@農자료창고

Yields on farmland have increased 38% since 1989 but the cost of inputs including fertiliser jumped about 325% during the same time. Photograph: CactuSoup/Getty Images

According to the US Department of Agriculture's Economic Research Service, the number of women-operated farms more than doubled in the 25 years between 1982 and 2007. In fact, female farmers now make up the fastest-growing sector of the country's changing agricultural landscape and nearly 1 million women - approximately one-third of total domestic farmers - list farming as their primary occupation. The National Women in Agriculture Association calls it "breaking the grass ceiling." It's that and more.

Some are choosing to farm as a way of maintaining continuity, tending land that has been in their families for decades. Others, however, are choosing farming for many different reasons, among them the desire to do something concrete, constructive and quickly gratifying; to tweak gender norms; or simply to have better control over their work lives. Many see their efforts as overtly political.

"Women are leading the way in sustainable and organic agriculture," Lindsey Lusher Shute, executive director of the National Young Farmers' Coalition told Truthout. Although she works for the Coalition full time, as co-owner of the Healthy Roots Community Farm in Tivoli, New York - 100 miles north of the city - she is involved intimately in all aspects of growing fruits and vegetables in a sustainable manner.

A Midwesterner whose grandfather farmed, Lusher Shute's career was launched in Brooklyn, New York, where she helped create the East Williamsburg Community Garden in 2002. "We grew vegetables, ornamental plants and flowers," she begins. "I loved the interface between gardening and the community. The community started out divided between residents who'd been there for a long time and newcomers, but the opportunity to work together on something to beautify the neighborhood led to friendships that might not have happened otherwise. We held weekly barbecues, and the garden became a place to work out community tensions and problems."

Lusher Shute, now 34, ultimately left Brooklyn, married, had children and moved upstate. Nonetheless, the desire to farm led her and her farmer spouse to buy 70 acres of farmland. "It is critical for farms to ring cities," she said. "We employ eight or nine people, some of them year-round and some seasonal, and grow vegetables and produce eggs for a community-supported agriculture program that runs 22 weeks a year."

As Lusher Shute speaks, her enthusiasm and pride are obvious. "For me, farming is an amazing career. It allows you to be an entrepreneur and offers flexibility. I like being able to put high-quality, healthy food in the hands of people. It's something you can feel good about. It's a way to give back and at the same time earn a paycheck."

But this is not to say that it is easy. "Over the next 20 years, 70 percent of the nation's farmland will change hands," she said. "At this point the social circles you see farmers running in are largely male. They're typically very buddy-buddy and may never think to involve younger female farmers. It's hard to know why, if it's gender-driven discrimination or if they've just known each other forever and are comfortable doing what they've always done. Plus, the young people may want to do things differently."

In addition to being ignored or greeted with overtly sexist derision, Lusher Shute reports that a lot of young farm women are working hard to figure out how best to balance parenthood with their work lives. Indeed, the Young Farmers' discussion board is filled with questions, concerns and suggestions about achieving an effective balance. A closed thread called "Moms and Dad/baby wearing on the farm" includes Emily's post: "Instead of carting my screaming child out into the field where we'll both be uncomfortable, I've decided to take over more of the business end of things," she wrote. "And God knows, there are tons of things to be done on that end of the farm operation - applying for grants, responding to emails, keeping up the website and blog, writing our newsletters, organizing our CSA, hiring interns and staff. Although it's been really hard to be out of the field, I have come to the conclusion that all the other stuff is essential to running our farm and I'm grateful to have enough flexibility to be able to tailor a role with my son in mind."

While some might see this as falling into traditional gender roles - with mom in the house and dad on the tiller - 30-year-old Debbie Weingarten, one of four co-owners of the 15-acre Sleeping Frog Farms in Cascabel, Arizona, notes that for her, the decision to focus on business tasks was driven by pragmatism. "My son is 30 months old, and I have had a very difficult time trying to integrate him into my farm responsibilities. He has been a difficult sleeper, which has left me pretty sleep-deprived and not operating on all cylinders. I also have a 7-year-old stepson who we are homeschooling, which further splits my time. As my journey into motherhood has progressed, I've found it easier to take care of the backbone of the business."

Like Emily, Weingarten answers emails, organizes the farm's CSA and develops fliers and promotional materials. But she also makes deliveries, milks the goats, and runs their farmers market. "In between I raise my children," she wrote in an email. "I definitely see this as becoming more of a central conversation between women as more young families become involved in agriculture." That said, Weingarten admits that the stress - worry over uncontrollable things like the weather as well as fear of a pest infestation or CSA closure - can impact the household in negative ways.

Still, Weingarten underscores how much she loves farming and farm life. "There is something inherently nurturing in food production," she wrote. "It feels important, like a tangible piece of the revolution."

Discrimination and Isolation 

For Leigh Adcock, executive director of the 16-year-old, 3,200-member, Women, Food and Agriculture Network, the social and political empowerment of women is always front and center. The group's goal? "To strengthen the role of women from the farm house to the White House." Nonetheless, Adcock concedes that obstacles abound and are significantly worse for women living in remote, rural areas. "Farm women face three primary challenges," she said. "First there is discrimination. Then there is geographic isolation. Many farms have no close neighbors. Cultural isolation is also a problem. Women in male-dominated professions need to talk to each other and see others like themselves, but a network like ours exists primarily on the Internet. It's a Catch-22. Women in the most need of a network are usually in isolated areas with little Internet access and have to go to a library or community college to use a computer."

Then there's outright backlash, especially against those who favor sustainable or organic methods. Several years ago, in 2010, Adcock reports that the National Soybean Association and the Corn Growers Association teamed up to create an ongoing campaign called Common Ground. "They wanted to put a softer face on big ag," she said, "and have used women to say that genetically modified organisms give us better-tasting fruits and vegetables that are naturally resistant to insects. The message is that we should not worry about hormones or GMOs in our food."

Like many farmers, Adcock disagrees and, through WFAN, promotes chemical-free agriculture.

Likewise the Oklahoma-based National Women in Agriculture Association, founded by Dr. Tammy Gray-Steele in 2008. "I grew up on a farm in Wewoka, Oklahoma," she said. "My family was awarded 40 acres and a mule. We still have the 40 acres, but now five family members collectively own 2,600 acres there. I live in Oklahoma City, where I do urban farming and outreach in the heart of the low-income community."

