Urban Ag & soil management blooms at Niagara Parks Botanical Gardens
“Soil is a biggie in the vegetable garden,” says Charles Hunter, Curator Instructor of Vegetable, Rose and Herb Gardens at Niagara Parks Commission Botanical Gardens & School of Horticulture. Hunter was speaking at the Toronto Master Gardener Technical Update at the Toronto Botanical Garden.
In 2005 the soil in the new vegetable beds were in very poor shape after years of growing with synthetic fertilizers.
“Using synthetic fertilizer is Band-Aid approach. It is not sustainable,” says Hunter.
With the introduction of sustainable soil management, the soil dramatically improved. Techniques and material used to improve the soil included:
- Using organic amendments, horse manure, compost, manure tea mixed with molasses, and cover crops
- 7-year crop rotation
- Companion planting
- Proper access to garden beds (i.e. less soil compaction by staying off the bed)
An interesting aside, the vegetable beds are still being tilled prior to transplanting/direct seeding. No-till is the technique used by many gardeners and farmers who wish to preserve soil structure and soil ecology. Have a peek at Megan’s blog on No-till vegetable gardening.
Hunter explained why they still tilled their vegetable beds every spring.
Hunter explained that no-till works better for monoculture, and that it is very difficult when you are growing many varieties. (I didn’t understand this reason…)
Another reason Hunter cited in favour of tillage was that vegetables are annuals, which prefer growing in high bacterial soil. Tilling destroys fungal mycelium and increases the bacteria in the soil. (For an alternative perspective, Jeff Lowenfels & Wayne Lewis in their book, Teaming with Microbes, says, and I quote: “Even bacterial dominated soils need to contain some fungi to maintain soil structure and microbial diversity. Soil food we gardening practice requires that the soil be disturbed as little as possible when it comes to annual and vegetable gardens…” Tilling is required only when the beds are first converted from woodland or perennial beds to vegetable beds. )
Hunter also mentioned that they used a spader instead of a rototiller to till the soil. Rototilling pulverizes the soil. Spaders, a conservation soil preparation tool, disturb the soil structure far less than rototilling. (This is a good thing!)
If you not familiar with spaders, this Penn State Extension video explains how it works.
Because of the changes in soil management, not only did the soil improve but the vegetable harvest also increased.
In 2005, the 800 square metres (8,600 square feet) of vegetable beds produced a mere 1,000 kg (2,200 lb. in 8,000 square feet).
By 2012 the same plot of land produced 3, 500 kg (7, 700 lb.) of vegetables.
That’s the power of good soil management!
Soil type: Clay loam soil
Depth ranges from 0.5 to 1.5 m (1.6 ft. to 4.9 ft.) with a limestone bedrock base.
The pH varies from 6.8 to 7.5
USDA Hardiness Zone: 5b