QUALITIES OF THE SOIL OF A TEA GARDEN

Mountains are creations of nature that have taken millions of years to reach their current grandeur. Mountains are formed of layers of soil that can be traced back to different eras in history. These layers of tea soil are formed of a variety of soil and rock types, housing different microcosms of bacteria and little organisms that produce nourishment for vegetation and regulate how nutrition is maintained or transported in the pores of the soil. These grounds constitute the fertile basis for the tea bushes to develop. Simultaneously the difference in composition of each square affects how the leaf is nourished and what the quality will be at harvest.

The importance of soil

healthy tea garden soil

Soil is the foremost factor of importance for the growth of the tea bush. It provides a fertile environment with specifications that can only be obtained at this specific area. However, mountains are no easy grounds to work on, and mountain flanks can be steep. This makes them often inaccessible with large machinery or harvesting equipment. Sometimes these areas are even difficult to be accessed with man-held equipment, making it an uneconomical undertaking for the producer. Therefore, more and more farms tend to move towards easier working environments, but in doing so revert to leveling mountain flanks, or cutting out and embanking parts of the mountain to artificially create better accessible grounds.

Unfortunately, such practices lead to loss of good fertile topsoil, and the creation of infertile farms that, instead of being a location on the mountain flank, become situated inside the energetic boundaries of the mountain. Such farms inevitably become dependent on artificial nourishment for there is no natural nourishment left in the soil, while the farm has been positioned in an energetically inactive inner-part of the mountain.

The importance of topsoil

To provide one concrete example, at the natural farm of Mr. Fumiaki Iwata in Nara, absolute importance is given to the topsoil of all farms, and the soil in which the roots of the bushes are nestled. Since the tea plantation is located high in the mountains surrounding Nara, most gardens are positioned on steep mountain flanks. Fumiaki only uses a hand-held harvester for all his gardens. One of his farms has very distinct soil differences and the bushes growing on this mountain flank, although they are growing right besides each other, reach with their roots in a different composition of soil. The results are extraordinary as the same bushes, getting nourishment from a different layer of ground, obtain a completely different flavor pattern.

Two types of soil

The two types of soil that are accessible on this mountain flank are 1) a geological composition dating back one to two hundred million years to the time when dinosaurs lived on this earth (Cenozoic era), and 2) a geological composition dating from 5 to 6 million years ago when mankind started appearing on this planet (Mesozoic era).

What is interesting is that the bushes growing on this specific mountain flank are divided in a group reaching into the soil of the Cenozoic era, while another group gathers nourishment from the Mesozoic soil, and yet another group has roots reaching into both types of soil, providing all three groups with utterly different specifications.

Soil from lake Biwa

tea soil different layers

Another specific trait of the earth in Tsukigase is the soil that was created by lake Biwa. In the past, lake Biwa[1] is said to have reached into the Iga mountain basin, covering one area of what is now Tsukigase. This area is now called the ‘old Biwa lake’. The lake Biwa that is currently located in Shiga prefecture, used to (approximately 3 to 6 million years ago) stretch from Mie prefecture to the Iga mountain basin, and then gradually repositioned itself northward, where it made its way to its current location in Shiga, roughly 60km detached from its original location.

According to the book “The moving lake, lake Biwa” by Takuo Yokoyama[2], Lake Biwa is believed to have originated approximately 6 million years ago. Its original location is said to have been the mountain basin in what currently is the western side of Iga prefecture in the Tsukigase rock formation. As a result, this means that the origin of lake Biwa is the area where Fumiaki’s farm is currently situated. Moreover, it is this lake that has created the soil that is referred to above as no. 2), the soil from the Mesozoic era.

The earth shows remnants of a large river running through the area, which can be derived from the variety of large round pebbles in the ground, in addition to an amalgamation of soils that are foreign to this specific vicinity, and must have been carried along from distant territories. Furthermore, at the bottom of the river a layer of thick clay – as the types used for pottery – has accumulated, and overall a varied range of minerals that differ in color and texture are included in the soil.

“You are what you eat”

The producer strongly believes that it are the qualities of the soil in the first place that affect the specific traits of the tea grown in this area, and that this is exactly what makes the tea from this region unique. However, the uniqueness of the earth cannot be brought about in the tea when excessive fertilizer is mixed in with the soil, because the artificial nourishment would easily overpower the delicate traits of the ground. Therefore, the producer strongly believes that especially for this type of environment it is necessary to uphold natural production methods. By this he means to manufacture a tea that is nourished with the energy and power of foodstuff that has garnered in the soil for over hundred millions of years.


[1] Lake Biwa is the 670.4 km² wide freshwater lake in Shiga Prefecture, northeast of Kyoto.

[2] 『移動する湖、琵琶湖』京都自然史研究所発行、横山卓雄著.

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