North American Agroforestry Conference - Papers
Permanent URI for this collection
Browse
Recent Submissions
Item Carbon sequestration potential of a 27-year-old tree-based intercropping system in southwestern Ontario(2013) Wotherspoon, Amy; Mohammed, Idris; Thevathasan, Naresh V.; Gordon, Andrew M.; Voroney, R. Paul; North American Agroforestry Conference (13th : 2013 : Charlottetown, Prince Edward Island, Canada)This study aimed to quantify carbon (C) pools and fluxes in a 27-year-old tree-based intercropping (TBI) system as compared to a conventional agricultural system at the University of Guelph�s Agroforestry Research Station (43o 16�N 89o 26�W) (established 1987). Tree species quantified during this study include poplar hybrid (Populus spp.), Norway spruce (Picea abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis). In the TBI system, above- and belowground biomass, along with soil organic carbon (SOC) concentrations, litterfall, litter decomposition and soil respiration were quantified. In the conventional agricultural field, SOC, litter decomposition and soil respiration were quantified. Preliminary results indicated higher C sequestration potential rate with faster growing species such as poplar, and slower potential rate for slower growing species such as spruce and cedar. SOC accumulation was highest in the predominant wind direction (east), closest to the tree rows (0.5 m), and at shallower depths (10-20 cm) for all species. SOC accumulation was highest under poplar tree, followed by spruce, oak and walnut. Quantities of litterfall followed similar pattern and decomposition rates are still being analyzed. Soil respiration rates were higher in TBI systems and at distances closer to the tree row. Further results will be presented on the total measured C pools and fluxes and the importance of C sequestration potential of a 27-year-old TBI system to sequester atmospheric C and mitigate climate change. Accumulation of SOC can also have implications on crop yields and long term stability of TBI soils.Item An international success : Great Plains Windbreak Renovation & Innovation Conference, 2012(2013) Straight, Richard; Kort, John; Stange, Craig; North American Agroforestry Conference (13th : 2013 : Charlottetown, Prince Edward Island, Canada)In March of 2011 discussions began among conservation agencies and organizations in Canada and the U.S. about the need for a region-wide conference or training session on windbreak renovation. Representatives from three Provinces, eight States, numerous local agencies and two federal agroforestry centers met to plan such a conference. That was the beginning of the Great Plains Windbreak Renovation and Innovation Conference that was held in July of 2012 at the International Peace Garden on the border of the U.S. and Canada. The end result after a year of planning was a conference attended by 82 people in-person from 11 states and 3 provinces and about 35 people remotely via the internet. The key components of the planning process that led to a successful conference included: region-wide representation from local, provincial, state and federal conservation partners; a survey of agencies on the likelihood of the number of people they would support to participate in the conference; and a commitment to create learning opportunities apart from the primary conference site. Participant evaluations of the conference indicated that the mix of science, real-world experiences and new techniques and equipment helped make the conference a success. Results from the initial Great Plains conference include: Provincial windbreak renovation meetings, a Southern Great Plains Windbreak Renovation Conference and an online lecture series utilizing ten speakers from the original conference.Item Verification of shelterbelt crop yield improvements in the Great Plains region(2013) Stange, Craig; Brandle, James; Nowatzki, John; Wyatt, Gary; Stoner, Ray; North American Agroforestry Conference (13th : 2013 : Charlottetown, Prince Edward Island, Canada)In 1962, J. H. Stoeckeler summarized the impacts of windbreaks on agriculture in the Great Plains. This paper has been the standard by which windbreak benefits, particular crop yield benefits have been judge. Over the last 60 years, agricultural practices have changed dramatically. The use of minimum tillage and no-tillage practices has provided significant benefits in the control of wind erosion. Progress in hybrid genetics and the introduction of GMO crops have increased yields dramatically over the last 30 years. Many producers are asking if the benefits of field windbreaks are still economically viable. Can we still afford to divert land from production to field windbreaks? The availability of yield monitors, GPS systems and excellent satellite imagery may provide the technology to verify that the yield responses seen as a result of field windbreaks are still relevant today. Preliminary data will be collected during the summer of 2013 in at least five Great Plains States. Data protocols will be tested and refined during the late summer and funding sought in the fall. Our purpose in coming to the AFTA meeting is to seek additional input and suggestions from agroforestry professionals.Item APEX simulation : environmental benefits of agroforestry buffers on corn-soybean watersheds(2013) Senaviratne, Anomaa; Udawatta, Ranjith P.; Baffaut, Claire; Anderson, Stephen H.; Jose, Shibu; North American Agroforestry Conference (13th : 2013 : Charlottetown, Prince Edward Island, Canada)The Agricultural Policy Environmental Extender (APEX) model has the ability to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. The objectives of this study were to calibrate and validate the APEX model for three adjacent watersheds and determine optimum buffer dimensions and placement locations. ArcAPEX and APEX0604 versions were used for the simulations. The simulated corn and soybean yields were within 13% and 27% of the measured yields, respectively. The agroforestry, grass buffer, and control watershed models were calibrated (1998 to 2001) and validated (2002 to 2008) for eventbased runoff with r2 and Nash-Sutcliffe Coefficients (NSC) values of 0.7-0.8 and 0.4-0.8, respectively. The models could not be calibrated for sediment losses. The simulated grass and agroforestry buffers reduced average annual runoff by 5.2% and 4.3%, respectively. Increase of buffer widths to 5.5 m and 7.5 m were not effective. The buffers located on the backslopes were the most effective for the agroforestry watershed but this trend was not seen in the grass buffer watershed. The study provides guidance on how to parameterize APEX to simulate grass and agroforestry buffers. It contributes to the validation of APEX and will be useful to scientists in need of parameterizing the model for watersheds that include upland buffers.Item Evaluation of hybrid poplar clones under intensive cultivation for biomass production in Qu�bec(2013) P�rinet, Pierre; Th�riault, Ursule; Tremblay, Francois; North American Agroforestry Conference (13th : 2013 : Charlottetown, Prince Edward Island, Canada)Three experimental plantations were established in 2012 at three sites in the Bas-Saint-Laurent and Lac-Saint-Jean regions to promote and demonstrate the short-rotation-intensive-culture (SRIC) hybrid poplar crop concept for biomass production. The general objective of this study was to evaluate already-available material for poplar plantations and new hybrid poplar clones, obtained from breeding at the Direction de la recherche forestire, for SRIC. Many performing clones from different hybrids with Populus maximowiczii, P. nigra, P. trichocarpa, P. deltoides (MxN, MxT, MxD, etc.) are already available for evaluation of their characteristics under various coppicing regimes. The plantations were established in collaboration with regional organizations involved in energy crops like Osons l'Osier and Nutrinor to compare coppicing ability and biomass yield among poplar clones. Preliminary growth results obtained after the first growing season are presented for several clones. Significant clone differences are expected in vigour, yield, and coppice regrowth after repeated rotations. Mechanical harvesting of the crop may also have a strong influence on resprouting and sustainability of the stools over repeated growth cycles.