Seminars

Welcome to the Crop and Soil Sciences Seminar Series. Following is a list of the scheduled seminars for the 2007-08 academic year. Unless otherwise noted, all seminars are on Thursday, from 12:20 PM to 1:10 PM in 135 Emerson Hall. Please contact Lin Marco (lm69) or 5-1410 to reserve a slot.

Crop and Soil Sciences

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05/08/08 - Impact of nutrient management, planting date, and location on papaya yield and quality in Bangladesh (Jackie Greenwood King, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: In rural Bangladesh, an estimated 30 to 50% of children and women of reproductive age are deficient in vitamin A. One strategy to improve the nutritional status of these individuals is to increase the production and availability of vitamin-rich fruits and vegetables. Papaya is cultivated throughout Bangladesh and is an important source of vitamin A (i.e., provitamin A carotenoids), vitamin C, and folate. Over a two year period, six field experiments at two different sites (i.e., Pabna and Rangpur) were conducted in an effort to improve papaya production in Bangladesh. This study evaluated the effect of lime, manure, and micronutrient application on plant nutrition, soil properties, fruit yield, and the vitamin content of papaya. In addition, the impact of planting date and location on papaya production will be discussed.

FALL 2007

08/30/07 - Role of biological nitrogen fixation in replenishing soil nitrogen in cropping system (JK Ladha, PhD, Frosty Hill Fellow, Crop and Soil Sciences, Cornell University) Abstract: For an agro-ecosystem to be in N equilibrium, the sum of N inputs should be equal to the sum of N outputs. Among various inputs and outputs, inputs from BNF and fertilizer sources and outputs through losses are the most important. The magnitudes of N gains from BNF and losses from denitrification and the subsequent capacity of a system to maintain an equilibrium will be discussed in two major groups of lowland rice-based cropping systems with large differences in soil moisture contents and cultural management.

09/06/07 - More crop per drop: Examing soil fertility constraints in water saving rice systems (V Ryan Haden, PhD Student, Crop and Soil Sciences, Cornell University). Abstract: Against the backdrop of global water scarcity, there is a need to consider novel technologies for reducing water inputs for rice production. Aerobic rice is one approach that has the potential to reduce water use but rarely without yield penalties. To address these trade-offs our research will examine how a shift from flooded to aerobic soil conditions affects N and P fertility.

09/13/07 - Use of visible and near infrared spectroscopy for the assessment of soil health indicator properties (Judith Ball, Graduate Student, Crop and Soil Sciences, Cornell University). Abstract: Promoted as rapid and nondestructive, Visible and Near Infrared (VNIR) Diffuse Reflectance Spectroscopy is an analytical technique utilizing radiant energy in the range of 350-2500nm that correlates the reflection of near-infrared radiation with constituent properties of the sample material. In an effort to develop a soil test that is both cost-effective and agronomically meaningful, VNIRS was explored as a potential alternative analytical method to the more costly and time-consuming laboratory analysis involved in soil health assessment which requires several days to complete. Additionally, VNIRS was investigated as a potential method for assessment of soil salinity using soil samples from the ChokwÃ© Research Station located in Mozambique.

09/20/07 - Organic Chemicals in Sewage Sludges (Ellen Harrison, Director, Cornell Waste Management Institute, Crop and Soil Sciences, Cornell University; Co-author: Anthony Hay, Associate Professor, Microbiology, Cornell University) Abstract: The majority of U.S. sewage sludges, a by-product of wastewater treatment, are applied to land as a soil amendment. There are risks and benefits associated with the nutrients, organic matter, chemical contaminants and pathogens they contain. Current regulations do not address organic chemicals, and many of these concentrate in the sludges. A review of the literature found 516 organic chemicals reported in sludges and many of those are found at concentrations exceeding USEPA soil screening levels, raising concerns about the risks they pose. Earthworm bioassays are a useful tool for assessing toxicologic impacts.

