Farmers turned to annual forages and early grazing to deal with the challenges of a variable winter and cool, rainy spring
By Jackie Clark
Farmers growing forages in 2019 faced winterkill and waterlogging, forcing producers to make tough decisions to deal with the challenging season.
“When we have a thaw, there is a lot of meltwater. When it freezes again, that can create ice sheeting in the field which draws heat away from the crowns of the alfalfa plant or it can trap gases from soil respiratory processes next to the crown and smother it,” Christine O’Reilly, forage and grazing specialist at OMAFRA, told Farms.com.
“In particularly heavy clay fields, that freeze-and-thaw action causes the soil to expand and contract, so that can actually jack the taproots of alfalfa up out of the ground,” she added. “The crown of the plant can be exposed and, usually, it’s wind drying out the crown that will kill the plant. (Freeze-thaw) can heave the plant far enough out of the ground that the taproot breaks.”
Perennial crops and winter cereals also lost the protective layer of snow in the winter of 2018-19.
“Snow is a great insulator,” O’Reilly said. “When you don’t have that snow insulating the field, the soil temperature more closely follows the air temperature.”
The result was a lot of winterkill, and a cool, wet spring didn’t help. Higher-than-average snow melt and spring precipitation resulted in some soaked fields.
Alfalfa doesn’t stand up well to waterlogging. “We say it doesn’t like wet feet,” O’Reilly explained. “While it uses a lot of water, (alfalfa) doesn’t like it’s root system sitting in water. The crop is susceptible to drowning out.”
This situation added to the patchiness of perennial forage fields.
“It depended where you were in the province how severe it was,” she said. Estimates from eastern Ontario suggested that “80 per cent of the fields had some level of winterkill,” O’Reilly said.
“This was a year that we saw a lot more annual forage crops going in the ground in general, because of the winterkill that we saw. ... Spring cereals were a popular (choice) and sorghum sudangrass was another.”
The spring conditions led to slower-than-usual pasture development.
“In some cases, because we had such a cool, wet spring, the grasses weren’t growing as quickly as we normally expect,” O’Reilly said.
Some farmers “were running out of hay and silage, so the livestock went out on pasture even though the grasses may not have been at that three- to four-leaf stage,” she added.
Early grazing of underdeveloped pastures can affect recovery, because grasses only begin to re-fill energy reserves in the stem and roots once enough leaves exist to produce more sugar than needed for growth.
“It takes having three or four fully developed new leaves before the plant has energy stored again and it can recover well from grazing,” O’Reilly explained.
Hay yields were largely dependent on rainfall.
“In areas that received fairly regular rainfall through July and August, their hay yields were about average. In areas that had below-average rainfall, yields were below average,” she said.
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