Soil work begins with microscopic assessments

Lab research helps farmers understand the life underground as a first step toward improving the health of the soil

OYEN, Alta. — Yamily Zavala gets excited every time she identifies a new life form under her microscope.

Squirming nematodes, fungi, bacteria and amoeba indicate there is a circle life in the soil to rebuild structure and help grow healthy plants on the surface.

The head of the Chinook Applied Research Association (CARA) Soil Health Laboratory at Oyen is collecting samples from 20 sites in Alberta for the next five years to assess the health of soil and work with farmers to improve it.

The most common problem on the Prairies is compaction and a lack of organic matter.

A number of principles must be considered to improve the soil and repair past mistakes so part of her mandate at the new soil lab at Oyen is training farmers to look more critically at their soils.

Rebuilding the soil starts at the surface and what lies beneath, where there should be a network of plant roots, micro-organisms and channels to hold water and oxygen.

“It has to be a package that comes together,” she said during a field day at the Chinook Applied Research Association at Oyen.

Combining a diversity of plants with different roots systems helps build crumbly soil with organic matter to hold water and nutrients.

The right micro-organisms feeding on each other and organic material are needed to help break down roots and open up the soil. As organic matter increases, it can hold up to 20 times its weight in water. When livestock grazing is added the repair job can begin.

The lab provides information to understand the soil beyond nutrient limitations and excesses. Lab staff can evaluate biological and physical properties while the chemical components are provided through a commercial lab partnership. The information can be used to build a bridge for soil health improvements based on site specific constraints.

Producers can send in soil samples and receive information on active carbon, soil aggregation, texture and bulk density. The level of bacteria, fungi, protozoa, nematodes and root mycorrhizal colonization is also rated as low, medium or high.

None of these life forms can be seen with the naked eye. For example, nematodes are about 200 to 400 micrometres. A micrometre equals one millionth of a metre.

“It is very important that we keep the soil healthy for these microbes. The system is able to control itself,” she said.

“The more diversity you have in there, the better for the crops,” she said.

There is no exact percentage of what the population needs to be but research is continuing.

In addition, she has experimented with cocktail mixes of legumes, tap roots like tillage radish and cereals. Her large plots already show an improvement where the surface feels spongy and quality has improved even in a dry area like Oyen where hard brown soil dominates.

For more information, visit www.CARAsoilhealthlab.ca.

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