The Effect of Eucalyptus Detritus Leaves on Soil Fertility

Eucalyptus are tall trees native to Tasmania and Australia. They are grown commercially for their oil and leaves. These leaves are thick and leathery and have a pungent aroma when bruised or crushed. The plant can tolerate some cool weather but as a general rule it does best in areas where the temperature stays around 60 degrees Fahrenheit.

Background

Eucalyptus contains around 300 species and is prized commercially for its oil. The trees are also known as Blue Gum Trees. The name Eucalyptus is derived from the Greek "well covered." This is a reference to the flowers that have a cup-like covering that they shrug off when the bud blooms. If cut or damaged the tree exudes a great deal of sap that has many medicinal uses. Eucalyptus are known as the food of koalas and the major plant species in Australia.

Significance

The trees have a bad reputation as extensive water users and contributors to soil depletion. They do need copious quantities of water and their huge taproot can find moisture even in the driest areas. They are huge feeders in order to keep up their rapid growth. However, much of this is replaced in dropped leaves and debris that carpets and composts into the ground. There has been concern that the dropped leaves are poisoning the ground since they contain allopathic properties thought to affect soil fertility.

Considerations

In Southern China where there are a great many Eucalyptus plantations, the plants are grown on what was barren land. With the practice of inter-cropping, or adding more plant species around the trees, the soil has improved. Much of Australian-grown Eucalyptus are grown in poor soils with little nutritive benefit. The trees produce much of their own food through photosynthesis and their detritus adds nutrition to the soil. They are also important wildlife habitats and food sources.

Misconceptions

The truth is that Eucalyptus recharge the earth and add nutritive content to soil. A study done on a 16-year-old eucalyptus plantation showed an increase in soil fertility from 1.2 percent and 2.5 percent up to 1.78 percent and 3.25 percent in the 16 years it was operating. Additionally, it was shown that poor fertility around the trees was related to the loss of the leaves and branches which local people used for fuel. If these had been left to become mulch the return of nutrition would have been a complete cycle.

Benefits

Growing Eucalyptus has numerous homeopathic and natural benefits. The trees are sometimes referred to as Fever Tree since it is often cultivated for its antiseptic qualities and grows in swampy areas. There are three different oils distilled from Eucalyptus. Medicinal oils, industrial oils used for flotation and aromatic oils for perfumes. The leaves are dried and used for tea, and the medicinal oils are used for disinfectant, antiseptic and a stimulant. The curative powers of Eucalyptus have been known for centuries and were used by indigenous people.