Fall bedding in potato fields allows for soil preparation work to be done when growers typically have more time and labour available to them. In this system, growers usually irrigate, broadcast fertilizer as needed, plow, and then form beds into which they plant the following spring.
For this edition of Roundtable, Spud Smart asked the following five experts to weigh in on their experiences with fall bedding.
- Louis Claassen, a potato producer in Vauxhall, Alta.
- Darin Gibson with Gaia Consulting based in Manitoba. Gibson is co-author of a study that looked at bed planting techniques in Manitoba.
- Harold Perry, a potato producer near Chin, Alta.
- Sheldon Wiebe, a potato producer near MacGregor, Man.
- Arjan Woordman, a potato producer at Taber and Vauxhall, Alta.
A COMMON PRACTICE IN ALBERTA
Fall bedding is commonly used to prepared fields for planting to potatoes the following spring. The equipment used to form the beds preserves sufficient trash cover to limit erosion. Orienting the beds at right angles to the prevailing winds reduces the impact of wind on soil erosion. The construction of reservoirs between beds prevents soil loss from water erosion caused by snowmelt and heavy spring rains.
In Alberta, fall bedding and reservoir tillage is common. Arjan Woordman started fall bedding his potato fields as soon as he moved to Alberta from the Netherlands 12 years ago.
“We are on a little bit heavier soil, and if we make the hills in the fall, that allows moisture to get into them,” he says. “They freeze up nice, and quite typical for winters here, we’ll get a Chinook and it thaws. Then it freezes and thaws a few more times through the winter, and that creates a really nice mellow hill in the spring.”
Harold Perry agrees. His family has been growing potatoes for 40 years, and for the past 25, fall bedding has been a regular practice on the farm.
“You have to have that freeze-thaw action throughout the winter that loosens up compaction from your tillage practices from the fall before. Since we started fall ridging, our soil has better flocculation with more air spaces, and we have noticed higher sets,” says Perry. “For best results, all clods need to be in the hill with good soil contact so the freeze-thaw breaks apart the clods (when water freezes it expands nine per cent). If a clod ends up on top of the hill, it is not as likely to get enough moisture in it to get the freeze-thaw action that will break down the clod.”
Perry seeds a cover crop in the fall beds. “The cover crop will reduce soil erosion from wind and water, and the roots from the cover crop will also break down clods,” he says. “The root exudates also help suppress diseases and sequester carbon through photosynthesis into the soil. In the spring we power hill directly into our fall ridged rows and then seed.”
A fall bedding and reservoir tillage (diking) implement performs both the tillage and hilling operations. In fall prior to spring planting of potatoes, the field is tilled with a deep tiller or a double disc. Next, deep subsoil tillage is performed, hills are constructed, and reservoir dikes or depressions are formed between the rows. The reservoirs capture water from melting snow and increase soil moisture.
In spite of the aggressive fall tillage, surface trash cover is preserved, reducing the potential for wind erosion. In spring, hills are packed with rolling wire baskets to break up soil clods that survive the freezing and thawing cycles over the winter, the hills are reshaped and the reservoirs are removed. The potatoes are then planted directly into the pre-formed hills. After planting, the final hilling is carried out and new reservoirs are formed between the rows.
Louis Claassen has been growing potatoes near Vauxhall, Alta. since emigrating to the area from the Netherlands in 2005, and practicing fall bedding since then.
“We are here on heavy soil and to get good conditions for planting, we have to fall bed,” he says. “It’s important to get a good moisture level in the hills for the spring to keep the lumps down.”
Claassen says they start fall bedding right after fall harvest. “We go in there with a disc ripper, and then a disc to break up the lumps. After that, we fall bed by forming the ridges, and then we irrigate right after. We need the moisture in the hills in the fall, and it stays better in their during wintertime.”
Woordman and Perry, too, are on heavier clay and loamy soils in southern Alberta, and they both say fall bedding on heavier ground is key to growing potatoes. According to Woordman, the practice isn’t difficult, although there are some equipment needs.
“To make the rows, we use a dammer diker,” he says. “Some guys will use pocket makers, some guys use cage rollers. It varies a little bit, depending on preference.
“We usually use the cage roller option just to pack the hills down because our soil tends to lump up pretty good,” he adds. “So after packing that hill down, it stays fairly moist, it freezes up nice and it mellows out really nice in the spring.”
MANITOBA GROWERS TRY FALL BEDDING
Fall bedding has proved so successful in southern Alberta, it has gained the attention of Manitoba growers who are fall bedding by subsoiling, shaping beds and forming reservoir pockets in the fall prior to a potato crop. According to Darin Gibson with Gaia Consulting in Portage la Prairie, Man., the expectation is these procedures improve the soil environment and increase yield.
“Raised beds are more exposed to the air and sunlight and may warm up quicker in the spring, allowing for earlier planting,” he says. “Reservoir pockets capture snowmelt and prevent runoff into lower areas of the field, which causes saturated soils. This allows the field to dry more quickly and also facilitate earlier tillage and planting in the spring.”
Gaia Consulting undertook a study a few years ago to determine the effect of fall soil preparation on potato yield and grade. While the study didn’t prove that soil warmed faster in the spring than through conventional methods, penetrometer readings indicated that sub-soil tillage significantly reduced soil density in the 0-12 inch soil profile tested in three of four fields.
Compacted soils occur when the weight on the soil from farm equipment exceeds the ability of the soil to support the weight. Soil compaction can cause excessive clod formation and slower water infiltration, especially in wheel tracks. Potatoes in particular are sensitive to the compacted soils, resulting in lower yield and poor quality tubers.
“The use of sub-soil tillage can reduce soil compaction and improve water infiltration and root development,” says Gibson. “This improves water and nutrient uptake by the plant, ultimately leading to greater yields.”
Sheldon Wiebe, potato grower at MacGregor, Man., first tried fall bedding in 2011. He says they liked what they saw, and they’ve been doing it on all their potato acres since 2013.
“On our sandy soil type, we are always aware of sand blowing, so the crops in rotation are zero-tilled, and so that means little or no tillage after the potato crop,” he says. “We are firm believers in breaking the hard pan of the soil and we can achieve this with fall bedding. Also, we are seeing less runoff in the spring because of the hills formed and the pockets we leave.”
Wiebe uses a dammer diker with 34-inch spacing, with wings on each shank to make the hill shape. The stubble is left standing mid-row. The advantages to fall bedding for him are numerous.
“We do fall bedding on all our soil types, from coarse sand to the more darker loamy soils,” he notes. “We find the fall bedding makes for loose soil in the spring, thus creating a healthier root system for the potatoes. Also, it creates more area for the tubers to grow, more efficient fertilizer uptake, water uptake and better filtration.”
He also says preparing the fields in fall with fall bedding allows him to start planting potatoes earlier in spring “because of less ponding and more surface to warm the soil because of the hills.”