Welcome to the Crop and Soil Sciences Seminar Series. Following is a list of the scheduled seminars for the 2008-09 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

SPRING 2009

01/29/09 - Conventional wisdom vs. reality: misconceptions about soil pH buffering, N soil testing, soil organic matter, and agricultural development (Fred Magdoff, Emeritus Professor, Plant and Soil Science, University of Vermont and Adjunct Professor, Crop and Soil Sciences, Cornell University) Abstract:  Over the years I have found that conventional wisdom about a number of issues was contradicted by what actually happens in the real world. A number of these misconceptions will be discussed, including a) soils are most well buffered around pH 5.5, b) soil nitrate behavior is so dynamic it cannot be used as an indicator of plant available N in humid regions, c) soil organic matter is of minor significance, and d) agricultural development in poor countries occurs best by letting the "free market" take care of it. Possible reasons for the origin of the misconceptions will also be discussed.

02/05/09 - Biochar: basic concepts and new developments (Johannes Lehmann, Associate Professor, Crop and Soil Sciences, Cornell University) Abstract: Biochar has been touted as a strategy for sustainably improving soils while sequestering carbon for the long term. The compelling evidence of Amazonian Terra Preta soils is a testament to its longevity and lasting fertility effects. The empirical evidence for key properties of biochar have by now been explained. The high cation exchange capacity is a function of both high surface area and charge density and the stability is a function of both the chemical and physical properties of the aromatic structure. What appeared to be a static behavior, however, was in fact found to be a constant change in properties with the development of negative charge over time and the change in surface properties and interactions with dissolved organic carbon and minerals. And the step from describing the basic biogeochemistry of biochar to a biochar system that can be applied under a range of situations is challenging. These challenges range from sustainable feedstock production for the generation of biochar through pyrolysis, the optional energy capture, the handling and management in soil.

02/12/09 - A chicken in every pot: Using computer models to understand the capacity of land to meet human food needs (Christian Peters, Post Doctoral Associate, Crop and Soil Sciences, Cornell University) Abstract: Land is a fundamental agricultural resource. In light of global population growth, trends toward more affluent diets, and environmental change, questions related to the land requirements of human food needs continue to be relevant. This talk will focus on the insights that modeling can provide, using examples from Dr. Peters research on New York State. In addition, the talk will address the future directions for such research in the context of the evolving debates on local food and bio-energy.

02/19/09 - Summary of phosphorus in streams, wells and lakes in central NY, 1972-2009 (David Bouldin, Emeritus Professor, Crop and Soil Sciences, Cornell University) Abstract: Peiodically, between 1972 and 2009, several thousand samples of streams and monitoring wells in central NY were analysed for one or more of the following 3 phosphorus fractions: molybdate reactive P (MRP,determined on centrifuged/filtered samples without further treatment); total dissolved P (TDP,determined on centrifuged filtered samples after oxidation with persulfate); and total P (TP, sum of TDP plus P on sediment). These fractions are comparable with corresponding three fractions for Cayuga Lake which have been reported for the Bell Station (1968-70) and Lake Source Cooling (1999-2008). These were combined with historical weather records and stream flow .from the North East Climate Center and USGS respectively. Based on about 750 MRP determinations over the 37 years in Fall Creek (near USGS Forest Home gauging station), the flow weighted concentration (FWC) was 18 PPB P ( ~6.0e-7 moles per liter of inorganic, orthophosphate P). TDP was 30 PPB and TP was ~ 2PPM. There were no important changes over this period. For comparison, in two streams draining subwatersheds without human activity, monitoring wells on the Harford T&R center and deep water from Cayuga Lake the concentration of MRP was about 40 % of the FWC In the period 1972-74, about 6000 kg of MRP was delivered to Cayuga Lake; about 2/3 was from human activities while the remainder was from land not actively used by humans. TDP was measured on 50 samples over 1.5 years from the several streams draining into the southern end of Cayuga Lake. The ratio of concentration of TDP relative to Fall Creek was about 1.2. Comparison of Fall Creek MRP with comparable P fraction from Cayuga Lake indicates about 50% of the MRP is lost in the lake. Consideration of inorganic chemistry supports the hypothesis that an important part of this loss is precipitated as calcium phosphates or co-precipitated with calcium carbonate. If true then this is a mechanism for essentially permanent inactivation of about half the inputs of MRP. References: In 1972 Cornell University formed a project with the title “Nitrogen and Phosphorus: Food production, Waste, the Environment”. Disciplines included Limnology, Agronomy, Agricultural Economics, Agricultural Engineering and Rural Sociology. In 1975 progress was summarized in the book: Porter, Keith ed 1975. Nitrogen and Phosphorus: Food production, Waste, the Environment. Ann Arbor Science Publishers. Ann Arbor MI Published and unpublished manuscripts and data can be found on the following web sites: http://hdl.handle.net/1813/2547; http://hdl.handle.net/1813/8146; http://hdl.handle.net/1813/8148 http://hdl.handle.net/1813/8351; http://hdl.handle.net/1813/8380

