On my trips in Xishuangbanna, I came across a large variety of crops, from family gardens to industrial bananas, there is a lot to see in Southern Yunnan. In the surroundings of Jingmai mountain, an interesting field caught my eye:
One row of rubber trees (hevea brasiliensis) inter-cropped with four rows of tea trees (Camellia Sinensis var Assamica). This kind of setting contrasts with the usual vast mono-cultures.
According to several papers (here, here and here), inter-cropping rubber with tea would be advantageous on several aspects such as:
-increased carbon sequestration, leading to a richer soil on the long term.
-reduced run-off and soil erosion, rubber trees are infamously known in Yunnan for affecting the local climate, it is indirectly related to water retention capacity. Rubber tree tends to make the soil impermeable, during heavy rain, water will tend to flow down the slope instead of binding to the soil.
-increased revenues because of a more efficient usage of the field, if you wanted to have the same amount of rubber trees and tea trees in mono-culture, you would need more ground.
-increased stability because the price of rubber and tea leaves are not related.
Are we going to see rubber trees growing around Mahei, Lao Banzhang or Banpo Laozhai? Probably not, because the studies undertaken were aiming at lowland fields. As altitude increase, the price of tea increases and the yield of rubber trees decreases, hence, it would probably not be economical for the famous tea mountains to choose rubber trees as inter-crops.
However, many tea gardens require shade trees and natural tea gardens have room for other crops to be planted, maybe in the future, we could see a more advanced management of tea gardens, using nitrogen fixing plants to increase the soil nutrients and using specific predator hosts in order to keep pest away.
There is a lot of research being done on inter-cropping and tea, rubber, cocoa, coffee, banana, palm oil and other long term crops will be the first beneficiaries of these advancements. Because of the expected population increase (10 billion people in 2050), mankind must launch a ''doubly green revolution'' which implies a production increase as well as a reduction of the environmental impact. Let us hope there will be enough tea for everybody!