Page 628 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

592 part IV Soils, Ecosystems, and Biomes
(a) Soil profile of Gleysol from Atlantic Canada.
(b) Poorly drained soils of the Gleysolic landscape in Atlantic Canada are often used for forage crops. These soils are highly fertile when drainage is improved.
Whitehorse
Victoria
0 500 Kilometres
Iqaluit
Yellowknife
Edmonton Regina
St. John’s
Charlottetown Fredericton
◀Figure 18.17 Gleysolic order. [Photos (a) and (b) Courtesy of Agriculture and Agri-Food Canada, sis.agr.gc.ca/cansis/images/on/ index.html. Reproduced with the permission of the Minister of Public Works and Government Services Canada, 2012; (c) Thematic Soil Maps of Canada: Gleysolic Order, atlas.agr.gc.ca/agmaf/index_eng. html#context=soil-sol_en.xml, Agri- culture and Agri-Food Canada ©, 2010. Reproduced with the permis- sion of the Minister of Public Works and Government Services, 2012.]
(c) Distribution of Gleysolic order in Canada.
hardpan that prevents the free flow of water in the soil and restricts root growth. The three great groups of the Solonetzic order—Solonetz, Solodized Solonetz, and Solod—contain 27 subgroups.
Salinization results from excessive potential evapo- transpiration rates in deserts and semiarid regions. Salts
dissolved in soil water migrate to surface horizons, which will damage or kill plants when the horizons occur near the root zone. The salt accumulation in Figure 18.23b is an example of this process. Under such semiarid condi- tions, commercial evaporite mineral deposits can develop (Figure 18.24, page 598).
Winnipeg
Queébec OTTAWA
Toronto
Halifax
Gleysolic Order Map of Canada
Gleysolic Order
(text continued on page 596)