02/26/09 - The groundwater arsenic problem in Bangladesh: from earth science to mitigation? (Alexander van Geen, Senior Research Scientist, Lamont-Doherty Earth Observatory, Columbia University) Abstract: Dr. van Geen is Associate Director of a 5-year $16.9 million grant from the National Institute of Environmental Health Sciences (NIEHS) Superfund Basic Research Program to Columbia University for investigations into the health effects and geochemistry of arsenic and manganese in groundwater of New England and South Asia, especially Bangladesh. The seminar will provide I) background to the groundwater As contamination problem in Bangladesh, 2) some key results on human health and As mitigation, 3) a mechanistic discussion on the relationship between local recharge, soil permeability, and the accumulation of arsenic in shallow groundwater, and 4) some of the rice paddy observations made by the Columbia University group.

03/05/09 - Delivering a gigaton biochar carbon offset: The energy balance and economic opportunities for biochar in a trading scheme (John Gaunt, Adjunct Associate Professor, Crop and Soil Sciences, Cornell University) Abstract: Human induced carbon emissions are in the order 25 billion tons (gigatons-GT) carbon dioxide (CO2) annually. Current atmospheric CO2 levels are approximately 400 ppm or 3,200 GT CO2 (1 ppm CO2 equates to 8 GT CO2 in the atmosphere) exceeding what are generally regarded as safe limits by 400 GT. If we accept that levels of CO2 in excess of 400 ppm in the atmosphere pose a threat to our environment, then the dual challenges that face us are i) to remove CO2 from the atmosphere and stabilize it against re-release, and ii) to reduce the rate of release of CO2 to the atmosphere.  In both cases GT scale interventions are needed. The potential contribution of biochar produced by the thermal conversion of biomass by pyrolysis, combined with the production of bioenergy products is both regionally and globally significant at the GT scale. This presentation will examine contrasting configurations of pyrolysis and biochar and will consider implications of C emissions trading.

03/12/09 - Spatially and temporally explicit modeling of conditions for primary production of annuals in dry environments (Tal Svoray, Visiting Scientist, Ben-Gurion University of the Negev, Israel) Abstract: Studies report an enormous heterogeneity of vegetation production in different climatic regimes. Nevertheless, the ability to generalize these findings to unguaged regions remains a challenge. We developed a fuzzy-rule-based heuristic model that predicts daily conditions for germination and production of annuals in heterogeneous environments, at the landscape scale. The model will be presented and its use to study vegetation response to interannual variations, to climate change scenarios and to the effect of grazers.

