October 16, 2011

To Combat Climate Change, Prof. Wolfe Looks to Soil Health

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In the face of global climate change, there is much uncertainty about future agricultural success and humanity’s ability to provide food for the global community. For the past two decades, Prof. David Wolfe, horticulture, has been helping farmers prepare for the impacts of global climate change to ensure food security for future generations and to protect the environment. He said he believes the best way to accomplish these goals is to maintain soil health.Wolfe’s concern with the environment began with the results of a study he and some colleagues conducted, calculating the bloom dates of lilacs, grapes and apples from 1960 until 2005. The study was published in the International Journal of Biometeorology. Although he recognized before the study that carbon dioxide levels were rising and eventually the temperature would follow suit, Wolfe said he was surprised at how fast temperatures have risen. The study found that the three plant species were all blooming roughly four to eight days earlier than they were in the 1960s. “It’s surprising how fast the climate actually has changed in the course of my career,” Wolfe said. His incentive to research climate change and find solutions comes from the feeling created by his findings, he said.Wolfe has worked with farmers on soil health issues since he was in graduate school at U.C. Davis in the early eighties, but more recently he has been working closely with farmers both in the Northeast and in developing countries. According to Wolfe, sustainable farming practices not only prepare farmers for climate change and make their farms more efficient, but can also sequester carbon dioxide and reduce green house gas emissions. He said that farmers can be a large part of the solution to high green house gas emissions through energy efficiency and properly managed soils and crops. Since 2003, Wolfe has served as the co-chair of the Soil Health Work Team at Cornell,  which has created manuals and new ways for farmers to test soil health.  These methods go beyond the standard chemistry and nutrient load testing common in conventional agriculture. According to Wolfe, many farmers typically focus on eliminating dangerous microbes from the soil instead of fortifying  soil with beneficial microbes. The Soil Health Work Team aims to shift farmers’ priorities away from prevention of harmful microbes and toward increasing the amount of helpful microbial organisms, as this would benefit the farmers’ soils more. Wolfe promotes the benefits of reduced nitrogen fertilizer usage, as significant carbon dioxide is emitted in the creation process and nitrous oxide, which is 310 times more potent than carbon dioxide, is released from fertilizer degradation. Wolfe said that 40 percent of green house gas emissions from farming are in nitrous oxides and that many farmers are not aware of the impact of nitrogen fertilizer. Wolfe has also helped small farmers in Tanzania and Zambia and will be going to Indonesia in January. He said that these countries have severe soil degradation and farmers there do not have the same resources to make up for poor soils that we do in the United States. Here, farmers can invest in irrigation systems and nitrogen fertilizers, but different approaches must be taken in the developing world. Wolfe educates farmers on how to manage their soils efficiently through techniques like legume rotation, inter-cropping cash crops with nitrogen fixing plants and increasing soil carbon. Developing documentation methods to track the carbon storage and emission reduction that farmers are achieving is among Wolfe’s most important projects abroad. With reliable data, farmers could get into the carbon market and theoretically sell their efficiency to large industries that are unable to decrease their own carbon outputs. Wolfe has worked with 30,000 small farmers in Zambia to adopt conservation agriculture practices and 700,000 nitrogen fixing trees have been planted alongside cash crops to increase soil efficiency. This winter, Wolfe said he hopes to help farmers in Indonesia cope with the current uncertainty of when the monsoons come, something that is changing with global climate change and that dictates when they can plant their crops. Indonesia is also having difficulty with soil degradation because many farmers grow oil palm, a cash crop that is very damaging to soil.  According to Wolfe, Indonesia is also one of the leading emitters of carbon dioxide because of its expansive deforestation practices. Efficiency in farming would help not only the farmers, but the emission rates of the country as a whole. According to Wolfe, there are strong links between soil health, conservation agriculture, climate change preparedness and climate change solutions. Productive crops store more carbon in their biomass and eventually decompose in the soil. While some of this carbon is released back into the atmosphere, some of it can be stored as soil organic matter which is generally 60 percent carbon. Wolfe said that organic matter in the soil provides nutrients, holds water and creates structure and better drainage. Increasing organic matter in the soil is also a worthy preparation for the changing climate, as soils with more organic matter are better at withstanding drought and flooding and are home to more helpful microbes that can fight off the dangerous fungi and bacteria that kill crops. Healthier soils would also reduce the need for nitrogen fertilizers that have a particularly negative impact. On top of both studying and communicating the contribution that agriculture can make to green house gas emission and reduction, Wolfe is also an avid writer. Not only does he teach a freshman writing seminar, HORT 1160: Nature Writing and HORT 4600: Cropping Systems Ecology, he has also written a popular science book of his own and hopes to write even more in the future. His book, Tales From the Underground, gives the non-scientist reader a look at how important soil microbes are for the survival of the planet’s biotic community. Wolfe said popular science writing helps him celebrate nature and make others excited about it as well. He said that he prefers not to lecture people about how the world is worth saving, but rather take them on a journey that demonstrates how great the natural world is so that they can decide for themselves that it should be protected.Wolfe is currently working on a book of poetry, some of which relates to his work on climate change, some of which simply expresses his appreciation for the natural world. He said that a lot of the poems have a water theme, either dealing with its potential future scarcity or acknowledging the beauty of its color and unique chemical properties. Wolfe said he enjoys communicating science because it brings him joy through working with people and helping the natural world. Currently, Wolfe developing a  “Climate Change and the Future of Food” course. He is also with several other faculty across campus to establish a “minor” in climate change.

Original Author: Shauntle Barley