricultural land. It is hypothesized that the food needs of Albany, Rochester, and Syracuse could be met within the boundaries of New York State.

9/23/04 - Improving Estimates of US Carbon Sequestration by Modeling Effects of Land Use Change on Soil Carbon from 1900 to 2050 (Peter Woodbury, Research Associate, Crop and Soil Sciences, Cornell University). Abstract: Land use change is an important driver of terrestrial carbon cycling in the US and elsewhere. We developed a book-keepingmodel of the effects of transitions between forest, agricultural, and urban land uses. Land uses changes such as afforestation have long lasting effects, so we developed historical data sets and ran the model beginning in 1900. Estimates of soil carbon stocks were derived primarily from the STATSGO database. Estimates of land use transitions were based on forest and agricultural inventories. Estimates of the effects of specific land use changes on soil and forest floor carbon fluxes were based on data from the literature. We are using the results of this model to improve the U.S. Greenhouse Gas Inventory, which is produced annually to meet reporting requirements under the United Nations Framework Convention on Climate Change. I will discuss some key model assumptions and how they influence model predictions and US terrestrial carbon flux estimates. Overall, our land-based estimates of terrestrial U.S. carbon net flux are near the lower end of the broad range of predictions from the recent TransCom3 atmospheric transport model inversions (Gurney et al. 2002, 2003, Law et al. 2003). Our improved land-based estimates of terrestrial US carbon stocks and net fluxes should help to constrain future estimates derived from ecosystem models and atmospheric models.

9/30/04 - Cornell’s Center for the Environment: Fostering Uncommon Opportunities (Mark Bain, Director, Center for the Environment, Cornell University). Abstract: The Center for the Environment specializes in crafting interdisciplinary collaborations among scientists and professors drawn from throughout Cornell and collaborating institutions. The Center’s specific objectives are to catalyze interdisciplinary and multi-institutional research on the environment, develop ways that environmental systems understanding can solve problems, connect Cornell’s environmental research capacity to needs around the world, and to engage Cornell’s scientific talent as new environmental issues and problems emerge. Current research concentrations address Great Lakes coastal ecosystems, the Hudson River and New York Harbor, and international sustainable development planning. Major initiatives are aimed at market mechanisms for conservation, hydrologic sciences, human and natural systems, environment of New York City, and sustainable ecosystem management.

10/7/04 - Biologically Intensive Agriculture: Renewing Earth and Its People (John Doran, Director, International Center for Sustainable Soil Fertility and Biointensive Agriculture and Professor Emeritus Agronomy and Horticulture, University of Nebraska-Lincoln and John Beeby, Manager, Molecular Diagnostic Laboratory, Animal Health Diagnostic Laboratory, Cornell University). Abstract: Scientific and technological advancements over the past half century have increased global production of food grains by over three-fold. However, large scale industrial approaches to agriculture are not meeting the basic food security needs of over 800 million people, mostly the poor and disenfranchised. Increased inputs of chemical and fossil fuels in agricultural systems have also resulted in land and environmental degradation and exclusion of the poor from food production using these technologies. We must find resource friendly ways to meet food production needs while maintaining environmental stability and conserving resources for future generations. Biologically intensive agriculture can meet the needs of the poor and disenfranchised and also maintain environmental quality and conserve natural resources. One small scale agricultural system, GROW BIOINTENSIVE, can produce green revolution type yields in small areas (< 0.1 ha) using only locally-available resources. This is done through use of double-dig, carbon-rich and legume compost crops, intensive crop planting, and use of compost. Compared to conventional agriculture this system can use 70 90% less water, 50 100% fewer purchased inputs, and 99% less energy. This system also greatly rebuilds eroded and depleted soils. Over the past three decades this system of farming has been effective in over 130 countries, resulting in meeting the basic nutritional and caloric needs of people while conserving or building soil, environmental, and natural resources.

