P.E.I. farmers appear to be turning the corner in their efforts to rebuild the Island's depleted soil.
Concerns about the state of the Island's soil, and its impact on the agriculture industry, prompted the province to begin monitoring organic matter levels in soil in 1998. The study included 600 sites, with samples being taken, analyzed and recorded about once every three years.
"We want to ensure the soil productivity over time," said Carla Millar, the province's manager of sustainable agriculture.
"We want to ensure that we maintain soil health."
The study now has 20 years of records in the books, with the most recent data from 2018. The results are mixed. They show a decline since 1998 to between two and three per cent organic matter, but that decline bottomed out in 2012, and has been roughly steady since.
"We'd like to see organic matter levels a bit higher, maybe between three percent, 3.5 percent, at least," said Millar.
"At that 3.5 per cent mark the soil is able to do a bit more work for you."
There is no ideal level of organic matter. All soils are different, and it can be particularly difficult to maintain organic matter in P.E.I.'s sandy loam soils.
The province is supporting farmers in a number of measures to increase organic matter.
- Increase in winter cover cropping.
- Erosion control structures, which manage the flow of water through fields.
- Improving crop rotations with soil-building plants.
Ryan Barrett, research co-ordinator with the P.E.I. Potato Board, said soil health has seen declines across eastern North America. This has often been tied to livestock reduction, which means less manure for the soil.
"Here in P.E.I., our hog industry more or less disappeared," said Barrett.
"Our beef production has fallen probably by almost half in the last 20 to 25 years. So that's a lot of manure."
Without a market, the Island can't regrow its livestock industry. Barrett said that leaves crop rotation as the key weapon in the battle to rebuild soil.
What's in that rotation is coming to be understood to matter more than how long the cycle is, said Barrett, maximizing the amount of time there are roots working the soil, and minimizing tillage.
For example a four-year rotation of potatoes, corn, soybeans and turnips that doesn't include grass crops or winter cover crops is not going to help build organic matter. Instead, a farmer might manage a three-year rotation that includes a winter cover crop planted after the potato harvest, and underseeding with a grain crop so there is no need to till the soil again in the spring.
Patience will be key as farmers work to rebuild the soil, said Barrett.
"A century of agricultural practices have got us where we're at today, and it will take more time to build back up," he said.
"It won't take a century, it won't take 20 years, but it'll take time."
Researchers will be back out in the fields in 2021, taking samples to see if the work of farmers is finally being rewarded with some positive results.