Each year, Gray-Steele brings approximately 50 schoolkids to her 10-acre plot. "We run a highly structured program," she said. "Between October 1 and the end of November, we do outreach. Then from early December to mid-March, we sponsor a once-a-month class in sustainable horticulture practices, covering everything from pest control to planting. In April we begin implementing what we learned. We grow greens, purple peas, berries and squash and have another acre of raised beds and a flower garden. In the summer the kids make snow-cones from fresh fruit grown on the land and run a weekly farmers market. What they make, they take. The participants are typically 60 percent female. I always tell the kids, you'll always have a job if you work in agriculture." Secondary skills, including the ability to work cooperatively and market and advertise their produce are emphasized simultaneously.

"Farming Was 'Women’s Work' "

The multiplicity of tasks involved in farming is part of what drew 33-year-old Sarah Sohn, a former public interest lawyer, to farming. As a child growing up in an affluent Detroit suburb, she loved annual trips to the County School Farm, an educational demonstration project. Visits to a neighboring family's 30-acre "hobby" farm were even more pleasurable. Her parents, both of whom grew up in Seoul, South Korea, further captivated her with stories about the gardens in their ancestral homeland. "I can't explain it," she laughs, "but growing things became an obsessive delight to me. And when I get interested in something, I want to learn everything about it."

As a high school student, Sohn got hooked on a Learning Channel program called "Gardening Naturally." Her interest developed even further following a summer internship at an Ann Arbor farm and a part-time job in a natural-food store that introduced her to wheat grass, sprouts and other organic items. Volunteer work at a garden affiliated with a homeless shelter during college gave her additional experience. Nonetheless, she went to law school and, for nearly five years, represented the urban poor.

"In 2006, we moved to Maryland for my wife's job," Sohn said. "I was home with our daughter, who was then under 1. After a while I began looking for legal work, but the downturn in the economy meant that none of the nonprofits in the area were hiring. I knew that I really needed to get out of the house at least one day a week so started looking at farms because I wanted to be outdoors, move and clear my head." By the summer of 2007, Sohn had secured work on two organic farms, one 285 acres and the other a smaller, family-run operation. Several years later, in the winter of 2013, she became the manager of the 3-acre Side by Side Farm in Freeland, Maryland, and is presently in the process of leasing land to create her own small farm in partnership with the Camellia School in Arlington, Virginia. The farm will serve special needs children. "Horticulture gives participants - adults as well as kids - the skills to work efficiently. There are also built-in opportunities for a sense of accomplishment, from growing something to selling it to a CSA, farmers market, restaurant or individual."

"Traditionally, for the vast majority of human history, farming was women's work," she said. "Then it changed into a masculine, patriarchial model with a man on a giant tractor trying to beat nature into submission. But small is not just beautiful and quaint. It's economically viable and smart. You can manage an acre and make a living. If you manage well, you can gross $20,000 per acre per year."

Can, of course, does not mean will and Leigh Adcock of the Women, Food and Agriculture Network cautions that 75 percent of women farmers earn less than $25,000 a year. At the same time, she notes that many women find the work deeply fulfilling and their efforts often extend far beyond the fields in which they toil. And thanks to the many groups that have developed, women farmers now have the tools to advocate for better policies - from more government support for family farms to subsidies for farmers markets and local food promotion.

Deborah Maud, who works with Sarah Sohn at the Side by Side farm in Maryland, said she loves farming because "it puts you in an intimate relationship with the Earth. You're caring for it, and, in turn, it's caring for you." At the end of the day, however, she said what motivates her is not particularly ideological. "I believe people across the economic spread should have access to good, clean, healthy food. Women know they can provide it and can develop the confidence to do what needs to be done. We sometimes have to be aggressive, pushing to learn how to change the oil on a tractor or to weld, but we have the endurance and sustaining strength to feed ourselves and our neighbors."

http://truth-out.org/news/item/20047-women-lead-the-way-in-sustainable-and-organic-agriculture

토양침식, 토양 악화, 석유 가격, 벌의 군집붕괴, 인구 성장이란 요소가 갖는 의미는 극명하다. 산업문명은 잠식되고 있다. 방향을 바꾸지 않는다면, 앞으로 10년 안에 세계의 식량 종말을 시작으로 역사에서 침몰할 것이다. 

이렇게 재미나고 좋은 농사법이 있습니다.

그런데도 농약에 의존하여 땅을 망가뜨리고, 생태계를 어지럽히겠습니까?

농무부 장관 Vilsack 씨는 몇몇 최근 발표에서 기후변화가 작물 재배를 어렵게 할 것이란 인식을 확대시켜야 한다고 촉구했다. 옮은 방향으로 나아가는 것이지만, 필요한 변화를 일으키기 위해서는 돈과 인력에 중요한 전환이 있어야 한다. 

Vilsack 씨는 작물 사이에 덮개작물을 심는 등과 같은 사이짓기를 하고, 작부체계에 가축을 통합시키는 것을 지원하여  다양한 작부체계를 개발함으로써 농업을 더 탄력적으로 만들어야 한다고 경고했다. 그는 “다양한 작부체계와 이후 기후 위기를 관리하고 농업을 변화시킬 또 다른 방법들을 통해 얻을 보존 혜택에 관하여 우리의 소통을 개선하기 위해 더 나은 일을 할 수 있기를 바란다”고 말했다.

지난 여름의 끔찍한 가뭄이 기후의 영향을 훨씬 더 명백하게 만들었다. 그럼에도 불구하고 현재의 예산 부담에서는 필요한 변화 -미국 농무부가 앞으로 대규모 단작에서 벗어나겠다고 하는 약속- 를 만들기가 매우 어려울 것이다. 그러나 그러한 노력의 최종 결과는 환경과 농촌 공동체, 장기적 생산성, 자원의 보존을 향상시킬 것이다. 

역설적이게도 높은 옥수수 가격이 대규모 단작(한 농지에서 해마다 옥수수나 콩을 심는 방식)을 증가시켰다. 이는 Vilsack 씨가 바라는 다양한 작부체계와 정확히 반대되는 것이다. 

