ABSTRACTS

Authors will be available between 4:30  and 5:30 PM on February 8th to discuss their research and findings.

Applying Precision Seeding Rates in Organic Dryland Grain Production

Sasha Loewen and Bruce Maxwell, Montana State University

Applying precision agriculture tools on field scale experiments has allowed for the development of on field precision experimentation (OFPE), which offers farmers and researchers new insights into the temporal and spatial variability of their land using modern precision agriculture technologies. OFPE is a methodology of farmer driven field scale experiments analyzed by scientist partners now, but with the vision to automate the analysis and recommendations for management. OFPE can be applied in any farm setting to learn about the variation within a specific field, relative to a specific input. The aspirations of OFPE are to increase farmer efficiencies, reduce inputs, and maximize producer profits through open source software applications. We demonstrated OFPE to organic producers by testing seeding rates of green manure cover crops and following year wheat (cash) crops using variable rate seeding equipment. In 2019 we planted (60kg/ha, 90kg/ha and 120kg/ha) peas on a field in Montana, USA that will get planted to three seeding rates of wheat in 2020. In the same growing season we applied three seeding rates (150 kg/ha, 180 kg/ha, and 225 kg/ha) of spring wheat and looked for yield differences across a 175 acre organically managed field in south east Manitoba. The high seeding rate produced the greatest yields, except on hilltops where the lowest seeding rate produced highest yields. Based on these results a model was constructed to optimize seeding rates across this field in the future. The net return on the wheat (based on 2013-2019 average organic wheat price) was $140.86/ha (USD). If the farmer had applied the mid-level seeding rate across the entire field they would have received $143.45/ha, and if they had applied the optimized variable rate described by the model, their net return would have been $149.58/ha. Early OFPE results indicate that optimized variable seeding rates outcompete farmer-chosen single field rates. Annual use of OFPE on a field will allow for continual optimization of that field over both time and space recognizing that performance will change over time and allow for quantification of uncertainty associated with recommendations. OFPE projects are underway on five organic grain farms in Montana and Manitoba. Continued experiments will test the efficacy on cash crops and nitrogen fixing cover crops, to optimize nitrogen levels in the soil, reduce weed pressure, and maximize producer net returns.

Struvite: A potential phosphorus source for organic crops

 

Joanne R. Thiessen Martens, Francis Zvomuya and Martin H. Entz, University of Manitoba

Kimberley D. Schneider, University of Guelph

 

Struvite is a sparingly soluble phosphorus (P) fertilizer extracted from various waste streams and is of particular interest for organic crop production, where P deficiencies may limit crop growth. Field trials were conducted in 2017–2019 at Libau, MB, on a high-pH soil with low soil test P (2-6 mg Olsen P kg-1), to evaluate the response of organically managed spring wheat (Triticum aestivum L.), flax (Linum usitatissimum L.), and a multi-year stand of alfalfa (Medicago sativa L.)-grass forage, to differing rates of a commercial struvite fertilizer. Wheat exhibited a grain yield response in two of three years, while flax showed no grain yield response to added struvite. Only the highest rate of struvite addition (90 kg P ha-1) increased alfalfa-grass biomass yield in the year of application, but lower rates also produced yield increases in the second and third years. Alfalfa-grass tissue P concentration and total P uptake were also greater following struvite addition than in the control. Based on these results, struvite is a promising P source for organic crop production, but the direct agronomic benefit to particular crops may differ. Additional research on the role of particular plant P acquisition mechanisms and interactions with soil properties is required to optimize struvite use in organic cropping systems.

Canadian Organic Vegetable Improvement (CANOVI): Growing collaborations for on-farm, decentralized vegetable crop research in Canada

 

Alexandra Lyon, C. Thoreau, and Helen R. Jensen, University of British Columbia

Aabir Dey, The Bauta Family Initiative on Canadian Seed Security, a program of SeedChange 