10/14/04 - The Effects of Soil Solarization on the Microbial Community in Nepal’s Rice-Wheat Cropping System (Steve Culman, Master Student, Crop and Soil Science, Cornell University). Abstract: The Rice-Wheat cropping systems of the South Asian Indo-Gangetic Plains currently feed over one billion people. In the last thirty years continuous cropping has exacerbated the problems of weeds, pests and diseases and the subsequent decline in yields in some regions. Soil solarization is an assessable management practice that has been shown to help ameliorate these problems. It involves passively heating the soil with polyethylene sheeting several weeks prior to planting rice. Field trials in Nepal were conducted to determine the effects of soil solarization on the microbial community in rice and wheat. Results from both field and molecular data will be discussed in this presentation.

10/21/04 - Agricultural Systems in Tibet’s Crop Dominated Production Zone (Peter Hobbs, Professor Adjunct, Cornell University). Abstract: The irrigated, crop dominated production zone along the alluvial plains of the Yalong-Tsampo river is Tibet's granary representing 50% of cropland in Tibet. Food self sufficiency in cereals occurs in this zone where cropping accounts for 75% of agricultural value. Livestock are also an important component in the farming systems in this area and make up the additional value of agricultural products. This zone is deficit in animal feed. This seminar will present the findings of a FAO consultancy to Tibet this past summer. The goal of this consultancy was to evaluate the feasibility of double cropping and increased fodder production. Changes in Tibetan agriculture and development after the Chinese cultural revolution will also be explored.

10/28/04 - Eco-hydrological Modeling at the Landscape Scale: Recent Trends and Future Challenges (Dr Karsten Schulz, Department of Applied Landscape Ecology, UFZ - Centre for Environmental Research Leipzig, Germany). Abstract: In this contribution I will explore the potentials but also the limitations of using remotely sensed data within eco-hydrological process descriptions. Being an indirect measurement influenced by atmospheric conditions, large uncertainties have to be expected when biotic and abiotic land-surface characteristics are derived from spectral information. Another related issue covered here will be the problem of scale and parameter scaling. While process descriptions are usually derived from lab experiment on very small spatial scales, they often need to be applied at much larger grid sizes ranging from a few meters to several hundred km. Thus effective parameterisations representing all the non-linearities present at the smaller scale need to be derived, leading to an identification problem (parameter “equifinality”) for complex process descriptions in the calibration procedure.
Both problem areas - data uncertainty and the scale/scaling problem - need to be addressed in future landscape-scale eco-hydrological predictions and some solution strategies will be presented.

11/4/04 - No Seminar

11/11/04 - Soil Fertility as an Ecosystem Concept (Cheryl Palm, Senior Research Scientist, Tropical Agriculture Program, The Earth Institute, Columbia University). Abstract: Soil science contributed to the early development of ecosystem concepts largely through the work of Hans Jenny yet agricultural research moved from this holistic base to more reductive and substantially empirical approaches. Soil, crop, and pest management practices are developed as separate technologies and their impacts on the function of other parts of the ecosystem often ignored. A proposed framework for the integrated management of soils includes components of agroecosystems (soils, biota, vegetation, and people) and the processes that link those components. There are generic, underlying biogeochemical processes that describe the processes and interactions among components. Testing a set of hypotheses on changes in soil and ecosystem properties and processes that result from management interventions of the different components is a means of establishing these links. Ultimately people are the key to sustained management of soils and agroecosystems. The selection of agroecosystems types and management practices is determined by livelihood and production goals combined with farmer assets, including natural, financial and human capital. A target for research is to identify the set of possible agroecosystems and management practices within the human and environmental contexts that meet the joint aims of the livelihood goals of the farmer and a sustained natural resource base.

11/18/04 - The Role of Black Carbon in Soil Organic Matter Properties of Amazonian Dark Earths (‘Terra Preta’) (Biqing Liang, Graduate Research Assistant, MSc Student, Crop and Soil Sciences, Cornell University). Abstract: Terra Preta soils are anthrosols showing high fertility and high organic C contents neighboring otherwise highly weathered soils of the humid tropical Amazon Basin. These soils are said to be created thousands of years ago by pre-Columbian native populations. A significant enrichment with Black Carbon (BC) is proposed to be the key for their observed high cation exchange capacity and organic matter contents. I studied the surface chemical properties of BC using synchrotron-based NEXAFS (Near Edge X-ray Absorption Fine structure Spectroscopy) and STXM (Scanning Transmission X-ray Microscopy) techniques and found significant amounts of carboxylic groups on the surfaces of BC, and an increasing level of oxidation from the core of BC particle to surface. Such oxidation indicates BC degraded slowly, with a life-time of thousands of years. Additionally, labile soil organic C may be stabilized on the surfaces of BC particles. A soil incubation experiment with sugarcane (using the natural 13C discrimination of this C4 plant) was conducted to examine the fate of added C by isotopic differentiation, which helps to elucidate the hypothesis that BC can stabilize soil organic C.

