Soil study breaks new ground
Deep inside the Innovation Space in the Trades, Technologies and Innovation Facility at the Lethbridge College is multiple tons of southern Alberta’s most common soil types that sit inside three massive, custom-built wooden bins, to test subsurface drip irrigation (SDI) systems that work without the variable factors of wind, rain or gophers.
The applied research project is led by Dr. Willemijn Appels, the college’s Mueller Applied Research Chair in Irrigation Science. Alfalfa crops are being grown in the soil, which is fuelled by water delivered through below-the-surface pipes directly to the root zone. Sensors in the soil and Plexiglas windows on the bins give a rare look into how the water moves in various soil types.
“You really want to test subsurface drip irrigation in a representative scale and you need quite a bit of soil to make sure that your water moves in a way that you could experience in the field,” says Appels, in a media release.
“We decided to create that experimental setting indoors so we can do experiments year round and get a better look in fine detail at what happens with the water and the crops when you’re irrigating them from within the root zone.”
The types of soil being used for the study include Grassy Lake sand, Lomond loam, and Coaldale clay which were donated by local farmers to be used in the testing. Each bin is three-by-six metres and nearly a metre deep, providing an almost perfectly controlled environment to test subsurface drip irrigation. SDI is relatively new to southern Alberta, but it has existed for decades in countries with water scarcity, and its main benefit is efficiency.
“In Alberta, we have some weird little corners or parcels here and there that could use a different type of irrigation and not automatically suited to pivot irrigation,” says Appels. “If you could make subsurface irrigation work on those, economically as well as from the agronomic or irrigation perspective, then that could be really interesting.”
Appels’ research is important to the local industry because it can feel like a leap of faith for farmers who are accustomed to seeing pivots deliver water in an obvious spray, where subsurface drip irrigation happens entirely out of sight.
“The research is teaching and training growers to really know their soils and how their soils work with a totally different way of irrigation,” says Marc Jongerden, installation manager with Southern Irrigation, the college’s partner in the endeavour.
“We believe in this and we know this will be one of the systems for the future. We believe in it for water usage, to spread water more efficiently and to open up for acres.”
The one-year research project has support from Southern Irrigation, and funding from a $50,000 Natural Sciences and Engineering Research Council of Canada Applied Research and Development grant, and another $20,000 from the Regional Innovation Network of Southern Alberta. Appels’ position was created as part of a $3.1-million gift from Lloyd and Dorothy Mueller, announced in 2014.