Friday, November 18, 2011

Leaves and Water: It's Not What But Where, and Nutrient Pollution in the Tea Industry

One way of looking at tea is that it just leaves and water. Here is a photo I took in Philadelphia, which shows leaves and water:

There's really not much here that looks like tea. Occasionally, fallen autumn leaves will "infuse" in streams or standing water, producing a rich dark brown infusion which looks a lot like black tea. But this is not happening in this photo, which shows freshly fallen rain.

Furthermore, most of us would probably agree that tea is generally a good thing, yet in this photo, neither the leaves nor the water are in a place that is terribly convenient. The water has flooded the entrance of a driveway, and the leaves are covering the sidewalk, and are slippery.

It's not what, but where, that matters:

Sometimes, in life, we just don't have enough of a certain resource in order to achieve some sort of goal. People go hungry for lack of food, or businesses can be limited by availability of some supply or raw ingredient in their production process. There is often no other way to remedy these sorts of problems other than finding whatever resource is needed.

In our modern society, most problems are of a different nature. Things are in the wrong place. These sorts of situations are often able to be solved in ways that turn them into a win-win situation, in which a problem in one area becomes a valuable resource in another. A good example of such a solution is recycling, which can turn waste (which is costly to dispose) into raw materials or inputs in an industrial process to create something of value.

Another good example of a problem of things being in the wrong place is nutrient pollution. Nutrients, such as nitrogen and phosphorus, are often limiting factors in both ecosystem growth and agricultural productivity. For this reason, commercial agriculture often treats crops with synthetic fertilizers, rich in nitrogen. These fertilizers are often applied liberally, providing far more nitrogen than is actually necessary for the crops. In the case of some plants or crops, excess nitrogen can be taken up by the plants in the form of nitrates and nitrites, which are harmful to eat in quantity (think of the issues associated with eating too many nitrite-treated meats). The remainder is not utilized by the plants, but runs off into the water. Once the nitrogen is in the water, it can damage or destroy aquatic ecosystems through a process called eutrophication. Eutrophication is a major problem worldwide, on all continents, and affects roughly half of lakes throughout North America, Asia, Europe, and South America (less in Africa, because Africa is less developed). Other problems include soil acidification, and contamination of the water supply with nitrates.

Over-fertilization in Tea Production:

The over-use of fertilizer is unfortunately a problem that exists in the tea industry.

The tea plant is a plant with very low nutrient requirements (think of how it grows naturally on rocky outcroppings in the Wuyi mountains), but it is an evergreen plant that naturally invests in its leaves for several year's worth of use. The continuous harvesting of leaves puts a heavier demand for nutrients on the plant, so it becomes necessary to add some form of fertilizer to replenish these nutrients.

Organic agriculture sometimes helps, but organic certification alone is not necessarily a guarantee that the right level of fertilizer is being applied. (see this source) The key solution to the problem of over-fertilization is to apply less fertilizer. Organic fertilizer still contains nutrients, and still causes problems when there are too many nutrients.

Fortunately, there are relatively easy ways for these problems to be addressed. Furthermore, as is usually the case of problems caused by things being in the wrong place, the outcome is actually a win-win situation. One solution is to use lime fertilization instead of conventional fertilization schemes. Another is to simply use less total nitrogen. There is some evidence that using less nitrogen actually results in slightly higher yields of tea. See this source for a study of Japanese tea fields, backing up these ideas.

I am hopeful that over time, we eventually completely solve not only the problem of nutrient pollution, but all other problems of things being in the wrong place. In the case of nutrient pollution, the solution is already known, it just needs to be implemented. For more problems in our world, we need more brainstorming, experimentation, and study. But I find it empowering to think about things in this way.

What are some problems that you see in the world around you that are examples of things being in the wrong place?


  1. I have just completed a Master Gardening Course, sponsered by Cornel University and the Cooperative Extension. One of the things they emphasize is the overuse of fertilizers, which just run off and pollute both land and water. It was amazing to me how little is really needed to get optimum results. Read your labels and follow them exactly! You can even get overly exuberant with compost, although the margin for error there is much wider.

  2. Yes! So many things in life are like this, I often need just a little of something in order to achieve some sort of goal, and too much can cause all sorts of unintended negative consequences.