03/19/09 - NO SEMINAR - SPRING BREAK

03/26/09 - Streamwater nutrient and carbon losses from agricultural headwater catchments for a gradient of soil organic matter degradation (John Recha, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: Farming after land conversion from primary forest has resulted in decline in soil organic matter and nutrients in western Kenya. In order to allow up-scaling of these results, experiments have been established with the main objective to investigate how nutrient and carbon losses from agricultural watersheds are controlled by the state of degradation of soils in headwater catchments. The agricultural watersheds were selected based on different lengths of growth of crops after land conversion from primary forest. This will allow assessment of flow paths and develop knowledge to curb the nutrient losses for higher crop production.
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Insights on changes in weed vigor and growth in response to varying soil nitrogen fertility (Stephanie Whitehouse, Graduate Student, Crop and Soil Sciences, Cornell University) Abstract: Macronutrients such as nitrogen may be key drivers of weed-crop competitive outcomes. Large supplies of nitrogen made available early in the growing season may increase the competitive ability of weeds relative to crops. Numerous studies have shown changes in weed growth and vigor at different nitrogen rates; however the effects of varying nitrogen availability as a means of weed control remain unclear. The research reported here comprises two studies investigating the effects of different nitrogen application rates on weed growth and vigor under field and greenhouse conditions. The use of nitrogen management as a method of weed control in cropping systems will be discussed based upon findings from this work.

04/02/09 - Crop rotation planning on diversified farms: living in the real world (Chuck Mohler, Senior Extension Associate, Crop and Soil Sciences, Cornell University) Abstract: Implementing a good crop rotation on a farm growing a diversity of crops is remarkably difficult. Great variation in acreage among crops, multiple cropping, variation in field conditions and other factors makes a simple repeating sequence of crops impractical. The Northeast Organic Network (NEON) crop rotation initiative used intensive consultation with experienced growers and extensive literature review to develop a series of tools to help growers manage crop rotations. These include a grower consensus report on planning strategies, many examples of crop sequences used on real farms, summaries by scientists on the use of crop rotation for managing soil and pests, an Excel based procedure for making a rotation planning map, a step-by-step rotation planning procedure, a chart showing the problems and opportunities associated with over 1,300 crop sequences, and extensive tables showing characteristics of crops, weeds and crop pathogens relevant to crop rotation planning, These materials will be available in a book "Crop Rotation on Organic Farms: A Planning Manual" that will be published summer, 2009.

04/09/09 - Generating biological data on two invasive swallow-wort species (/Vincetoxicum /spp.) to better inform their management using biocontrol (Kristine Averill, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Pale and black swallow-wort (Vincetoxicum rossicum and V. nigrum, respectively) are nonnative, perennial, herbaceous vines in the Apocynaceae. The species are becoming increasingly problematic in the northeastern United States and southeastern Canada and management of the species has been challenging. Consequently, a classical biological control program was initiated in 2004 by the USDA-ARS with the goal of providing sustainable and economical long-term suppression of these two invasive species. Success of this biological control effort depends on the availability of plant demographic data, which can be modeled to determine which swallow-wort life stage(s) are likely to be most susceptible to control efforts. I will present results from my field research, including swallow-wort establishment success, vegetative expansion, fecundity, and survival and will discuss how these data better inform biocontrol practitioners seeking to manage these species.
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Near-infrared diffuse-reflectance spectroscopy and geospatial landscape information: An integrated approach to digital and predictive soil mapping (EJ Neafsey, Graduate Student, Crop and Soil Sciences, Cornell University) Abstract: Proximal sensing using diffuse-reflectance near-infrared spectroscopy has demonstrated substantial potential in the rapid, accurate estimation of key soil properties. Many of these soil properties are diagnostic for the purpose of soil classification and survey. Digital and predictive soil mapping (DSM and PSM, respectively) also have been employed to estimate critical soil properties and to complement current methodologies employed in the soil survey update process. This study will be guided by the following objectives: (1) assess the potential of integrating diffuse-reflectance near-infrared spectroscopy (DRS NIR) spectra with PSM to enhance prediction of properties critical to soil survey, create soil pedon visualization products and suitability maps for DRS NIR; (2) develop a comprehensive DRS NIR spectral library and robust prediction models for some of Connecticuts benchmark soils and archived soil survey samples; (3) support subaqueous soil mapping efforts in southern New England estuaries and selected salt ponds in Rhode Island; (4) determine the utility of using DRS NIR for measuring sulfidic soil properties, and (5) support NCSS soil survey programs in southern New England.