Canadian Organic Vegetable Improvement (CANOVI) is a 5-year collaborative project launched in 2018 by the UBC Centre for Sustainable Food Systems and the Bauta Family Initiative on Canadian Seed Security, with the goal of contributing to the resilience and growth of Canada’s organic vegetable sector through the characterization and development of varieties that excel in regional organic farming systems. Working with regional farming organizations, CANOVI coordinates a network of on-farm variety trials in which farmer generate and share data about regional variety performance, currently for peppers and carrots. In additions, CANOVI supports three participatory plant breeding projects. These include 1) selection of a long-storing orange Nantes-type carrot with excellent flavour and early vigor; 2) continuation and expansion of farmer-initiated breeding of an early-maturing, blocky, red bell pepper; and 3) decentralized selection of various squash (Cucurbita pepo) varieties based on a range of farmer goals. In this poster, we will elaborate our project goals and methods and explain how farmer groups, NGOs and public universities are working together. We will provide preliminary results from carrot trials as an example of the type of information farmers are gathering and sharing through the trial network, and reflect on our experience piloting the use of SeedLinked, a new app and web platform for participatory variety trials and plant breeding.

Can we improve wheat performance under low phosphorus, organic conditions by diversifying the selection environment and selector?

Michelle K. Carkner and Martin H. Entz, University of Manitoba

It is well established that the selection environment can have a significant impact on the final performance of a cultivar when the selection environment reflects final production conditions. Canada’s first organic participatory plant breeding program (PPB) has produced over 50 lines selected by farmers on their own farms for three years (F3-F6). Many lines were selected under conditions that have been organic for 20+ years, therefore either under sub-optimal soil-phosphorus (P) conditions, or sourced from biological P (manure). Greater understanding of the impact selection environment can have on either greater P uptake or efficient use of P under low P conditions is essential as P is a finite, non-renewable, and geographically restricted resource.  

Cultivars use a range of strategies to buffer against P supply challenges: greater arbuscular mycorrhizal fungi (AMF) colonization, phosphatase root exudation, and greater root growth under low P conditions. Many studies have reported that organic production systems exhibit greater biological activity and greater AMF colonization in host plants than in conventionally managed land. In some cases, this was due to lower inorganic P availability and higher organic P that must be biologically transformed prior to crop uptake.

The present study evaluated PPB parents of a cross (Red Fife x 5602HR), the F3 population, a physical parental mixture, and organic farmer-selected progeny on organic land under (+)P (manure, 25 kg P ha-1) and (-)P (soil test-P 3ppm) treatments. Data presented represents two years, a third will take place in 2022. Three more ‘families’ were evaluated, however, data is not presented. Despite very low precipitation in 2020 and 2021, preliminary data suggests that farmers shaped the population away from either parent towards greater seed size, test weight, protein, and sustained similar yield of both parents. Phosphorus uptake and use efficiency data is being analyzed, however, early data suggests that farmer lines and parents were able to access P pools similarly in 2020. Under extremely dry conditions in 2021, while grain P uptake was similar among all treatments, phosphorus uptake within mature biomass was higher in the progeny than 5602HR, and similar to Red Fife. Mycorrhizal colonization, rhizosphere phosphatase presence, and root biomass will also be investigated.

Is struvite an effective phosphorus source for prairie organic crops?

Joanne Thiessen Martens, University of Manitoba

Struvite is a recycled slow-release fertilizer that may be a good fit for organic production. This research explores options for optimizing struvite use in organic cropping systems in the prairies, considering crop yield response as well as effects on mycorrhizal fungi. 

Effects of Hügelkultur on Soil moisture, Temperature, Electrical Conductivity, and pH, in Southeastern Ontario

Christine Bolle, Carleton University

A practice that is commonly used in permaculture design systems is Hügelkultur, commonly referred to as hügel mound(s). A field experiment at Just Food Farms in Southeastern Ontario was carried out to determine the effects of Hügelkultur on soil moisture, temperature, electrical conductivity, and pH. In two permaculture plots, soil measurements were taken at the centre, half-distance between centre and edge, edge of the hügel mounds, 0.5m and 1.0m out from the edge of four randomly selected hügel mounds in each plot, and control sampling points. Data was analysed using a one-way ANOVA with Turkey’s test for multiple comparisons (SPSS V27). The findings revealed that close to the centre of the mound, the soil moisture, temperature, and electrical conductivity are significantly lower than the other sampling locations. The pH levels of hügel mounds were not significantly different from the control sampling points. These findings expand our knowledge of the impacts of Hügelkultur; however, further research is necessary to determine if Hügelkultur benefits to soil quality justify its utilization as part of sustainable agriculture practices.