Traditionally, potato producers use the late fall – a time when their other crops require less attention – to prep their potato beds for the following spring. The long-established process has its benefits, but also creates concerns, including loss of soil fertility, crop nutrient availability and an increase in greenhouse gas emissions.
A new research project at Canada’s Lethbridge College will work to determine what steps can be taken to ensure the best result for producers, while also moving towards environmentally sustainable agriculture practices. Dr. Rezvan Karimi, research scientist in the Mueller Irrigation Group, is heading the three-year, $446,500 project which is funded by Results Driven Agriculture Research (RDAR).
Current fall bedding practices for potato crops involve irrigation, fertilizer application, plowing and the formation of beds, with an aim to provide favourable soil structure conditions in the spring. Karimi’s team will test three different bedding formations – a traditional fall bedding, a spring bedding after having winter cover crop and a spring bedding with no winter cover crop – to see how each affects the yield, soil nutrient levels and nitrous oxide emissions. This is the first known project in Alberta to study the effect of potato bedding on soil erosion and emissions.
“When producers prepare to bed in the fall and apply fertilizer, there is a big lag time between nutrient application and crop uptake,” says Karimi. “And during the winter, we have soil erosion, especially in the Lethbridge area where we have strong chinook winds, which blow off the topsoil and the fertilizer, so that will decrease the nutrient use efficiency. We also see nutrient loss through nitrous oxide emissions from the soil, which not only decrease the available nutrients for crops but are also an environmental concern.”
The field testing will take place on Lethbridge College’s irrigation research and demonstration farm. The research will combine field experiments and computer simulations to quantify the impact of bedding choices and timing and their interaction with irrigation practices on potato production and soil health. The outcomes will be beneficial to producers, who will have more available data to consider as they look to maximize their potato yield.
“Regenerative agriculture practices have the potential to help Alberta potato producers increase their yields, and nutrient use efficiency while decreasing GHG emissions,” says Clinton Dobson, RDAR Research Director. “Research outcomes from this project will support Federal climate goals, while equipping producers with enhanced and targeted BMPs that address potato industry sustainability and soil health.”
As nitrous oxide emissions are directly tied to the moisture level of the soil, the study will also look at irrigation levels, with an aim to maximize available nutrients for crops while reducing emissions.
“Some farmers over-apply irrigation, adding more water than is needed for the crop,” says Karimi. “We already know irrigated agriculture increases nitrous oxide emissions due to increases in soil moisture availability and decrease of aeration, so we will test how just a 20 percent over-apply of irrigation or a 20 percent under-apply of irrigation than the optimal amount needed will affect the emissions.”
Collaborators on the project include Dr. Roland Kroebel, an ecosystem modeler with Agriculture and Agri-Food Canada (AAFC) – Lethbridge; Dr. Jonathan Neilson, a Potato Health Scientist with AAFC – Lethbridge; Dr. Guillermo Hernandez Ramirez, a soil scientist at the University of Alberta; Dr. Sheng Li, a soil scientist with AAFC – Fredericton; and a yet-to-be-hired PhD student.
Learn more about the project, titled The effects of bedding preparation time, winter cover cropping and irrigation management on yield, soil erosion and GHG emissions in irrigated potato production in southern Alberta, on the RDAR website.