04/16/09 - Cassava drought tolerance mechanisms re-visited: Evaluation of drought tolerance contrasting cassava varieties under water stressed environments (Luis Duque, PhD Candidate, 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.

04/23/09 - Field-Scale Corn Research on New York Farms (Bill Cox, Professor, Crop and Soil Sciences, Cornell University) Abstract: Increasing numbers of dairies in NY are classified as confined animal feeding operations (CAFOs). Many dairy farmers abandoned conventional and adopted zone tillage (ZT) in 4-yr corn (Zea mays L.) silage-alfalfa (Medicago sativa L.) rotations on highly erodible land to comply with NY CAFO plans. We conducted a 2-yr field-scale study at Table Rock Farm in western NY to determine optimum ZT depth for corn silage in continuous corn and first-yr corn following alfalfa. The ZT depth (with attached Aerway implement), evaluated at 0, 18, and 36 cm, did not affect surface residue (~34%), plant densities (71 605-73 998 plants ha-1), and dry matter (DM) accumulation at the 12th leaf stage (334-365 g m-2). Significant contrasts were observed between 18 vs. 0 cm for DM yield (19.9 and 18.7 Mg ha-1) and N uptake (236 and 219 kg ha-1, respectively), but not between 18 vs. 36 cm (19.7 Mg ha-1 and 237 kg ha-1).The ZT depth did not affect silage quality. Partial budget analyses indicate that reducing ZT depth from 36 to 18 cm increases profit by ~$30 ha-1 because of decreased labor ($1.48 ha-1), fuel ($5.88 ha-1), and equipment repair and maintenance costs ($3.01 ha-1) and increased return from higher yield ($21.98 ha-1, offset by $2.57 ha-1 increased harvest cost). Farmers should experiment with reducing ZT depth to 18 cm for corn silage production on silt loam soils in NY. Transgenic corn hybrids (glyphosate-resistant and Bt hybrids for European corn borer and/or corn rootworm control) occupy more than 60% of the corn acreage in the USA and will probably increase in the near-future. In NY, however, European corn borer is an occasional pest and variants of western corn rootworm generally don’t result in as severe damage as in the Midwest USA so adoption of this technology may not always be justified. We evaluated the base genetics of two hybrids vs. their double (glyphosate-resistant and Bt- European corn borer), and triple (glyphosate-resistant, Bt-European corn borer, and Bt-corn rootworm)-stacked counterparts in field-scale studies on four farms in NY in a corn-corn rotation and the base genetics vs. double-stacked counterparts in a corn-soybean rotation to evaluate the agronomics and economics of the hybrid traits. When averaged across 2 years, two hybrids, and four locations, double and triple-stacked hybrids yielded 2.6% higher than the base genetics in the corn-corn rotation and double-stacked hybrids yielded 2% higher in the corn-soybean rotation. Less lodging occurred in the transgenic hybrids but the transgenic hybrids averaged about 1.5% greater grain moisture at harvest, which could lead to increased drying costs. Results from this study indicate that Bt hybrids protect yield when insect pests occur but do not enhance yield in the absence of pests.

04/30/09 - Thermal analysis techniques for assessing soil organic matter quality (Alain Plante, Assistant Professor, Earth and Environmental Science, University of Pennsylvania) Abstract: Soil organic matter (SOM) consists of a “quality continuum” ranging from highly labile compounds with turnover times of days to months, to humified materials and charcoals that may persist for centuries or millennia. This research seeks to achieve a meaningful quantification of this quality continuum through the application of thermal analysis techniques. The potential for the application of thermal analysis technology is the state-of-the-art development of a relatively rapid, inexpensive, information-rich fingerprint for the relative stability of SOM, which could be used as a tool in soil quality assessments.