09/27/07 - High-resolution climate data: Its development and application (Art DeGaetano, Professor, Earth and Atmospheric Science, Cornell University/Director, NOAA Northeast Regional Climate Center AND Jeff Melkonian, Senior Research Associate, Crop and Soil Sciences, Cornell University) Abstract DeGaetano: The recent and historical climate data record is based on observations from a relatively low density network of meteorological stations. Efforts to interpolate these data to the finer resolution needed to make location-specific agricultural and environmental management decisions has typically relied on a variety of statistical interpolation techniques. As part of the Computational Agriculture Initiative we have developed a hybrid method of data interpolation that relies of meteorological forecast model initializations and radar estimated rainfall amounts. For both methods the initial spatial field is specified the gridded forecast or radar values. Station observations are then used to identify the magnitudes and spatial structure of errors in the model (radar) fields which are subsequently used to adjust the gridded data. Model-based information regarding the change in temperature with height is used to interpolate temperature fields to a 5 km resolution. Precipitation data are maintained in the native 4 km radar resolution. We show that via this method interpolation accuracy exceeds that of several commonly used statistical interpolation routines. The high resolution climate data produced for the Comp Ag Initiative are archived in a relational database at the Cornell Theory Center. The data are available to researchers via a web service. Abstract Melkonian: Weather affects the size of the early season soil nitrogen (N) pool, contributing to the well-documented variability in economic optimum in-season N rates for maize. To estimate weather-mediated changes in the early season soil N pool, we adapted two existing dynamic simulation models to develop a well-calibrated model of soil/maize cropping systems (Precision Nitrogen Management or PNM model). We have used the PNM model to track early season soil N and adjust in-season N rates accordingly for the different climate regions in New York State. By linking the PNM model with high resolution climate data provided by the Northeast Regional Climate Center with support from the Cornell University Center for Advanced Computing, we will be able to move from region-wide in-season N rate recommendations for maize to farm- or field-specific in-season N rate recommendations. Users (producers, crop consultants and extension staff) will be able to obtain these recommendations by providing relatively simple information on location, soil type, cultivar, and N additions (organic and inorganic). The web interface and linkage to high resolution climate data will be discussed.

10/04/07 - Stability of Biomass-Derived Black Carbon in Soils (Biqing Liang, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: Black carbon (BC) may play an important role in the global C budget, due to its potential to act as a significant removal (sink) of atmospheric CO2. In order to fully evaluate the influence of BC on the global C cycle, a sound understanding of the stability of BC is required. The longevity and chemical stability of BC was assessed in a chronosequence of high-BC containing Anthrosols from the central Amazon, Brazil, using a range of spectroscopic and biological methods.

10/11/07 - Apportioning agricultural carbon credits to mitigate global warming (Steve Gilman, Ruckytucks Farm, Stillwater NY; Policy Coordinator, Northeast Organic Farming Association - NOFA) Abstract: After years of inattention, obfuscation and denial -- energy and climate change have emerged as leading issues of our time, with today’s agriculture implicated as a major fossil fuels user and greenhouse gas generator. There is substantial documentation, however, that a shift to organic farming practices which routinely replace fossil fuel inputs with biological ones and sequester atmospheric carbon in soil organic matter have the potential to significantly ameliorate both concerns, while providing a non-subsidized, carbon credit income stream for farmers who undertake these environmentally beneficial practices. Thus far, organic agriculture's contribution to the mitigation of energy use and global warming largely remains overlooked and unrewarded. This seminar looks into the current status of these issues, as well as the need for establishing science-based criteria for agricultural carbon credits.

10/18/07 - Changing soil water and oxia regimes and their implications for nutrition of rice (Richard Bell, Professor, School of Environmental Science, Murdoch University, Perth, Australia) Abstract: This seminar will draw on research conducted on nutrient availability in the rainfed lowland soils of Cambodia, and more recent work we've done on physiology of rice roots under changes in root oxygen supply. The implications of the results for rainfed lowland rice and for water saving rice production systems will be discussed.

10/25/07 - The fate of nitrogen in grain cropping systems: A meta-analysis of field experiments using stable isotope methods (Jennifer Gardner, MS Candidate, Crop and Soil Sciences, Cornell University). Abstract: A meta-analysis of primary literature was conducted to investigate the effects of environment and agricultural management practices on the fate of nitrogen (N) in crops, soil, and various loss pathways of the N cycle. Meta-analysis is a robust statistical technique for analyzing and synthesizing the results of a collection of studies addressing similar questions. The database includes 15N studies in temperate grain production systems as a subset of the vast research on N management in agroecosystems. The effect of practices targeting crop uptake of N is compared to practices targeting multiple processes of the N cycle. The fate of labeled inorganic and organic N additions is also compared. In addition, the work analyzes the current status of the agronomic literature in terms of its ability to address ecological questions.
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Black carbon (BC) stability: Effects of its intrinsic properties and environmental factors (Bihn Thanh Nguyen, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: BC-derived carbon constitutes a significant proportion of soil organic carbon despite of a small amount of BC formed annually. In environments, BC could persist up to ten thousands of years, forming an important carbon pool, sequestrated from atmosphere. BC eventually decompose, however, following 2 mechanisms of biotic and abiotic degradations. The stability of BC is a function of its quality and environmental factors, which are investigated in the current study. Molecular and elemental characterizations at nano-scale are conducted to examine changes in intrinsic properties of BC materials in response to environmental variation.

