The human hand pollutes...

Humans are overloading ecosystems with nitrogen through the burning of fossil fuels and an increase in nitrogen-producing industrial and agricultural activities, according to a new study.

Ecess nitrogen that is contributed by human activities pollutes fresh waters and coastal zones, and may contribute to climate change. Appearing in the October 8, 2010edition of Science and conducted by an international team of researchers, the study notes how human activity has led to skyrocketing of nitrogen cycle.

The nitrogen cycle--which has existed for billions of years--transforms non-biologically useful forms of nitrogen found in the atmosphere into various biologically useful forms of nitrogen that are needed by living things to create proteins, DNA and RNA, and by plants to grow and photosynthesize. This nitrogen fixation is doen mostly by microorganisms like bacteria.

Since pre-biotic times, the nitrogen cycle has gone through several major phases. The cycle was initially controlled by slow volcanic processes and lightning and then by anaerobic organisms as biological activity started. But the start of the 20th century, human contributions of nitrogen into ecosystems come from an 800 percent increase in the use of nitrogen fertilizers from 1960 to 2000.

Much of nitrogen fertilizer that is used worldwide is applied inefficiently. As a result, about 60 percent of the nitrogen contained in applied fertilizer is never incorporated into plants and so is free to wash out of root zones, and then pollute rivers, lakes, aquifers and coastal areas through eutrophication.

The Earth's population is approaching 7 billion people, and so ongoing pressures for food production are continuing to increase. There is no way to feed people without fixing huge amounts of nitrogen from the atmosphere, and that nitrogen is presently applied to crop plants very ineffectively.

What can be done? The team suggests systematic crop rotations that would supply nitrogen that would otherwise be provided by fertilizers; Optimizing the timing and amounts of fertilizer applications, using traditional breeding techniques to boost the ability of economically important varieties of wheat, barley and rye to interact favorably with the microbial communities associated with plant root systems and do so in ways that enhance the efficiency of nitrogen use, etc

Makes one wonder: is there any one thing we humans have done to impact the planet positively??!