05/07/09 - Mapping connections between the genome, ionome and the physical landscape (David Salt, Professor, Horticulture and Landscape Architecture, Purdue University) Abstract: Understanding how organisms control their ionome or mineral nutrient and trace element composition, could have a significant impact on both plant and human health. Furthermore, associating the genetic determinants that underlie natural ionomic variation, with the landscape of the individuals that carry these genotypes, will provide insight into the genetic basis of adaptation and speciation. We have employed high-throughput mineral nutrient and trace element profiling, using inductively coupled plasma – mass spectrometry (ICP-MS), as a tool to determine the biological significance of connections between an organism’s genome and its ionome. Our focus is on genes that control uptake and accumulation of mineral elements, including Ca, K, Mg, P (macronutrients in plant fertilizer), Co, Cu, Fe, Li, Mn, Mo, Ni, Se, Zn, (micronutrients of significance to plant and human health) and As, Cd, Na and Pb (elements causing agricultural or environmental problems). To date we have analyzed the ionome of over 100,000 Arabidopsis plants and 20,000 yeast samples. This includes several Arabidopsis forward genetic screens (Lahner et al., 2003 Nat. Biotechnol. 21:1215), a screen of 360 natural Arabidopsis accession, and a complete analysis of all 5153 strains of the yeast deletion collection (Danku et al., 2009 JAAS (in press)). We have successfully used PCR-based positional cloning, DNA microarray based approaches, QTL and association mapping to identify numerous genes that control the ionome (for example Rus et al., 2006 PLoS Genetics 2(12): e210; Baxter et al., 2008 PLoS Genetics 4(2):e1000004). Association of variation in these genes with the landscape in which these plants naturally grow is starting to reveal the genetic architecture underlying specific adaptations to the environment. We are also finding that specific ionomic “fingerprints” are associated with functionally related sets of genes, and also with the physiological status of the organism (Baxter et al., 2008 PNAS 105: 12081-12086). To maximize the value of this ionomics approach, we have developed a publicly searchable online database containing ionomic information on over 1000,000 samples from over 1500 different experiments (www.ionomicshub.org; Baxter et al., 2007 Plant Physiol 143: 600-611), and the database is being updated regularly.

FALL 2008

08/28/08 - Soil health management and regional organics cycling in Western Australia (Dr Bob Paulin, Department of Agriculture and Food, Western Australia) Abstract:  Dr. Paulin will discuss research outcomes related to soil health management, and vegetable grower development of improved soil management practices. In addition, he will describe new policy initiatives related to City to Soil organic recycling programs and considerations of land use planning through establishment of greenbelt regions with intensive agricultural capability.

09/04/08 - Using demographic models to guide biocontrol of invasive plant species (Adam Davis, Professor/Ecologist, USDA-ARS Invasive Weed Management Unit, Urbana IL) Abstract: Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) (Brassicaceae) and pale and black swallow-wort (Vincetoxicum rossicum (Kleopow) Barbar. and V. nigrum (L.) Moench) (Apocynaceae) are widespread invasive plants considered to be among the most harmful exotic plant invaders in North America. Extensive work on conventional controls have failed to yield practical methods for large-scale suppression of these species, and biological control is viewed by many as the only effective means to manage these plants on landscape scales. However, there is increasing awareness of the non-target impacts of some weed biological control efforts. While recognizing the importance of biocontrol, there has been a call to increase the rigor of these programs and to assure that biocontrol agent guilds have strong impacts on target plants. The challenge for invasive plant biologists is to predict if the likely impacts of a single biocontrol agent or guild of agents are sufficient to result in adequate target suppression across a range of habitats and geographic areas and thus, to justify the risks of an introduction. Co-sponsored by the USDA-ARS Biological Integrated Pest Management Research Unit

09/11/08 - Summary of nitrate N in Fall Creek, 1972 - 2008 (David Bouldin, Emeritus Professor, Crop and Soil Sciences, Cornell University) Abstract: Between June 1972 and March 2008, over 1500 water samples from Fall Creek in central NY were analyzed for NO3-N. This data was combined with USGS flow data and Ithaca weather data to yield the following conclusions: Average loading was 6.3 kg NO3-N per hectare per year (=5.5 pounds/acre/year) and average flow weighted concentration was 1.18 milligram per liter (=85micromoles NO3-N/liter). The variation of yearly loading and flow weighted concentration was related to climatic variation. Variation in human activity over 36 years appears to be unimportant. The best variable for interpolation of NO3 between sampling intervals was average temperature for the previous 5 days. The most important conclusion is that the numerous aquifers, the soil organic matter and the mosaic of human activities buffer the concentration and loading of NO3 so that changes in the output of the whole water shed will only occur over periods of decades. However, among the sub-watersheds and specific aquifers there are large differences in concentration but limited long term data on changes in the recent past; more attention should be given to those which are important sources of potable water. Another important observation is that concentration of NO3 in summer is about 1/10 of the winter concentrations and thus any useful sampling regime MUST include samples during all seasons.