11/01/07 - Effect of farmer decision making on biophysical and economic outcomes in integrated crop-livestock systems in Yucatan, Mexico (David Parsons, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: The rural poor of the Yucatan Peninsula, Mexico, rely primarily on shifting cultivation in forested areas to generate income from crop and livestock production. First, a field experiment involving the addition of herbicides and small ruminant manure was undertaken to address yield decline in a traditional maize production system. Second, a dynamic simulation model was developed to describe nutrient flows in and out of farms and between farming system components. Results from the scenarios constructed and analyzed show the benefits of having mixed crop-livestock systems, and also the biophysical and economic outcomes from a range of livestock feeding practices.

11/08/07 - NO SEMINAR

11/15/07 - Accounting for surface roughness and moisture content in the diffuse near-infrared sensing of soils (Chun-Yu Wu, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: Near-infrared sensing of soils is attracting a lot of attention, in part because of the possibilities it offers for remote sensing of soil carbon and for the development of tractor-mounted sensors for use in precision agriculture. However, to meet either objective, one needs to be able to cope with the fact that soil, in the field, unlike the sieved, air-dry soil samples used in the laboratory, are moist and have an uneven surface.The research presented in this seminar shows the effect of these two features on NIR spectra of five different soils, and points to ways both moisture and surface roughness could be taken into account explicitly in the analysis of spectra for other parameters.

11/22/07 - NO SEMINAR - THANKSGIVING RECESS

11/29/07 - Cassava drought tolerance mechanisms re-visited: Evaluation of drought tolerance contrasting Cassava varieties under water stressed environments (Luis Duque, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: Cassava (Manihot esculenta Crantz) is one of the most important staple foods in the human diet in the tropics, cultivated in areas considered marginal for other crops. Because of its remarkable tolerance to drought and great ability to survive uncertain rainfall patterns, it is considered a contributor to food-security against famine, requiring minimal inputs and making it an important crop for drought prone areas of tropical and sub-tropical Africa, Asia and Latin America. This effort aims to establish the best traits to be used in breeding programs for drought tolerance by elucidating the mechanisms of cassava’s remarkable tolerance to drought such as non-structural carbohydrate partitioning and remobilization, abscisic acid (ABA) accumulation, leaf retention, leaf canopy temperature and root growth among others for the development of a more cost-effective breeding process for drought tolerance that can be used for cassava and other crops.
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Tools for evaluating the nitrogen (N) needs of corn (Zea Maize L) (Joseph Lawrence, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Field crop production in NYS is dominated by grain crops and forage crops produced to support the dairy industry. Precision nitrogen (N) management has become a very important topic for producers who are trying to combat unstable and rising fertilizer prices as well as environmental challenges. The main sources of N on the farm are animal manure, sod N, soil organic matter N and inorganic N fertilizer. Work performed over the past several years by the Nutrient Management Spear Program has focused on testing of various tools for environmentally sound use of on-farm N resources with the goal of only supplementing with fertilizer N where needed for optimum crop production. . This seminar will focus on N needs for corn over a rotation with sod, testing and calibration of two tools for N management (the Illinois Soil Nitrogen Test (ISNT) and the Late-season Stalk Nitrate Test), and the impact of different manure incorporation tools on N conservation.

SPRING 2008

01/31/08 - Agricultural production in North Africa and Central West Asia: A region with permanent drought risk (Kawther Latiri, Agronomist, Institut National de Recherche Agronomique de Tunisie, Tunisia) Abstract: Agricultural Production in CWANA region (Central West Asia and North Africa region) takes place in a difficult context with very limited natural resources. Drought is a permanent risk and is expected to intensify due to climate change. The presentation is based on the IAASTD work (www.agassessment.org), it shows the main achievements of agricultural production during the last 50 years with its constraints, its consequences on natural resources and its challenges for the future.