한편, 미국 농무부의 연구예산 가운데 비중이 매우 적은 더욱 다양하고 탄력적인 농생태적 작부체계를 지원하는 프로그램은 예산이 삭감될 위기에 처해 있다. 여기에는 유기농업 연구와 지도 계획(OREI)과 지속가능한 농업의 연구와 교육 프로그램(SARE)이 포함되어 있다..

장관이 지지하는 복합적 작부체계는 이미 수확량을 더 높인다고 알려져 있다. 그러나 세 가지 작물이나 그 이상의 작물을 더 길게 돌려짓기하는 것이 더 큰 이득을 가져오기에, 두 작물 체계 -중서부의 옥수수-콩과 같은- 에 대한 그의 지지는 여전히 지속가능하지 않은 체계에 너무 결속되어 있는 것이다. 

생산성 이상의 것

이미 알려졌듯이, 기후변화에 대한 적응만이 아니라 왜 우리의 농업을 고쳐야 하는지에 대한 많은 이유가 있다. 또 여기에는 Vilsack 씨가 강조하는 생산성 문제보다 더 많은 것이 포함되어 있다. 예를 들어 세계의 바다에 생기는 약 400개의 죽음의 구역은 주로 비효율적인 농법에서 발생하는 질소에 의한 것으로, 중요한 해산물 생산 지역을 손상시키고 있다. 

천연가스로 만드는 대부분의 인공 화학비료로 인해 과잉된 질소는 이산화탄소보다 300배나 지구온난화를 일으킨다는 아산화질소의 주범이다. 

미시시피강 유역에서 광범위한 측정과 모델링에 기반하여 수행한 코넬 대학 Blesh 씨와 Drinkwater 씨의 최근 중요한 논문 은 더욱 다양한 농업이 관행농의 옥수수나 콩 농업보다 질소를 덜 남용한다는 것을 밝혔다. 이러한 다양한 농업은 유기적으로 질소를 생산하는 콩과식물과 덮개작물, 그리고 작물을 살찌우기 위해 분뇨를 활용하여 영양분을 순환시키는 작물과 가축의 통합 등을 포함한 돌려짓기를 활용한다.

다양한 농업은 여러 이유로 수확량이 더 낮다. 대규모 단작 체계에서 최근에 전환했다든지(악화된 토양이 회복하는 데 시간이 걸리기에), 작물이 유기적 퇴비보다 인공 화학비료에 반응하도록 육종되었다든지, 다양한 작부체계에 최적화된 영양 대응에 대한 연구가 부족하다든지 하는 것 때문이다. 이는 이러한 부정적 측면에 대한 연구를 통해 크게 개선될 가능성이 높다는 것을 뜻한다. 

또한 우리는 다양한 농업이 관행농의 대규모 단작에 기반하는 농업만큼 생산적이고 수익성이 있다는 것을 밝힌 아이오와 주립대학의 훌륭한 장기, 농장 규모 연구가 있다. 그리고 다양한 농업은 단순한 농업보다 더 적은 양의 농약과 화학비료를 필요로 한다. 좀 더 많은 양의 노동력이 필요하지만, 농민은 농약과 화학비료 같은 값비싼 투입재에 대한 지불을 줄임으로써 재배면적당 더 많은 수익을 유지할 수 있다. 그리고 조작되지 않은 훨씬 값싼 작물 품종의 씨앗으로 이렇게 다양한 체게에서는 조작된 씨앗을 키우는 것만큼 생산적일 수 있다.

큰 상승효과 덕분에 농촌 공동체에 더 나은 것이다(더 많은 돈을 지역에서 순환시킴). 또한 농약에 덜 노출되기에 농민과 농업노동자만이 아니라 그걸 먹는 소비자에게도 더 낫다.

Vilsack 장관도 기후변화와 함께 작물 해충이 증가할 가능성을 지적했다. 다양한 체계는 적은 농약 요구량으로 실증되듯이 해층 피해에 훨씬 탄력적이다. 

이처럼 제안된 변화는 농업 투입재 시장을 장악하고 있는 대기업에게는 좋지 않을 것이다. 기후변화와 화석연료에 기반한 산업과 마찬가지로, 몬산토와 바이엘은 그들의 시장을 유지하고자 맞서 싸울 것이다. 그들은  Blesh와 Drinkwater 씨가 지적하듯이, 충분하지는 않으나 제한된 방식에서는 도움이 될 수 있는 제초제에 의존하는 무경운이나 정밀농업 같은 투입재에 기반하는 농법을 밀어붙일 것이다. 그리고 그들은 계속하여 농약 사용량을 증가시킬 유전자변형 제초제 저항성 작물을 밀어불일 것이다.

이러한 기업들이 정부의 무상불하지에 연구시설을 세우는 데 엄청난 투자를 할 것이고, 의심의 여지없이 최대한 돈을 쏟아부을 것이다. 예전에 썼듯이, 농업 과학기술에 대한 대통령 위원회(PCAST)의 보고서는 농업 연구 방향에 대한 잠재적 악영향은 전혀 우려하지 않으며 이러한 "민관 협력"을 찬양하고 있다. 그 보고서에 대형 기업들이 개입되어 있다는 것은 놀라운 일이 아니다. 

그래서 농무부 장관이 추구하는 바를 확실하게 하도록 노력을 기울일 것이고, 그래야 점점 환경과 식량생산에 위협이 될 지속가능하지 않은 농업을 계속하려는 피할 수 없는 압력에 버틸 수 있다. 과학자들이 우리가 가진 진정한 대안을 대중과 정책결정자들이 이해하도록 돕는 데에 특히 중요한 역할을 수행할 수 있다. 

저자: Doug Gurian-Sherman(생명공학과 지속가능한 농업에 대한 전문가. 식물병리학 박사). Doug' 블로그

http://goo.gl/mVOax

This summer, record temperatures and limited rainfall parched vast areas of U.S. cropland, and with Earth’s surface air temperature projected to rise 0.69 degrees Celsius by 2030, global food production will be even more unpredictable, according to new researchconducted by the Worldwatch Institute. Although agriculture is a major driver of human-caused climate change, contributing an estimated 25 to 30 percent of global greenhouse gas emissions, when done sustainably it can be an important key to mitigating climate change, write report authors Danielle Nierenberg and Laura Reynolds.

