Tea gardens in the upper reaches of Feitsui Reservoir use low-phosphorus fertilizer to cut pollution, making the tea taste sweeter

To reduce water pollution in the Feitsui Reservoir, the Tea Research and Extension Station of the Council of Agriculture and the Feitsui Reservoir Administration worked last year with Pinglin tea farmer Huang Shu-huang to trial a low-phosphorus fertilizer in his tea garden. The results showed that it not only effectively lowered the phosphorus content of the soil, but the tea leaves grown also improved in quality, with higher theanine content.

Rational fertilization improves Feitsui Reservoir water quality

The area around Pinglin and Shiding upstream of the Feitsui Reservoir has a history of tea cultivation spanning several decades. In Pinglin, for example, the tea growing area is about eight hundred hectares, there are more than a thousand farming households, and annual output is about 500,000 metric tons, with the area known for its pouchong tea.

The Feitsui Reservoir, which has long supplied water to the Greater Taipei area, has faced the looming threat of eutrophication over the past twenty to thirty years, and excessive phosphorus and nitrogen are among the causes. A 1991 study by the Institute of Plant and Microbial Biology, Academia Sinica, pointed out that tea cultivation areas need to pay attention to rainwater washing away soil in order to reduce the pollution load from runoff. A 2007 study by Kuo Chen-tai and others also noted that "tea plants need to be fertilized four to six times a year, and the nitrogen and phosphorus fertilizers applied cause tea gardens to export higher amounts of nutrients, so tea gardens may be one of the main sources of pollution."

Therefore, in order to prevent fertilizer remaining on farmland from entering the reservoir with rainwater and affecting water quality, the Tea Research and Extension Station has been promoting "rational fertilization" in recent years. Last year, the Wenshan Branch of the Tea Research and Extension Station cooperated with the Feitsui Reservoir on a pilot project with Pinglin tea farmer Huang Shu-huang, applying fertilizer with half the phosphorus content in his tea garden, hoping to reduce the phosphorus content of the soil while also taking into account the farmer's harvest.