GrainsWest Fall 2018

Fall 2018 grainswest.com 25 silts, dropped out. Such lake sediments make fertile soils because they retain moisture and bind minerals. While mountains, ice and water provided the basic ingredients for modern soils, plants and micro- organisms did the rest. Alberta has been divided into a patchwork of soil types known as orders by scientists such as Anderson, who noted that soils are the base for plants, which in turn build more soil. The two shape each other. Modern farm fields were altered for 10,000 years by two main types of plant environments. Forests in Alberta grew where moisture was high thanks to abundant rain, low summer evaporation and retention of water in winter, owing to its northern geography. Southern Alberta experiences a water deficit because it lies in the rain shadow of those ancient mountains that push warm and wet air from the Pacific Coast up where it cools, which causes it to drop most of its moisture west of the province. As well, high winds and hot temperatures combine to produce high rates of evaporation in the southern grasslands. Northern forests and southern Prairies make very different soils. Forests have big tree roots that break down slowly. The rest of the organic matter produced by trees and shrubs falls on top of the soil where much of it stays. On the other hand, grasses store most of their mass underground in small roots that break down quickly, which pumps organic matter below the surface. Prairie grasses produce rich black and brown chernozem soils while the central parkland and northern boreal forest produce grey luvisols. In the middle of Alberta’s Prairie region are large pockets of solonetzic soils. These are created where the parent rock is high in sodium and where ground water and evaporation are relatively high, which brings up salts from lower layers. Len Leskiw has been mapping soils in Alberta for more than 40 years. “It’s in my DNA,” he said of the deep passion for soil science he developed as a farm kid. His consulting firm specializes in soil reclamation and conservation and he has worked with many land developers from Fort McMurray to Lethbridge. He said the province’s soils develop in harmony with climate. Northern latitudes have shorter growing seasons but more water, which favour cereals such as barley, oats and certain types of wheat. All of these can be cultivated annually given abundant ground water and healthy rains that pour onto dense luvisol soils where forest has been cleared. Central and southern Alberta have longer growing seasons where, if rich chernozem soil occurs, the areas can support canola, wheat, rye, barley and oats and pulse crops that include dry peas and beans. But water is relatively scarce, so, in the past, fields had to be left fallow to recover moisture. Irrigation solved some of these problems and now the southern fields also support good forage yields, corn and vegetables such as beets and potatoes. Often called clay-pan soils, solonetzic soils are found in a similar climatic region to chernozems and support much of the same vegetation but the salts generally lower productivity. As an example of how soil type and geographic weather patterns come together, Alberta’s barley belt encompasses an arc of land extending approximately from Vermillion at its northeast to the foothills of the Rockies in the West with its northwest side taking in Lacombe and its southeast limit taking in Stettler and Drumheller. The area curls across the margin of the fertile chernozems and is bordered by more arid land (with solonetzic soil) to the east and south and by luvisols (with lower organic matter) and shorter growing seasons to the north and west. As neat and tidy as soil maps of the province are, scientists recognize that local topography, like the rolling hummocks that the glaciers paved, create soil characteristics that vary by the acre. In 1857, the British-led expedition of Captain John Palliser assessed the agricultural potential of much of the Prairies. He famously deemed southeast Alberta and southwest Saskatchewan to be a near desert unfit for the plough. The area became known as Palliser’s Triangle. Bounded by the United States border, it extended from present-day Cardston and Calgary in the west almost Map:ToddKristensen Where glacial activity created vast lakes, sediments from these water bodies created fertile soils.