Because of its reliance on healthy soil, adequate water and a delicate balance of gases such as carbon dioxide and methane in the atmosphere, farming is the human endeavor most vulnerable to the effects of climate change. But agriculture’s strong interrelationships with both climatic and environmental variables also make it a significant player in reducing climate-altering emissions as well as helping the world adapt to the realities of a warming planet.

“The good news is that agriculture can hold an important key to mitigating climate change,” said Reynolds, Worldwatch’s food and agriculture research associate. “Practices such as using animal manure rather than artificial fertilizer, planting trees on farms to reduce soil erosion and sequester carbon, and growing food in cities all hold huge potential for reducing agriculture’s environmental footprint.”

The United Nations Food and Agriculture Organization estimates that the global agricultural sector could potentially reduce and remove 80 to 88 percent of the carbon dioxide that it currently emits. By adopting more-sustainable approaches, small-scale agriculture in developing countries has the potential to contribute 70 percent of agriculture’s global mitigation of climate change. And many of these innovations have the potential to be replicated, adapted, and scaled up for application on larger farms, helping to improve water availability, increase diversity, and improve soil quality, as well as mitigate climate change.

This report, Innovations in Sustainable Agriculture: Supporting Climate-Friendly Food Production,discusses six sustainable approaches to land and water use, in both rural and urban areas, that are helping farmers and other food producers mitigate or adapt to climate change—and often both. They are:

• Building Soil Fertility: Alternatives to heavy chemical use in agriculture, such as avoiding unnecessary tilling or raising both crops and livestock on the same land, can help to drastically reduce the total amount of energy expended to produce a crop or animal, reducing overall emissions.

• Agroforestry: Because trees remove carbon dioxide from the atmosphere, keeping them on farms whenever possible can help mitigate climate change. Agroforestry also keeps the soil healthier and more resilient by maximizing the amount of organic matter, microorganisms, and moisture held within it. Agroforestry also provides shade for livestock and certain crops, and creates habitats for animals and insects, such as bees, that pollinate many crops.  

• Urban Farming: Growing food in cities can mitigate the greenhouse gas emissions released from the transport, processing, and storage of food destined for urban populations. Urban agriculture also increases the total area of non-paved land in cities, making urban landscapes more resilient to flooding and other weather shocks, while improving the aesthetic value of these landscapes.

• Cover Cropping/Green Manure: Cover cropping, also known as green manure, is the practice of strategically planting crops that will deliver a range of benefits to a farming system, and often plowing these crops into the soil instead of harvesting their organic matter. Planting cover crops improves soil fertility and moisture by making soil less vulnerable to drought or heat waves. Cover crops also serve as a critical deterrent against pests and diseases that affect crops or livestock, such as corn root worm or Rift Valley fever, particularly as warmer temperatures enable these organisms to survive in environments that were previously too cold for them.

• Improving Water Conservation and Recycling: Innovations in water conservation, including recycling wastewater in cities, using precise watering techniques such as drip irrigation rather than sprinklers, and catching and storing rainwater, all help to reduce the global strain on already-scarce water resources.

• Preserving Biodiversity and Indigenous Breeds: Growing diverse and locally adapted indigenous crops, such as yams, quinoa, and cassava, can provide a source of income and improve farmers’ chances of withstanding the effects of climate change, such as heat stress, drought, and the expansion of disease and pest populations. Preserving plant and animal biodiversity also reduces farmers’ overreliance on a small number of commodity crops that make them vulnerable to shifts in global markets.

By tapping into the multitude of climate-friendly farming practices that already exist, agriculture can continue to provide food for the world’s population, as well as be a source of livelihood for the 1.3 billion people who rely on farming for income and sustenance. If agriculture is to play a positive role in the global fight against climate change, however, agricultural practices that mitigate or adapt to climate change will need to receive increased research, attention, and investment in the coming years.

climate and ag_FINAL.pdf

We want to raise $15,000 to help keep Reynaldo's project alive. Go to www.indiegogo.com/creesmanu to donate and find out more. 

Reynaldo Ochoa is an inspiration to the people of Manu in the Peruvian Amazon rainforest. For the past 20 years he has dedicated his life to finding new ways of living in balance with his environment. By encouraging farmers to plant trees with their crops and enabling families to grow fresh organic produce he is helping to forge a sustainable future for the region, both protecting the environment and allowing local people to flourish.


It hasn't always been this way. When Reynaldo moved to the rainforest over 30 years ago he cleared the forest just like everyone else.. When the soil could no longer produce crops he moved to new land and started again. After years of working like this he realized that if people continued in this manner there would soon be no forest left.. And so he began learning about sustainable farming and started to experiment with his own land. He tried lots of different methods and eventually found a system that works.. Now he uses the waste from his chickens to feed pond algae which, in turn, feeds the fish.. The waste from his sheep he uses to fertilize the land for crops and he plants nitrogen fixing trees and vines to regenerate the soil.. The system is akin to permaculture and works much as nature would without the introduction of a monoculture.
Reynaldo helps farmers all across the region to plant trees with their crops as part of Crees agroforestry project. These trees enable the forest to regrow and also replenish the soil with nutrients, thus reducing the need to clear new land for farming. The trees absorb Co2 from the air and can be used for carbon offsetting. Each tree is protected for between 15 and 40 years after which they can be used as a source of sustainable timber.




Reynaldo helps share his knowledge not just by working with commercial farmers but also by helping local people start gardens of their own where they can grow crops in an organic way. The aim is to help improve peoples nutrition and provide an income through the sale of any excess produce.



Since he began, Reynaldo has started over 350 gardens and planted over 30,000 trees. He does not drive a car and uses bio gas in his home (produced from his own families waste!). As a pioneer in organic farming he lives a truly sustainable existence.



Though he has been working in sustainable agriculture for more than 20 years, Reynaldo currently works with the CREES foundation to help forge a sustainable future for the Manu region of Peru, in the heart of the Amazon rainforest.




The film project.

