Christmas tree cultivation and oxygen. Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, chlorine, manganese, molybdenum, iron, and zinc are obtained from the soil. If the necessary elements are not available in the local soil, nutritious fertilizers are used. Other important soil considerations include pH and drainage. Certain types of soil are preferable, depending on the type of tree. Pine trees are usually better adapted to a sandy or sandy loam soil, while white spruce trees and fir trees, such as the Douglas-fir, prefer fine-texture loams and clay loam soils. Some trees grow well in all types of soil, but in any case,
Douglas (surname) form of the given name is "Dùbhghlas"; the Irish language form it is "Dúghlas", and "Dubhghlas", which are pronounced . According to George Fraser Black, in southern Argyllshire the surname is an Anglicised form of the surnames "MacLucas", "MacLugash" (which are derived from the Gaelic "Mac Lùcais"). ---- ^ Mark Douglas professor of Christian ethics at Columbia Theological Seminary Field Marshal Robert Douglas was firstly created baron, and then count, in Sweden. His main fief was the town of Skänninge, and his wife brought in the estate where they had the manor of Stjernorp erected. His descendants generally continued to