Monitoring climate’s impact on soil
Alberta Agriculture and Forestry monitors how dry the climate can get in the province.
“Alberta Agriculture and Forestry uses weather stations to monitor conditions and form the basis of regular moisture situation reports,” Ralph Wright, Manager, Agricultural Meteorology, Alberta Agriculture and Forestry, says.
According to the Agricultural Situational Moisture Situational Update from July 29, 2019, the weather patterns throughout Alberta have remained largely consistent through the month. The already dry areas in the Northern Peace Region and throughout Southern Alberta have remained as such.
The wetter areas, which the report classifies as being south of an east to west line from Grande Prairie down to Calgary and diagonally to Lloydminster, have received rain regularly. Due to a surge of thunderstorms during the month of July, that rainfall has been heavy more often than not.
“Over the past 17 days, two major events have been responsible for bringing upwards of 80 mm or more moisture to a large area stretching from Camrose in the south, to Manning in the north-central Peace Region,” Wright says. “Previously, the northcentral Peace was relatively dry, but last week this changed when upwards of 100 mm of rain fell in some locales, bringing much needed moisture.”
A map on the Government Alberta website indicates that some areas of the province have a greater potential for water erosion based on soil and land characteristics of the SLC and climate.
An article on the website prepared by Douwe Vanderwel and Syd Abday states that soil loss due to water erosion reduces crop yields and proper management of resources can serve as a good preventative measure.
“Returning crop residue to the soil helps to replace organic matter and plant nutrients,” Vanderwel and Abday’s article states. “Rotations which include forages return more residues to the soil and increase fertility. Manure applications and legume plowdown are also good sources of organic matter and nutrients.”
Vanderwel and Abday identify snowmelt and rainfall as being the driving forces for water erosion on the prairies. Bare soils, steep slopes, long slopes that have no interruption, silty soils, soils low in organic matter, and soils with an impermeable layer are very vulnerable to erosion, according to the article.
“Alberta research shows that switching to reduced or zero tillage systems is needed to protect soils on steeper and longer slopes from erosion,” the article from Vanderwel and Abday says. “Zero tillage systems minimize soil disturbance to maintain as much crop residue cover as possible to conserve soil moisture and prevent erosion. Long-term zero tillage also increases soil organic matter and improves soil quality and fertility.”
Not only does water erosion have an impact on soil, wind erosion also impacts it. An article titled Wind Erosion Control by the late John Timmermans and Frank Larney, talks about how the Dust Bowl of the 1930’s resulted in damaged crops and unusable soil.
“The Dust Bowl crisis prompted prairie agriculture to seek ways to control and prevent wind erosion,” the article by Timmermans and Larney says. “Much progress has been made since then with many individuals devoting countless hours to improving the management of prairie soils.”
According to the article, approximately 900,000 hectares of soils in Alberta were damaged in the 1980’s due to strong winds. There are several types of wind erosion, the article states, with the most common being the loss of topsoil and nutrients considered essential to crop production.
“Wind erosion has plagued prairie agriculture for many decades,” the article says. “However, with today’s farming equipment and practices, wind erosion control can easily be a part of your crop and pasture management systems.”
Unfortunately, the article is very clear about the fact that despite the use of preventative measures, wind erosion can still be caused by drought and constant strong winds. Emergency controls can be used, according to the article, and those controls include soil ripping to surface clods or covering the soil with manure or straw.
“Wind erosion is a serious problem which threatens the long-term productivity of prairie soils,” the article emphasizes. “By using appropriate conservation farming techniques, you can reduce wind erosion under most conditions. The soil is a precious resource which needs your protection.”