At the beginning of 2011 Crees foundation Journalist Nick Werber got together with filmmaker Dan Childs to produce a series of films about the Crees foundation's work in the Manu region of Peru. After 6 months of planning they eventually flew to Peru in July and spent the next 3 months living in the rainforest, filming every day in searing heat and dense humidity. They filmed a range of wildlife including Macaws, Tapirs and Monkeys and covered all areas of Crees work from scientific research to community projects. They filmed volunteers getting out of bed at 5am to check small mammal traps and survey the Macaw activity at the clay lick, and helped plant trees with Reynaldo Ochoa, the star of this film. Filming with a Canon 7D and 550D, Nick and Dan managed to create cinematic short films on a low budget. Returning to England in late 2011 They began the editing process, eventually cutting 4 films for Crees. This being the first in the series.

Music "To build a home" by Cinematic Orchestra.

농민이 농지에 인공 질소비료를 뿌리고 있다. eutrophication&hypoxia/Flickr

최근 Nation 기사에서, 아름다운 Elizabeth Royte 씨는 수압 분쇄 또는 프랙킹과 식량 공급 사이의 직접적인 관계에 대해 캐냈다. 요컨대, 화학물질을 섞은 액체로 암반을 파괴하여 천연가스를 추출하는 것은 오염된 물을 남긴다 —그리고 오염된 물이 우리가 먹는 작물과 가축에 들어갈 수 있다. 

그러나 식량/프랙킹의 관계에는 우리가 알던 것 말고 다른 사실도 있음이 최근에 알려졌다. 미국 농업은 인공 질소비료에 지나치게 의존하고, 질소비료는 천연가스를 연료로 하는 가공을 통해 합성된다. 미국의 천연가스 공급이 프랙킹을 통해 더욱더 공급되면, 농민들이 사용하는 질소비료도 프랙킹을 통한 천연가스에서 더욱더 생성될 것이다. 만약 대형 농업이 화학비료의 수요를 충족시키고자 값싼 프랙킹 가스에 매혹된다면, 화석연료 산업은 프랙킹 사업에 대한 규제를 깔아뭉개고 반대측과 맞설 강력한 동맹을 얻을 것이다. 

프랙킹한 질소비료(N으로 알려진)의 성장에 대한 잠재력은 엄청나다. 2000년대 기존의 미국 천연가스의 공급원이 고갈되어 가격이 치솟을 때, 미국의 화학비료 산업은 주로 트리니다드토바고처럼 기존의 천연가스가 여전히 상대적으로 풍부한 해외로 나가 채취했다. (이에 대해 2010년  Grist의 기사를 참조) 2009년 미국 농무부 문서의 아래 도표는 2000년대 국내의 질소비료 생산이 얼마나 빨리 변화했는지 보여준다. 

질소비료의 시대: 2000년대 질소비료 생산이 미국의 천연가스 가격의 상승으로 해외로 이전됐다. Source: USDA

한편, 프랙킹 붐은 미국의 천연가스를 갑자기 풍부하게 만들었다 —그리고 가격을 끌어내렸다. 현재 미국 천연가스의 비티유(Btu) New York Times에서 최근 보고했듯이, 2008년보다 75% 이하의 비용이 든다. 한편, 질소비료의 가격은 높은 작물 가격으로 강한 수요가 꾸준하여 높은 수준으로 유지되고 있다. 그러한 상황 —낮은 투입재 가격에 최종 생산품에 대한 높은 가격이 더해지는— 은  미국 시장에서 호황을 누리는 값비싼 질소비료를 생산하기 위해 값싼 미국의 천연가스를 활용하는 기업의 잠재적 노다지 광맥을 의미한다. 오늘날, 베네수엘라 해안 저편에 위치한 미국의 주요 질소 수입원인 섬나라 트리니다드토바고는 2000년대 초반의 미국과 같은 상황에 놓여 있다: 기존에 쉽게 채굴하던 천연가스의 공급이 다하고 있다. 2012년, 국제통화기금(IMF)는 현재의 채굴속도로는 그 국가에서 2019년까지만 채굴할 수 있을 것이라고 추산했다.

Kay McDonald가 다음 글(http://blog.daum.net/stonehinge/8727580)에서 표현했듯이 별로 놀랍지 않은데, 산업이 프랙킹 붐의 이득을 취하러 미국으로 되돌아오기 시작하고 있다. McDonald는 천연가스 수송관에 인접한 아이오와주에서 이집트 회사인 Orascom이 14억 달러의 새로운 대형 질소비료공장 건설사업을 9월에 발표한 사실을 지적했다. Wall Street Journal에 따르면, "값싼 미국의 천연가스 공급과 세계의 가장 중요한 식량 공급자라는 국가의 역할"이 미국 시장으로 이집트의 거인을 끌어들였다.

그리고 난 뒤 미국의 화학비료 거인 CF Industries는 11월에 루이지애나와 아이오와에 있는 기존의 질소비료공장의 확장사업에 38억 달러를 투자한다고 발표했다. MarketWatch는 "낮은 천연가스 비용과 높은 곡물 가격의 이득을 취하기 위한" 움직임이라고 보고했다. 같은 달, 미국 소유의 농산업 기업인 CHS는 노스다코다에 질소비료 공장을 세우기 위해 12억 달러를 투자하겠다고 발표했다. Associated Press의 기사는 그러한 사업에서 잠재적 이윤을 맛본다고 했다: "천연가스 가격이 현재 28세제곱미터에 약 2.50달러이다. 그러한 가격에서, 1톤에 약 800달러에 팔리고 있는 암모니아 1톤을 만들기 위해 약 82달러의 천연가스가 든다."

현재, 이러한 투자를 이끌고 있는 초과 이윤에 대한 약속이 없다는 데에 주의해야 한다. 에너지 가격은 매우 유동적이고, 그 산업은 미래의 이익에 대한 희망에 수십 억을 내놓는 것에 수반되는 위험에 조심해야 한다. 납세자로 들어가자: 이러한 사업은 국가, 주, 지자체 차원에서 공공자금으로 서명되고 있다. 아이오와 공장의 확장에 대한 보상으로, CF Industries은 주 정부로부터 7000만 달러 이상의 세제혜택 받았고, Woodbury County로부터 공장 건물에 대하여 20년에 걸쳐 1억 6100만 달러의 재산세를 감면받았다고 Sioux City Journal은 보고한다. 루이지애나 역시 기업의 확장에 대해 몇 백만 달러의 세금을 깎아줄 것이다.

