Agriculture News

How to help microbes improve your soil

Published on 04.04.2019 by Richard Kamchen


There’s an entire ecosystem in your soil that’s as complex as the Serengeti.

Among the teeming life underground are microbes, which aid in nutrient and carbon cycling, improving soil structure and suppressing plant disease.


“Your soil microbial communities cycle the nutrients that plants need for growth. Without them, you wouldn’t have that,” says Lori Phillips, a research scientist in soil microbiology with Agriculture and Agri-Food Canada.

Microbes break down carbon and continually cycle it in the system. A diverse and abundant soil microbiome will sequester more carbon.

“And more carbon in your soil means more nutrients, better water holding capacity and better structure,” Phillips says.

Microbes are hugely important for soil structure.

Fungi produce compounds that help increase aggregation. And better soil structure means less compaction, greater water infiltration and better channels for roots to grow in.

A healthy soil biological community also can help suppress plant diseases.

“They can either directly outcompete for niche resources or they can prey on plant pathogens,” Phillips says.

Taking care of soil microbes results in better soil nutrition, carbon cycling, soil structure and suppression of plant disease. Tweet this

Harmful practices

Some farming practices, however, can potentially harm microbials.

Tillage, for instance, can be a catastrophic event for microbials as it destroys their habitats.

“I believe that the key to increasing soil health and the microbial population of the soil revolves around keeping live roots in soil at all times,” says Manitoba farmer and soil health advocate Ryan Boyd.

A healthy microbiome can help resist damage, be that from tillage, high levels of fertilizer and herbicide, and even floods and droughts.

“We also try to limit our use of seed treatments and insecticides, and use fungicides in crop sparingly,” Boyd adds.


Monoculture is another detriment as it typically causes a decrease in microorganism diversity. Recovery from a catastrophic event would take longer because some of the system’s functional resilience would have been lost, Phillips says.

“We try to grow pastures that are diverse in species and manage grazing as to have green growing plants as long as possible throughout the year, feeding the soil biology with root exudates,” Boyd says.

Diversity also goes for his annual crops.

“We have a diverse crop rotation and will occasionally grow a forage mixture of annual species for grazing or stored feed,” Boyd says.

Cover crops and manure

Any practices that can increase diversity and carbon in the system will promote healthy microbiomes.

Cover crops increase the types of carbon, or food, entering the system, thereby boosting below-ground diversity, Phillips says.

She adds that manure and compost also increase the types of food available for microorganisms.

Bottom line

Microbial abundance and diversity are keys to soil health. Farming practices such as crop rotation, increased crop diversity and cover crops help build microbes, experts say.

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