11/25/04 - No Seminar

12/2/04 - Microbial Ecology of Compost Amendments in Organic Agriculture: I. Monitoring human pathogens in compost tea; II.-Bacterial communities in vermicompost and thermophilic compost (Allison Horner, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Organic agriculture relies entirely on non-synthetic forms of nutrient amendments and pest control, compost being one of the more common amendments. The recent rise in popularity of organic agriculture has led to the implementation of federal guidelines through the USDA National Organics Program (NOP). Drafting legislation to regulate the production and use of compost has been difficult given the lack of general scientific information available in this field.

1. I. Compost tea is promoted for its plant disease suppressive properties, but the current NOP guidelines do not allow for its use given concerns over the potential food safety risk. Many practitioners use nutrient amendments such as molasses when brewing aerated compost teas and recent research has shown that molasses additions can increase the re-growth of human pathogens such as E. coli and Salmonella. Results of a study on molasses additions and E. coli in Aerated Compost Teas will be discussed.
2. II. Vermicompost is the product of a mesophilic decompositions process that is distinct from traditional thermophilic compost. Few comparisons have been made between the two types of compost, their microbial communities and their positive effects on plants. A field trial was carried out with organic tomatoes to evaluate the performance of various organic amendments for both their plant growth promoting and disease suppressive qualities. Results from this field trial and the molecular fingerprinting of bacterial communities in composts will be discussed.

Fall 2004 Special Seminars

11/29/04, 4:00-5:00 PM, 135 Emerson Hall - Effect of post-pollination water deficit and shade on maize kernel set: changes in sugar, ABA, cytokinins and invertase gene expression in the placenta/pedicel tissue (Kanishka de Silva, MS Candidate, Crop and Soil Sciences, Cornell University). Abstract: Maize grain yield is often affected by environmental stresses such as drought and shade that limit photosynthetic assimilate flux. Treatments that decrease the assimilate supply particularly during grain filling, substantially reduce maize grain yield due to abortion and decrease in endosperm dry matter accumulation, especially of kernels in apical ear regions. Placenta and the upper pedicel tissues at the base of individual kernels serve as the site of assimilate unloading and post-phloem transport. It was postulated that during stress, changes in these tissues might contribute to the loss of kernel set, particularly at the apical region of the ear. Greenhouse grown maize was subjected to water deficit and shade treatments from 2 to 9 days after pollination. Water deficit and shade significantly reduced kernel number and kernel dry matter accumulation particularly at the apical ear region with the most severe effects in the shade treatment. Placental starch reserves were almost depleted by the end of stress period in both treatments. In addition, water deficit showed a very low hexose to sucrose ratios during stress both in basal and apical kernels while in shade treatment, the values were comparable to controls. Relative mRNA levels of Incw2, a gene which encodes the key assimilate processing enzyme cell wall invertase in maize placenta, were determined using northern blot analysis and were found to be significantly low in water deficit treatment, particularly in apical kernels. To determine whether the stress-induced hormone ABA and the cytokinin hormone zeatin had any influence on kernel set, amounts were quantified by enzyme-linked immunosorbent assay (ELISA). Water deficit increased the concentrations of ABA and decreased zeatin both in basal and apical placental tissues. Shade also increased the placental ABA levels but to a lesser extent compared to water deficit. These findings suggest that different mechanisms may be involved in maize placenta contributing to kernel loss under water deficit and shade.

Conferences

Other Related Seminars

Biogeochemistry and Environmental Change

Department of Natural Resources