Orascom이 건설하는 아이오와의 공장 같은 경우  주 정부의 경제적 재해복구를 돕기로 한 연방정부의 대출프로그램을 통하여 자금지원을 받고 있다 —아이오와의 2008년 홍수. Orascom에게 민간 시장보다 훨씬 낮은 이율을 허락한 대출프로그램은 사실상 보조금이다 —그 기업이 건설에 대한 이자 지급에서 3억 6000만 달러를 절약할 것 같다고 Des Moines Register는 보고했다. 그리고 아이오와주가 그 사업에 허용한 세금감면액은 최고 1억 달러이다.

납세자들은 이러한 사탕과 교환하여 무엇을 얻고 있는가? 내가 볼 때, 별로 없다. 공업형 농업의 인공 질소비료에 대한 지나친 의존이 일련의 환경오염 문제를 일으킨다: 과다한 질소가 하천으로 흘러가고 결국 미시시피강으로 흘러들어 바다 생물을 파괴하는 엄청난 적조의 먹이가 된다; 이산화탄소보다 300배 강력한 온실가스인 아산화질소를 배출한다; 그리고 토양의 유기물을 파괴한다.

그들이 프랙킹의 확산과 그에 대한 강한 규제에 압력을 가하듯이, 우려하는 시민들은 대형 석유회사만큼 강력하고 돈이 많은 경쟁자에게 의지할 수 있다: 대형 농업. 벌써 근본적으로 대형 농업 회사의 로비스트로 활동하는 미국농업협회(Farm Bureau Federation)는 논란의 여지가 있는 에너지원을 지지한다: "농업협회는 수압 분쇄의 사용을 포함하여 석유와 천연가스의 탐사와 생산에 대한 추가적인 방법을 지지한다"고 2012년 10월 정책성명에서 선언했다. 그러나 농업협회와 그 농산업 동맹들은 프랙킹 규제에 대한 싸움에서는 많은 역할을 하지 않고 있다. 비료산업이 값싼 미국의 천연가스에 의존하게 됨으로써, 상황이 변할 듯하다. 보조금을 받는 새로운 대규모 사업으로 질소의 사용을 지지하기보다, 공공정책은 질소가 덜 필요한 농법을 촉진하는 길을 모색할 수 있다. 한 가지 분명한 전략은 다양화이다. 가장 많이 심는 미국의 작물인 옥수수는 다른 작물보다 질소를 많이 필요로 한다. 아이오와 주립대학 Leopold Center의 연구자들이 작성한 2012년의 논문은 전형적인 중서부의 옥수수-콩 작부체계에 질소를 고정시키는 덮개작물에 더하여 "작은 곡물(귀리나 밀 등)"을 추가하여 확장함으로써, 농민들이 질소 수요를 80% 이상 줄일 수 있음을 보여주었다(이에 대해서는 다음을 참고하라 http://blog.daum.net/stonehinge/8726899) (또한 국내에서도 논에서 보리를 재배해 갈아엎는 것으로 수확량이 오른다는 연구결과도 있다 http://blog.daum.net/stonehinge/8725911). 그러한 변화를 촉진하는 정책들에 투자하는 것이 장기적으로 프랙킹 가스에 의존하는 쪽으로 나아가는 화학비료산업에 보조금을 지급하는 것보다 훨씬 현명한 일일 것이다. 

diversifying-corn-soybean-rotations.pdf

출처 http://goo.gl/758Aj

 2013년을 시작하며 많은 사람들이 자신의 건강이나 식단을 개선할 계획을 세울 것이다. 우리는 식량체계를 고치기 위한 더 커다란 계획을 농민, 정책입안자, 소비자라는 더 광범위한 집단의 범위에서 구상해보자 -전 세계의 농지와 회의실과 밥상에서 장기적 영향을 미치는 진정한 변화. 이는 세계에 여전히 굶주리고 있는 10억 명과 과체중과 비만에 시달리는 그 이상의 고통을 해결할 계획이다. 우리는 도구를 가지고 있다 -2013년 그것을 사용하자!

여기 2013년 식량체계를 변화시킬 13가지 해결책이 있다:

1. 도시를 경작하자: 식량생산은 농지나 공장에서만 하는 것이 아니다. 전 세계 약 10억 명의 사람들이 도시에서 식량을 생산한다. 아프리카 최대의 빈민가인 Kibera에서, 농민은 토종 채소의 씨앗을 심어 농촌의 농민들에게 판매하고 있다. 뉴욕의 Bell Book & Candle 식당에서, 소비자들은 로즈마리, 체리토마토, 로메인 상추 및 기타 채소를 식당의 옥상텃밭에서 기른다.

2. 새로운 접근법을 만들자: 오클랜드의 People's Grocery와 시카고의 Fresh Moves는 신선식품을 접할 기회가 부족한 저소득층이 건강한 식품을 선택할 기회를 주고자 휴대전화 식료품점을 만들었다. 감자칩이나 탄산수 대신 그들은 그 지역사회에서 일반적으로 이용하지 못하는 저렴한 유기농산물을 제공한다.

3. 건강한 식품을 먹자: Michael Pollan 작가는 조부모님이 알지 못하는 아무것이나 먹지 말라고 조언한다. 합성보존료나 첨가물이 없는 더 많은 과일과 채소, 완전식을 먹어보자.

4. 요리를 하자: 영국과 미국에서 가사 수업이 감소하며 젊은이들은 기본적인 요리법도 모르게 되었다. 요리사인 Jamie Oliver, Alice Waters, Bill Telepan 씨는 학교에서 아이들에게 건강하고 영양가 풍부한 음식을 어떻게 만드는지 가르치고 있다.

5. 잔치를 열자: Hartman 그룹에 따르면, 미국 성인의 약 절반이 혼자 밥을 먹는다. 가족이나 친구와 함께 밥을 먹으면 지역사회와 대화를 증진시킬 수 있다. 최근의 연구들은 가족과 밥을 먹는 아이들이 그렇지 않은 아이들보다 전형적으로 더 행복하고 안정적이라고 제안한다. 