02/07/08 - Applications of synchrotron-based FTIR and X-ray spectromicroscopy for understanding anthropogenic and climatic influences on soil biogeochemistry (Dawit Solomon, Research Associate, Crop and Soil Sciences, Cornell University) Abstract: Human activities have fundamentally altered many of the Earth’s biogeochemical cycles, the most prominent of these changes being manifested by modification of the global C cycle. This presentation an overview some of the efforts made by the biogeochemistry group of the department: (i) to identify and fingerprint the functional group composition of organic matter, and (ii) to investigate the long-term impact of anthropogenic land-use and land-cover changes and some climatic parameters on the amount and molecular-level composition of SOM and associate elements in various ecosystems across the globe using a variety of specromicroscopic techniques.

02/14/08 - Bioenergy and greenhouse gases: Research highlights and needs in crop, soil, and environmental sciences (Cornell Panelists: Introduction/New York Land Resources for Bioenergy Feedstock Production, Peter Woodbury, CSS; Overview of Northeast Sun Grant Bioenergy Activities, Corinne Rutzke, BEE; Best Agricultural Strategies to Reduce Fossil Fuel Use and GHG Emissions, John Duxbury, CSS; Grass Combustion Bioenergy Systems, Jerry Cherney, CSS; Evaluation of Perennial Grasses for Biofuel Feedstock, Hilary Mayton, PBG; Environmentally Friendly Bioenergy with Biochar, Johannes Lehmann, CSS; Climate/soil Interactions on Coppiced Willow and Grass Biomass Productivity, Jeff Melkonian, CSS; Maize as a Bioenergy Feedstock: Soil Quality and Nitrogen, Harold van Es, CSS; Integrating Multidisciplinary Plant Bioenergy Research at Cornell, Joss Rose, PBG; Permanent Raised Beds: Adapting Rice-Based Cropping Systems to Climate Change, Julie Lauren, CSS; Conservation Agriculture: The Implications for GHG Emissions, Peter Hobbs, CSS; CURBI: A Concept for Bioenergy at Cornell, Drew Lewis, Experiment Station) Abstract: Bioenergy and greenhouse gas emissions are hot topics in the popular press as well as scientific journals, and crop and soil scientists are key players in finding solutions to these concerns. This “potpourri” session will feature 12 researchers and program managers from Crop and Soil Sciences and other departments at Cornell University. Each will present a 5-minute “snapshot” of their work related to bioenergy and greenhouse gases. These will be followed by a panel discussion to discuss research and educational needs for bioenergy and greenhouse gases. (Note time change: 12:20-2:00 pm)

02/21/08 - Strategies for engineering plants for phytoremediation, human health and bioenergy (Om Parkash, Assistant Professor, Plant, Soil and Insect Sciences, University of Massachusetts, Amherst)

02/28/08 - Eating local: Different perspectives - A panel discussion (Moderated by Ellen Harrison, CSS, Cornell University; and featuring Professor Joe Regenstein, Food Science Department, Cornell University; Jennifer Wilkins, PhD, Division of Nutritional Sciences, Cornell University; and Ken Goodwin, Wegman's) Abstract: "Buy local" is a growing trend. Consumers are aware of the benefits, but there are issues and concerns as well. Food quality and energy costs of local food are not always favorable. The panel will explore the benefits and downsides from several perspectives, including what a local supermarket is doing to work with local suppliers.

03/06/08 - Assessing the effects of Bt/Corn and insecticides on decomposer organisms, plant residue carbon turnover and Bt/protein in soil (Kai Xue, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: With the rapid adoption of Transgenic plants(TPs), more and more concerns has been raised on their potential environmental effects. This debate has lead to our study on evaluating the impacts of Cry3Bb corn, designed to managing corn rootworm without spraying insecticides, on aspects of plant carbon allocation, decomposition, microbial community of decomposer and the fate of /Bt/ protein. Till now, all our results indicate that differences in the variables we measured were driven by environmental factors primarily, rather than by any innate differences between the corn hybrids tested.