09/18/08 - Competition for above and below ground resources among annual species from the plant to the field: quantification, analysis and modeling (Andres Berger, PhD Candidate, Earth and Atmospheric Sciences, Cornell University) Abstract: Competition for resources is common in both mono-species (crop) and multi-species (crop-weed) systems. There is still an important lack of knowledge and understanding of the mechanisms involved in competition for resources and particularly on how these mechanisms may interact. Furthermore, crop-weed competition is a dynamic process that depends on changing weather and soil conditions, as well as on plant community factors, such as density and spatial arrangement. Mechanistic crop-weed simulation models offer a computational approach for dynamically exploring interactions among the diverse drivers of competition. In this seminar I will present results from field experiments conducted to analyze patterns of soil water acquisition, total water use and water use efficiency by weedy and weed free corn, and parameterize a spatially explicit individual based model of crop-weed competition. I will also present the main features of the model developed along with results and insights obtained from the time series simulation of several scenarios of soil nitrogen availability, spatial arrangement, and competitive ability of plants.

09/25/08 - Fate of black carbon two years after addition to a tropical savanna Oxisol, and implications for soil carbon sequestration management (Julie Major, PhD Candidate, Crop and Soil Sciences, Cornell University) Abstract: Black carbon (BC) is an important C pool globally, and it cycles at a much slower rate than non-BC mainly due to its high content of aromatic, graphitic, or elemental refractory C. Managing BC for actively increasing the long-term C sink of atmospheric carbon dioxide in the form of BC from biochar in soil has been proposed, and relies on accurate information about its stability. This work was undertaken to assess the fate of biomass-derived BC after addition to surface soil in the field over two years. After applying BC to a Colombian savanna Oxisol, we measured leaching by saturated flow at 0.15 and 0.3 m, soil respiration and took soil samples. Field work was carried out in this region because it permits the use of stable C isotopes to attribute sample C to applied BC or to "resident" organic matter. The fate of applied BC and "resident" C, as it leached in particulate and dissolved forms and was respired will be presented, along with data on changes in soil C stocks and plant productivity on the site. Implications for C sequestration by BC application to soil will be discussed.

10/02/08 - Biochar for carbon sequestration; the potential for biochar production and feedstocks in the UK (Mariska Evelein Msc, Exchange Visitor, Crop and Soil Sciences, Cornell University) Abstract: In the view of climate change mitigation, the UK has set itself stringent targets for carbon reduction, as well as waste elimination. This research looked in broad terms at the feedstocks that could be made available for biochar production from waste and forestry in the UK, and how much carbon this could stabilise in biochar.

10/09/08 - NO SEMINAR

10/16/08 - Digital soil mapping: Update from the North American Node of GlobalSoilMap.net (Steve DeGloria, Professor, Crop and Soil Sciences, Cornell University) Abstract: A consortium of pedologists has formulated a global soil mapping initiative consisting of six continental nodes to support the goal of mapping selected soil properties over 80% of the Earths land surface (GlobalSoilMap.net). Soil survey organizations in Canada and the United States have initiated a collaborative case study to test the feasibility of this effort for the North American continent. Specific objectives of this case study are to map selected soil properties based on detailed (1:12,000-1:40,000) and generalized (1:250,000-1:1,000,000) soil survey information using environmental covariate data and digital soil mapping methods with comparison of soil property maps developed from these two mapping approaches. We also seek to advance international exchange and quality assessment of soil survey data and information that will improve management of agricultural and natural resources, especially those that transcend national boundaries. To date, we have assembled a team of soil scientists from Agriculture and Agri-Food Canada, USDA-NRCS and several universities to establish project objectives, assemble spatial data, develop a work plan, implement appropriate DSM methods, and evaluate mapping outcomes for addressing local and transnational resource management needs.

