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Comparison of nitrogen and phosphorus from two drainage water management systems on agricultural organic soils
Friday, September 11, 2020, 10:00 am PDT / 1:00 pm EDT
Presenter: Genevieve Grenon
Autors: Genevieve Grenon,* Chandra A. Madramootoo, Bhesram Singh, and Christian von Sperber
Affiliation: Department of Bioresource Engineering, Macdonald Campus of McGill University, 21111 Lakeshore Rd, Ste. Anne de Bellevue, Québec, Canada H9X 3V9; C. von Sperber, Department of Geography, McGill University
Nutrient released into the environment from agricultural tile drainage is a major contributor to increased eutrophication in waterbodies. Mitigation practices to reduce nitrogen and phosphorus loss, include drainage water management (DWM). This study assessed two DWM systems: a control drainage structure (CD) located on the subsurface tile outlet before discharge, and a farmer’s management system using a pump (PD) that discharged when the farmer deemed it necessary. These two DWM techniques were evaluated in 2015 and 2016 in terms of their efficacy to reduce nutrient outflows from subsurface tile drainage. The results identified PD as significantly correlated to the drain discharge, denoting that the water movement within the field occurs at similar time periods as discharge. The N loads were found to be lower under PD (2 – 21 kg ha-1) allowing for increased N retention in the field when compared to CD (35 – 53 kg ha-1). The N loads were significantly different (p < 0.05) between the two sites, while the P loads were not significantly different in 2015. In 2015, the discharge under PD was less than CD, although PD had an increase in P loads (PD 0.90 kg ha-1; CD 0.60 kg ha-1). In 2016, the P loads were less per volume under CD when compared to PD. Overall, PD was more effective in managing N loads, while the CD system was more efficient in reducing P loads.
Select soil quality and plant uptake parameters under different water and fertilizer management systems and their relationship with greenhouse gas emissions
Friday, September 11, 2020, 10:20 am PDT / 1:20 pm EDT
Presenter: Naeem A. Abbasi
Authors: 1 Naeem A. Abbasi, 1 Chandra A. Madramootoo, 2 Tiequan Zhang, 2 Chin S. Tan
1 Department of Bioresource Engineering, McGill University, Sainte-Anne-de-Bellevue, Quebec H9X 3V9, Canada
2 Harrow Research and Development Center, Agriculture and Agri-Food Canada, Harrow, Ontario N0R 1G0, Canada
Agricultural fertilizer and water management practices have short- and long-term effects on soil chemical and physical properties and, in turn, greenhouse gas (GHG) emissions. A 4-year study (2012-15) was conducted to assess the effects of different fertilizer and water table management practices on soil carbon (C), nitrogen (N), plant N uptake parameters and their relationship to GHGs emissions [carbon dioxide (CO2) and nitrous oxide (N2O)], in a corn-soybean rotation. Inorganic fertilizer (IF) and a mix of solid cattle manure and inorganic fertilizer (SCM) were two fertilizer treatments combined with tile drainage (DR) and controlled drainage with sub-irrigation (CDS). Soil C and N parameters were assessed in the spring season each year. N in biomass (BMN) and N in grain (GRN) were measured and used to calculate other plant N parameters at harvest. The N2O and CO2 fluxes were collected weekly, and their respective cumulative emissions were calculated during the four growing seasons (2012-15). The results showed that soil C, total N and soil organic matter (OM) were 35%, 33% and 32%, respectively, greater in SCM than IF in the top 15 cm soil depth. Furthermore, CO2 emissions were 30% greater, and N2O emissions were 25% lower from SCM compared to IF. Soil total N and total C were positively correlated with CO2 emissions, indicating the importance of N availability on soil respiration. Plant N uptake parameters were negatively correlated with N2O and CO2 emissions, suggesting that agricultural practices with higher plant N uptake can reduce N2O and CO2 emissions.
An Experimental Study of the Aerodynamic Characteristics of Ryegrass Forage
Friday, September 11, 2020, 10:40 am PDT / 1:40 pm EDT
Presenter: Janaya Walter
Authors: 1Janaya Walter, 1Martin Roberge, 2Laurent Schindfessel, 3David Sumner, 1Lope Tabil
1 Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan,Canada
2 Civil Engineering, Ghent University, Ghent, Belgium
3 Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
During harvest, a self-propelled forage harvester (SPFH) is used to collect, chop, and transport grasses and corn varieties by means of airflow to an external collection unit. The transportation system can sometimes become blocked and fail to provide an acceptable throughput, largely caused by poor crop and environmental conditions. For this reason, it is critical to understand the behavior of the airborne crop material for a variety crop conditions which aerodynamics play a key role in. This study focuses on developing a correlation between the drag and lift coefficients of the material and its physical characteristics to contribute to the design process of the transport system. More specifically, non-spherical particles are of considerable interest, and in agricultural engineering, the material’s moisture content is a significant factor. Measurement techniques and methodology are also discussed. An experimental procedure was developed to measure the mass distribution of ryegrass samples when injected into a horizontal wind tunnel. From these tests, both aerodynamic coefficients were determined as functions of the average particle length and the sample’s moisture content. Subsequently, a second set of experimental tests were performed in a vertical wind tunnel to calculate the drag coefficient from the material’s terminal velocity. The results from the vertical wind tunnel are used to validate the corresponding tests in the horizontal wind tunnel.