6. 육식을 피하자: 세계의 약 20억 명이 미량영양분 부족으로 고통을 받고 있다. 세계채소센터(World Vegetable Center)는 아프리카와 아시아의 농민이 건강과 소득을 개선시킬 수 있도록 고부가가치의 영양분이 풍부한 채소를 재배하는 걸 돕는다. 

7. 음식쓰레기를 만들지 말자: 먹을거리의 약 1/3이 버려진다 -농지에서, 운송되면서, 가게에서, 집에서. 그러나 그런 음식쓰레기를 예방하는 쉬운 방법이 있다. Love Food, Hate Waste와 같은 단체에서는 소비자에게 남는 부분의 비율을 조절하고 그걸 요리하는 비결을 알려주는 한편, 볼리비아에서 태양광 건조기를 사용해 음식을 보존하도록 한다. 

8. 청소년을 참여시키자: 지적이고 경제적으로 자극이 되는 농사는 식량체계와 청소년들에게 매력적인 활동이 될 것이다. 아프리카의 사하라 이남 지역에 걸쳐 휴대전화와 인터넷은 기후와 시장 정보에 농민을 연결하고 있다; 미국에서 Food Corps은 건강한 식생활을 준비시키고자 학생들에게 어떻게 작물을 기르고 요리하는지 가르치고 있다.

9. 노동자를 보호하자: 전 세계의 농업과 식품 노동자들은 더 나은 임금과 노동조건을 위해 싸우고 있다. 짐바브웨에서, 일반적 농업, 플랜테이션 노동자연합(General Agricultural and Plantation Workers Union, GAPWUZ)은 학대로부터 노동자들을 보호한다. 미국에서 이모칼리 노동자연합(Coalition of Immokalee Workers)은 플로리다의 토마토 수확 노동자들에게 정당한 임금을 지불하도록 Trader Joe's와 Chipotle를 설득시켰다.

10. 농민의 중요성을 인정하자: 농민은 단순히 농민이 아니라, 사업가이자 토지의 수호자이자 교육자이자 지역사회에서 지식을 공유하는 사람이다. 국제 슬로우푸드는 전 세계에서 농민들과 함께 일하며 그들이 생물다양성과 문화를 지키는 데 중요한 존재임을 인식시키고 있다. 

11. 정부의 역할을 인식시키자: 국가는 모든 사람들이 안전하고, 값싸고 건강한 음식을 먹을 수 있도록 하는 정책을 시행해야 한다.  가나와 브라질에서 전국적인 학교급식프로그램과 지속가능한 농업 생산을 위한 지원을 늘리는 정부의 조치로 굶주리는 사람들의 숫자가 엄청나게 줄었다. 

12. 측정기준을 바꾸자: 정부, 비정부기구, 자금 제공자 들은 영양의 개선과 환경보호보다는 생산량과 수확량의 증가와 개선에만 초점을 맞추어 왔다. 측정기준을 바꾸고, 품질에 초점을 맞추면 공중보건과 환경 및 생활을 개선할 것이다.

13. 망가진 식량체계를 고치자: 농업은 세계에서 가장 급박한 과제 가운데 일부의 해결책이 될 수 있다 -실업 문제를 포함하여, 비만과 기후변화. 이러한 혁신은 더 많은 연구, 더 많은 투자, 궁극적으로 더 많은 자금 지원을 필요로 한다. 

우린 할 수 있다  -함께!

출처 http://goo.gl/RHB7G

eOrganic authors:

This article provides an overview of key concepts in organic fertility management, a review of essential macro and micronutrients, and a listing of nutrient amendments approved for use in organic farming systems. It summarizes strategies used to build and manage fertility on organic farms and provides tips on soil testing and use of nutrient budgets.

Introduction: Soils as the Foundation of Organic Farming
Supplying and Managing Nutrients
Methods Used to Build Soils
Soil Tests and Nutrient Budgets
References and Citations
Further Reading

Introduction: Soils as the Foundation of Organic Farming

Soil health is the foundation of organic farming systems. Fertile soil provides essential nutrients to plants, while supporting a diverse and active biotic community that helps the soil resist environmental degradation. Organic producers face unique challenges in managing soil productivity. Current guidelines on nutrient management for organic farmers are fairly general in nature. Organic farmers rely on intuition and observation, advice from vendors, conventional soil tests, and their own experience to make decisions about the quantity and types of soil amendments to apply. As a result, there is tremendous variability in both the quantities of nutrients applied and the resulting soil fertility status on organically managed farms. Organic farmers seek to "build the soil" or enhance its inherent fertility by using crop rotations, animal and green manures, and cover crops. Crop rotation and tillage practices must provide an appropriate seedbed and pest control while minimizing erosion. Nutrient stocks are maintained through use of natural (non-synthetic) substances and approved synthetic substances listed on the National List of Allowed and Prohibited Substances. This list includes a few approved synthetic fertility inputs, such as elemental sulfur, aquatic plant extracts, liquid fish products, potassium chloride, and sodium nitrate. Many substances on the National List have restrictions, or annotations, on their use, source, or rate of application. Organic farmers are advised to check with their certifying agent before purchasing or applying any synthetic inputs. See Can I Use this Input on My Organic Farm? for more information. In addition, organic growers must document their soil management practices in their organic farming system plan as part of their certification, and keep records of all inputs purchased and applied.

Although the following sections address nutrient management and soil building practices separately, these two apects of management are intimately connected through a system of management. Organic farms that achieve their goals maintain soils and protect the environment while using modest amounts of inputs. Soil tests and simple budgeting tools can help producers maintain balance to achieve success.

Supplying and Managing Nutrients

Although crop nutritional requirements are the same for organic and conventional farms, organic producers apply natural materials and emphasize practices that retain and recycle nutrients within the soil. Sixteen elements are consistently found to be necessary for plants to complete their life cycles (Tables 1 and 2). Additional elements (Table 3) are listed as essential for some species and for animals relying on plants for their nutrition. Carbon, hydrogen, and oxygen, which account for about 95% of plant biomass, are supplied from carbon dioxide and water. The other macronutrients with concentrations greater than 500 micrograms/g plant include nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium (Table 1). Micronutrients taken up in lower abundance are no less neccessary but are not limiting to growth in most situations. Sandy soils with inherenly low nutrient contents are an exception. Micronutrients include iron, zinc, manganese, copper, boron, chlorine, and molybdenum.

