Tiling has been the way of life in the south central Minnesota region for as long as Pat Duncanson can remember. Many county outles were put in about 100 years ago and has been a tradition that has had a direct impact on the value of farmland.
“It is the culture we grew up with,” Duncanson says. “Drainage and tiling are important parts of crop production.”
I wonder how many home and community gardeners would know that sub-irrigation called "tiling" (not to be confused with tilling) is used for both drainage and irrigation in professional field farming. Long time readers of this blog might know from prior posts here and here.
Further, how would anyone outside of farming know that tile used in field agriculture is plastic rather than ceramic? Tile in farmspeak is the same corrugated perforated plastic pipe used to irrigate and aerate the plants in the first sub-irrigated raised beds here in Brooklyn.
From Cyclopedia of American Horticulture 1904
Why does this matter to the public at large? It matters because it has a significant impact on the quality of public education about modern methods of growing plants, edible plants in particular. Ergo, it has a significant impact on the quality of urban agriculture and the availability of high quality locally produced fresh food.
The public gets a steady drumbeat of propaganda from institutions like the USDA Extension Program about arcane drench and drain plant watering methods but little or nothing about sub-irrigation. Even then, the highly misleading term "self-watering" is used.
What is most egregious is that the same professional educators who know about agricultural sub-irrigation use the unprofessional term "self-watering" when communicating with consumers.
Who would know that "self-watering" and tiling both mean sub-irrigation? Consumers might search on the words "self-watering" but are highly unlikely to ever search the word "tiling" when looking for information about growing fresh food.
A personal experience with a very well-known school garden here in Brooklyn illustrates the point about the word tiling and sub-irrigation. The school garden was built over a former parking lot that was broken up and topsoil trucked in. Now for some reason there is a very significant drainage problem. The school garden manager struggles to overcome it with marginal results. The quality of the plants is significantly below average.
The problem with this school garden is not unique. It exhibits the very same problems that farmers have faced and solved with tiling (sub-irrigation and drainage).
Duncanson says there is a direct relationship between nitrogen use and drainage. Tiling has allowed Duncanson to manage nitrogen more precisely.
“If we go into a farm that isn’t well drained, we have experienced higher nitrogen losses some years. Any mobile nitrogen is lost through denitrification,” he says. “If a farm is tiled, we can fine-tune the nitrogen rates.” Duncanson says they use a lower rate of nitrogen applied to tiled farms.
If the school garden manger knew about tiling and sub-irrigation the school garden would likely double production while saving water and reducing labor time in coping with the drainage problem.
Unfortunately, the information is poorly understood in the urban gardening community where much of the education is based largely on experiential, anecdotal and folkloric knowledge rather than professional, peer-reviewed and science-based academic information.