10/23/08 - Grasping at Proteus: Making sense of microbial diversity (Dan Buckley, Assistant Professor, Crop and Soil Sciences, Cornell University) Abstract: Proteus, son of Poseidon, prophesied of all things past, present, and future. He shared this knowledge only with those who could grasp and hold him, a task of heroic proportion since Proteus, when seized, would rapidly change his shape to avoid capture. Our knowledge of microbial diversity is limited by protean aspects of its nature, every time we feel like we are getting a hold on microbial diversity, new discoveries change the way we view the problem. In this seminar we will explore our current understanding of soil microbial diversity and see how reductionist approaches can be used to provide insights on linkages between microbial diversity, soil characteristics, and soil processes. Our primary focus will be on the use of free-living nitrogen fixing bacteria as a model system to demonstrate the functional significance of microbial diversity in soils, but we will also discuss the potential for genome ecology to provide insights on the ecological and evolutionary forces that govern the structure of microbial communities in soils.

10/30/08 - Factory Farms versus Alternative Animal Agriculture (Moderated by Ellen Harrison, Former Director, Cornell Waste Management Institute, Cornell University) Abstract: What are the pros and cons of industrial agricultural production vs. small local livestock farms in terms of sustainability, animal welfare and human health? The “buy local” movement would suggest that the answer is obvious, but the speakers will challenge us to consider these questions in a more nuanced way. Participants: Main Speaker on Animal Welfare: Temple Grandin, Professor of Animal Science at Colorado State University and Supplemental Speaker on Sustainability and Health: Joe Regenstein, Professor of Food Science at Cornell. Reactor panel: Peter McDonald of McDonald Farm Pasture Pride Meats in Romulus, NY (www.pasturepride.com) and tatiana Stanton Goat Extensionist for NYS and goat farmer (www.sheepgoatmarketing.info) (Note time change: 12:20-1:30 pm)

11/06/08 - Large Scale Dairy Manure Vermicomposting in NY State: Horticultural applications and impacts on plant-associated microbial communities (Thomas Herlihy, PE Executive Director, RT Solutions LLC; Allison L H Jack, MS, Department of Plant Pathology and Plant-Microbe Biology, Cornell University) Abstract: Western NY is now the North American center of large-scale vermicomposting thanks to a pilot facility built in Avon, NY in 2005. The unique design of this facility allows for the rapid (75 d) processing of separated dairy manure solids into a high value horticultural product worth up to 20 times thermophilic windrow compost, providing an economic incentive to move excess manure out of nutrient-saturated watersheds. The system includes a forced air thermophilic composting phase and highly automated continuous flow through earthworm beds. Results of past and ongoing research projects with several departments at Cornell will be discussed. We've investigated horticultural applications of vermicompost including amendment to soil and transplant media for a variety of vegetable crops, as well as the effect of amendment on plant associated microbial communities. As a transplant media amendment, vermicompost impacts rhizosphere bacterial communities while the seedling is in the transplant plug and for up to 2 months after transplanting into field soil. Vermicompost amendments can also suppress seedling damping off caused by Pythium aphanidermatum in cucumber. Preliminary results suggest seed-colonizing microbial communities impact zoospore pre-infection behavior.

