Laura Carruthers, PhD student in the College of Agriculture and Bioresources. (Photo: Submitted)

Spud-tacular innovation: USask PhD student investigates nutrient-efficient potato varieties

The United Nations has designated May 30 as the International Day of Potato to raise awareness of the potato as an invaluable food resource.

By Laura Carruthers

The potato is the most consumed non-cereal crop in the world. Its ability to grow in many different climates around the world, coupled with its impressive nutrient-dense outputs, make it an all-star product when addressing the global food security crisis.

To identify ways to make potato production systems more sustainable, I am investigating how potato crops use nutrients and how different aspects of potato production influence soil nitrous oxide, or greenhouse gas emissions.

Working with Dr. Kate Congreves (PhD) at the University of Saskatchewan’s (USask) College of Agriculture and Bioresources, I hope to identify more-efficient potato varieties that producers can grow to reduce inputs required and nutrients lost from the production system. By producing the same (or more) yield with reduced inputs, we improve the sustainability of production systems.

Nutrient-use efficiency is the ability of a plant to obtain nutrients (like nitrogen or phosphorus) from the soil and utilize those nutrients to produce yield. Potatoes have notoriously low nutrient-use efficiency, and producers on the Prairies use high fertilizer rates to combat this. ­­­

This means a large portion of the fertilizer applied can be left behind in the field and be lost to the environment through runoff, leaching, or greenhouse gas emissions. This is costly for producers and potentially detrimental to the environment.  

With pressure on the agriculture industry to reduce fertilizer use and associated emissions, and an expansion to the irrigated land in the province, identifying potato varieties that utilize nutrients most efficiently will be beneficial to producers.

Laura Carruthers, PhD student in the College of Agriculture and Bioresources. (Photo: Submitted)

For this project, we grew six potato varieties with a range of nitrogen and phosphorus fertilizer rates at two sites over multiple years. We collected potatoes from each plot and analysed them for nutrient content. With this information, we were able to calculate nutrient-use efficiency using multiple indices. We also monitored greenhouse gas emissions over the course of two growing seasons to identify when peak emissions were occurring and what was causing them.

One interesting finding from my research is that earlier maturing varieties had higher yields and nutrient-use efficiency relative to other varieties. The Dark Red Norland, Sangre and Poppy varieties had consistently high yields and higher nutrient-use efficiency than other varieties across three years of the study, demonstrating that genetics are playing a significant role.

This will be important going forward as climate change will likely increase drought prevalence in the Prairies. By growing varieties that can thrive with fewer nutrients and less water, we can use those resources elsewhere.

I believe research is critical in these key staple crops. Potatoes can be consumed with little to no processing, store well, and can be grown around the world. I aspire to do work that contributes to food security, and I have been lucky to do that with this project. 

To help battle food insecurity at a local level, we have donated more than 3,200 kilograms of potatoes harvested from my research projects over the last two years to multiple organizations in Saskatoon.

This research contributes directly to the USask Agriculture Signature Area of Research and is funded by the Saskatchewan Ministry of Agriculture (Agriculture Development Fund), the Natural Sciences and Engineering Research Council of Canada through a graduate scholarship, and the USask Agriculture Signature Area of Research. The research is also supported by the Saskatchewan Seed Potato Growers Association who donated the potato seed for the project.

The scholarships and different opportunities available for graduate students at USask have allowed me to expand my horizons. From being hands on in the lab and making management decisions in the field to collaborating with other professors within the college on new research, I have been fortunate to study here. I am incredibly grateful for the College of Agriculture and Bioresources and my supervisor Dr. Congreves for fostering such a supportive environment.

Laura Carruthers is a PhD student studying plant sciences in the College of Agriculture and Bioresources at the University of Saskatchewan.


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