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,
Noble M15 the M400. Mounting the engine longitudinally (rather than transversely as on the M400) allowed the engine designers to increase the cooling flow to the engine, which allows the twin-turbo Ford Duratec V6 engine to develop . The engine has been designed to meet European emission standards and the new steel/aluminium space frame has been designed with a view to passing crash test regulations around the world. The M15 is planned to be the first Noble which gains European and US type approval. Like all the Noble M models, the M15 has a steel spaceframe and roll cage covered with graphite-reinforced