11/13/08 - Agroecosystem management and nitrogen mass balance in the Midwestern United States (Jennifer Gardner, PhD Student, Crop and Soil Sciences, Cornell University) Abstract: Nitrogen (N) leaching to surface waters from grain farms in the Mississippi River Basin (MRB) is the primary cause of the hypoxic zone in the Gulf of Mexico. This research is part of an interdisciplinary project exploring interactions between social and ecological processes in agricultural landscapes in the MRB using Gulf hypoxia as a model system. We are testing the biophysical hypothesis that agronomic management practices which re-couple the biogeochemical cycles of carbon (C) and N reduce potential N loss from grain fields. We are constructing field-scale N mass balances for nearly 100 working farms in the MRB to measure the largest, most important N flows regulated by farm managers. The management gradient spans continuous corn and corn-soybean rotations, rotations with winter annuals, use of annual and perennial legume N sources, diversified organic grain farms, and perennial rotational grazing systems. Potential N loss will be assessed using calculated N surplus and environmental data (e.g., soil type, tile drainage, and slope) from each farm. We will share preliminary data and discuss the most uncertain N balance terms, as well as plans for future corn grain and legume biomass sampling and mechanistic work to improve and complement the mass balances.

11/20/08 - The influence of winter field cover on spring nitrous oxide emissions (Ranae Dietzel, MS Candidate, Crop and Soil Sciences, Cornell University) Abstract: Agriculture is responsible for 60% of anthropogenic emissions of nitrous oxide (N2O), a harmful agent of climate change. A majority of this N2O is emitted during spring soil thawing. In this study, I examined the influence of two winter field covers, snow and winter rye, on soil temperatures and subsequent spring N2O emissions in a NY field. Field measurements were followed by a soil freeze-thaw simulation that focused on the effect of slower thaw rates on N2O fluxes and tracked changes in N2O / N2 ratios during thawing. The occurrence of a freeze-thaw cycle, the absence of field cover, and slower thawing rates led to increases in N2O fluxes. N2O / N2 ratios exhibited dramatic and unexpected behavior during soil thawing. These results have climate change implications and provide a basis for field management recommendations.
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Yield of corn strip-cropped with soybean under variable population and nitrogen rates (Clay Mitchell, MS/PhD Student, Crop and Soil Sciences, Cornell University) Abstract Mitchell: Increased nitrogen costs require agronomic practices that increase corn (Zea mays L.)  yields without losing the benefits of rotation.  Recent availability of corn and soybean [Glycine max (L.) Merr.] sharing the same herbicide tolerance, and automated navigation systems for agricultural machines with sub-inch accuracy make strip intercropping the two species a costless alternative to monocropping for large-scale farms possessing these technologies.  Objectives of this research were to determine the effects of strip intercropping on corn yields, and to identify interactions with row position, plant populations, and  nitrogen rates.  Treatments consisted of row position, three plant populations (58 000, 80 000, and 108 000 seeds ha-1), and four N rates applied at four row positions within the corn strips (0, 90, 130, and 160 kg N ha-1).  Population was randomly assigned to 260 m subplots within each of the four strips.  Nitrogen rate was randomly assigned within each subplot to subunits consisting of a set of 3 adjacent rows. 

11/27/08 - NO SEMINAR - THANKSGIVING RECESS

12/04/08 - NO SEMINAR

12/11/08 - Anthropogenic biomes, soil quality and global food security (Ademola Braimoh, Professor, Center for Sustainability Science, Hokkaido University and Executive Director of the Global Land Project, Sapporo Nodal Office, Japan) Abstract: Two global datasets important to Land Change Science were used to study the incidence of food insecurity across world regions. Datasets used for this study included the map of anthropogenic biomes that reflects the direct human interaction on ecosystems, and the map of inherent land quality which shows the resilience of soils based on pedoclimate information. The proportion of human-impacted landscape ranges from 56% for North Africa and Near East to about 95% for Asia and the Pacific, whereas the proportion of easily degraded lands and those uneconomical for crop production ranges from 25% for Latin America and the Caribbean to 87% for North Africa and the Near East. Analyses reveal a strong competition between croplands and urban areas for prime soils. There exist relationships between the proportion of “agricultural” biomes and proportion of lands with moderate suitability for crop production; the proportion of undernourished population and the proportion of agricultural biomes; and the proportion of undernourished population and arable lands. Incorporation of socioeconomic variables in the analyses led to the identification of research and policy needs to improve food security for different regions of the world.

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Biogeochemistry and Environmental Change
Natural Resources
Plant Breeding

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