03/13/08 - Soil microbial community response to amending soils with biochar (Hongyan Jin, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: Microbial communities in soil can be very sensitive to biochar amendment. Biochar specific properties, affinity to nutrients and microorganisms and long-term stability, complicate interactions between biochar and microorganisms. On one hand, soil microbial community may be affected by the quality and quantity of the biochar amendment. On the other hand, microorganisms may have a biodegrading effect on the quantity and properties of the biochar. Furthermore, the interactions between biochar and microorganisms will remarkably affect nutrient cycling and nutrient availability both to microorganisms and to plants grown in biochar amended soils. Based on previous research on amending soils with biochar, we are studying the effects of biochar on the activity, abundance and composition of microbial populations, the exoenzymatic activities and the specific microbial communities colonizing on biochar particles in biochar amended field trials conducted in Aurora, NY, USA, in 2007 and Hangzhou, China, in 2006.

03/20/08 - NO SEMINAR - SPRING BREAK

03/27/08 - Restoration of soil organic matter in smallholder farming systems of Western Kenya (Joseph Kimetu, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: The study focused on improvement and stabilization of soil organic matter with the use of organic fertilizers of differing quality and the influence on food production and security in highly degraded tropical soils of western Kenya (Vihiga, Nandi, Kakamega districts). The synergistic effects of organic and inorganic fertilizers on crop production were as well monitored over a two-year period. Farmers will use the obtained research outputs to adapt the management of their cropping systems to mitigate soil C losses or even increase SOM, conserve N capital, increase use efficiency of fertilizer nutrients and sustain food production.

04/03/08 - Using hyperspectral soil reflectance and spatial statistics for soil characterization (Ali Volkan Bilgili, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: Soils often show high spatial variability within and across fields, which requires the analysis of large sample sets to estimate global or local means, which may be prohibitively expensive with conventional laboratory techniques. Diffuse Reflectance Spectroscopy shows great promise for rapid and inexpensive assessment of soil physicochemical and biological properties both in the laboratory and in situ. This seminar discusses applications of Visible–Near (VNIR) and Mid infrared reflectance to predict various soil properties of soil samples collected from a single field in semiarid Turkey. The methodology was also tested for its feasibility to quantify soil P sorption capacity and to estimate soil salinity parameters.. It was concluded that several important soil variables used in environmental modeling can be predicted successfully using this methodology and that its combination with geostatistical methods allows for cost-effective soil mapping.

04/10/08 - Exploring black carbon dynamics in soils (Karen Heymann, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: Black carbon (BC) is ubiquitous in terrestrial ecosystems, comprising a significant proportion of the terrestrial carbon (C) pool and mitigating many important biogeochemical processes. Black carbon describes a range of pyrogenic substances which exist along a continuum from combustion residues such as char, to combustion condensates such as soot, and which originate from either plant biomass or fossil fuels. Synchrotron radiation offers new opportunities to obtain information about bulk organic materials by overcoming limiting factors such as structurally destructive sample preparation. Taking advantage of advanced spectroscopic techniques will offer new insights into BC characterization, BC quantification in soils, the role of BC in the formation of black humic acids, and the mechanisms controlling the molecular interactions of BC and minerals in soils. Understanding the role of BC in terrestrial ecosystems is essential to elucidating various mechanisms controlling the stability of soil C pools, the fate of pollutants, and the composition and quality of soil organic matter.
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How can maize yields improve during drought conditions? A look at the underlying physiology of Zea mays during the flowering period (Amanda Solliday, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Water scarcity has become an increasingly salient issue as our world population continues to grow. Of the many potential abiotic stresses, insufficient water supply is the major limiting physiological constraint for crops in many areas. Because many variable phenotypic characteristics are included in the overall quantity known as “yield”, plant breeders experience difficulties when selecting lines for higher yield under drought conditions. The use of other measurable traits, such as reproductive timing or concentrations of stress hormones, can reveal information regarding changes in plant behavior during low water availability. This seminar focuses on deciphering the physiological signaling behind the drought response of maize and identifying responses that characterize reproductive success (i.e. high yields) under water stress.

04/17/08 - Differences in soil properties and food web structure following 75 years of high-input wheat versus no-input harvested prairie meadows in Kansas (Steve Culman, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: Soil ecosystem properties and processes which simultaneously maintain native fertility and sustain plant yields are of principal interest in sustainable agriculture. Native prairies in Kansas are relevant in this context, as they have been annually hayed with no fertilization or detectable decline in yield or soil fertility. In contrast, intensive wheat production has resulted in significant reductions in soil fertility and now requires intensive inputs to maintain yield. This study identified differences in soil properties and soil biological communities between these perennial grasslands and adjacent annual wheat fields. These differences and their implications on nutrient cycling and plant yield efficiencies will be discussed.

