Christmas tree cultivation has shifted toward the production of higher-quality trees, increasing land quality expectations as well. Indeed, some species of tree, such as the Fraser fir, are unable to grow on low-quality, marginal farmland. Flat or gently rolling land is preferred to that with steep slopes and inclines, which is prone to erosion and fluctuations in fertility. Noticeable obstructions, such as rocks, fences or significant underbrush, are also undesirable. Like all crops and plants, Christmas trees require a specific set of nutrients to thrive. There are 16 elements crucial for growth; of those, three are obtained through air and water: hydrogen, carbon,
Bicycle tree As of February 2013, some 85 systems of this manufacturer and type in use can hold 17,323 bicycles, all in Japan. Bicycle tree A bicycle tree or "cycle tree" or "bike tree" is a bicycle parking system that resembles a tree in shape. There are a few types that have been developed. Some are manual, some use mechanical means to move the bike, assisting the bike by raising into a particular spot, they can handle between 5-20 bicycles depending on size. They are made by various companies in Europe and North America. Still others, like the one made by JFE