04/24/08 - Arsenic contamination in ground water and soils: spatial variability and its effect on arsenic uptake, speciation, crop growth and grain yield in rice (Oryza sativa) (Zia Ahmed, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: The direct effect of As in irrigation water and soils on As accumulation in rice grain is uncertain since As accumulation in crops is a function of complex interactions between soil, plant and environmental factors. No distinct relationships were observed between As content in ground water, soil and rice grain content for 264 samples collected from Tala Upazilla, Satkhira District Bangladesh. No clear similarities were visualized among the ordinary kriged maps of water, soil and grain arsenic content. The estimates of spatial uncertainty of arsenic in three sources were in following order: soil > grain > water. However, map qualities of soil and rice As can be improved by regression kriging taking into account the relationships of soil and grain As with auxiliary variables. The effects of genotype and environment on rice grain arsenic content were evaluated for 20 boro (dry season) and 18 t.aman (wet season) rice varieties grown in 10 locations across Bangladesh. Most of the variation in grain arsenic content was explained by the environment. The key soil variables controlling grain As were: pH, amorphous-Fe, phosphate extractable-As, and water extractable-As. Eighteen dry season rice varieties from Bangladesh and 2 from the USA were grown in high (53 mg/kg) and low (7 mg/kg) As soil in a greenhouse at Cornell University. Growth and yield of all varieites, except one from the USA, were suppressed in the high As soil. Only 5 Bangladeshi and the 2 USA genotypes were able to produce significant amounts of grain, and grain As concentrations were very high. All short duration genotypes performed better than long duration varieties in terms of growth and grain yield. Fairly high As concentrations in rice grain and significant genotypic variation were observed when rice was grown in the low As soil. Speciation of As in grain of selected rice varieties grown at two locations in Bangladesh and at Cornell showed that arsenite was dominant at low grain total As concentrations but dimethylarsinic acid (DMA) was dominant at high grain As concentrations. The occurrence of high levels of DMA in grain of all genotypes can be explained by methylation of inorganic As within the plant to adapt to an As contaminated environment or by uptake of DMA produced by microbial methylation of As in highly reduced soil.

05/01/08 - Germination, emergence, and performance of pale and black swallow-wort on two New York soils at various pH levels (Lillian Magidow, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Pale swallow-wort and black swallow-wort are two herbaceous, perennial vines which are increasingly problematic invaders in the Great Lakes Basin of the Northeastern U.S. and Southeastern Canada. Their North American ranges rarely overlap and it is hypothesized that soil type and pH may play a large role in their distribution. To examine the effects of soil type and pH on pale and black swallow-wort emergence and growth, two experiments were conducted. One was a common garden experiment that brought soil and swallow-wort seed from two heavily infested sites in NY back to Ithaca. Soils were treated to three pH levels and arranged in a RCB design. Swallow-wort seed were sown in the pots in 2005 and 2006 and monitored for various growth parameters. The second experiment was conducted in a growth-chamber in 2007 using the same soil and swallow-wort seed as the common-garden experiment. Soils were treated to 12 pH levels and incubated for 15 weeks. Swallow-wort seed were sown on the soils and germination was recorded for 14 days. The majority of treatment effects were due to species differences. A given species could be observed to perform well in its own soil for one growth parameter and well on the reciprocal soil for another parameter. The responses to pH were also inconsistent, although growth was poorest for all parameters at extremely low pH. These inconsistent results suggest that habitats of varying soil type and pH may be equally suitable for colonization by swallow-wort, and that the growth and spread of these species are influenced by other factors. This conclusion is borne out by mapping data in which both species appear on a wide range of soil types and pH values, leaving unanswered the question of what factors determine their current and potential ranges.
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Assessing recalcitrant properties of BC in both field and incubation experiments (Binh Thanh Nguyen, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: BC-derived carbon constitutes a significant proportion of soil organic carbon pool despite of a small amount of BC formed annually. Although stable, it eventually decomposes, depending on local environmental conditions. Three experiments, one from agricultural field and other two water regimes and temperature-controlled incubation experiments were conducted to investigate BC dynamics and properties. Results from 2 incubation experiments would be presented and discussed.

Other Related Seminars
Biogeochemistry and Environmental Change
Natural Resources
Plant Breeding

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