Organic farmers use natural materials or, when possible, exploit biological processes to supply needed nutrients to soils. Organic fertilizers are needed in larger quantities than are conventional fertilizers because nutrient concentrations tend to be lower. Organic fertilizers can be more expensive, more bulky and less uniform than conventional counterparts. Before applying anything to your field, you should know what the nutrient analysis of the material is, and be certain the substance is allowed by your certifier. See Can I Use this Input on My Organic Farm? for more information.

One of the simplest things a producer can do is maintain optimal soil pH levels. This is critical as pH influences nutrient solubility, microbial activity, and root growth. High pH favors weathering of minerals an increases the release of cations but reduces the solubilty of salts including carbonates and phospates. Lower pH values favor fungi and high pH favors bacteria. Soil pH can also affect the plant’s ability to take up nutrients directly. At very low pH values (<3), cell membranes are impared and become leaky. For most crops, soil pH levels are optimal between 6.0 and 7.0. Lime can be applied to raise the pH of acidic soils (pH <6) and supply calcium. Alkalinity, which is more difficult to correct, typically requires the use of sulfur and this remedy is typically temporary and more expensive than liming. When adjusting the pH, it is important to know the crop’s pH requirement since optimum pH levels vary by crop.

Nitrogen, is abundant in the environment yet remains the most frequently limiting nutrient for crop production. Organic farms frequently acquire N through nitrogen fixation by legumes. Legume cover crops, green manures, and legume sods can be an excellent sources of N. Vigorous stands of alfalfa, red clover, crimson clover, or hairy vetch can provide between 100-200 lbs N, which should be most, if not all, of the needed N for subsequent crop. About half the N in a green manure is released during decomposition following incorporation. Nitrogen needs are often supplimented by the addition of animal manures, either composted or raw, or other more concentrated sources of nitrogen. These include blood meal, fish emulsion, fish protein, kelp and seaweed, and vegetable meals. Mined nitrates, such as sodium nitrate (NaNO₃, bulldog soda, or Chilean nitrate) may be used, but are limited to a maximum of 20 percent of the crop’s total N requirement. Certifiers frown on use of imported N sources because these share the problems of conventional N sources. Ideally, organic systems will rely on rotations that supply most, if not all, of their N needs.

Phosphorus is another macronutrient that is frequently limiting in sandy soils and/or where systems do not receive additions of animal wastes. Soil P is found in organic and in inorganic forms that are slowly available. Phosphorus availability is sensitive to soil pH and organic matter decay rates. Important sources of P include manure, bone meal, fish and poultry meal, and rock phosphate. High levels of phosphorus are a risk associated with use of manures and some composts.

Potassium is taken up from soil solution and is abundant in soils rich in illitic clays. Mineral weathering can be an important source of K in some soils. Potassium is weakly held on the exchange and so can be depleted where leaching rates are high. Manure additions and plant meals are good sources for K.

Common sources for nutrients are:

• Potassium: manure, alfalfa meal, kelp meal, greensand, wood ash, potassium sulfate, and granite dust
• Sulfur: acid rain, manures
• Calcium: lime, colloidal phosphate, bone meal, gypsum, and wood ashes
• Magnesium: dolomitic lime and langeinite
• Micronutrients: mineral weathering, manure, compost, and liming amendments. The National Organic Program requires that micronutrients not be used as defoliants, herbicides, or dessicants. Micronutrients made from nitrates or chlorides are prohibited. Soil deficiencies must be documented by soil or tissue testing.

Methods Used to Build Soils

Bare fallow

Bare fallow can be used with fallow periods occurring between harvested crops. Fallows commonly occur over the winter in temperate zones or during the dry season in Mediterranean or tropical zones. Use of bare fallow to accumulate water and, at times to control weeds only works to enhance the soil where it concentrates resources enough to increase overall crop productivity. If bare fallow is used, soil erosion must be prevented.

Crop rotation

Crop rotation varies plant species in time and space and is an important strategy for organic farmers. Goals are to keep the soil surface covered with a growing crop for most of the year. Key elements of rotations include the breaking of disease and pest cycles and the inclusion of soil building cover crops or cropped fallow periods. By selecting effective cover crops or perennial crops farmers can maintain or increase soil organic matter content and nutrient availability during periods when cash crops are not grown. For most organic farmers, fertility is based on the rotation and not the amendment.

Cover crops

Cover crops include annual, biennial, or perennial herbaceous plants grown in pure or mixed stands. Annual covers occupy the rotation for part of the year. Perennial crops may be referred to as ley or pasture phase or as a plant-fallow. Cover crops provide soil cover and can help loosen compacted soil through the growth of roots. They enhance soil physical condition and improved water filtration. Legume cover crops provide nitrogen while non-legumes can increase nutrient availability to subsequent crops by taking up nitrogen, phosphorus, and potassium that might otherwise leach or become unavailable to plants.

Diversification

Diversification through rotation and use of covers or lay crops can reduce crop insect pests and diseases, if the cover crops are not alternate hosts. Both covers and perennial lay covers help maintain or increase soil organic matter if they are allowed to grow long enough to produce sufficient biomass. These also help prevent soil erosion caused by both water and wind, and suppress weeds. The management of residues within rotations can be quite sophisticated. For a good example, see the video of a living mulch system for soil fertility featuring Helen Atthowe of BioDesign Farm.

Video 1. Helen Atthowe of BioDesign Farm describes using a living mulch to achieve slow release fertility. Video credit: Alex Stone, Oregon State University, Weed Em and Reap Part 2 Living Mulch System Soil Fertility video.

For more information on rotation and cover crops see the ATTRA publication Overview of Cover Crops and Green Manures and the SARE publication Managing Cover Crops Profitably.

Judicious use of tillage

Tillage is an integral part of many organic systems. Management of soil tilth, organic matter, and fertility is an important aspect of a successful organic farming system. Current organic systems usually require tillage prior to planting and cultivation after planting, especially for corn and soybean production, to control weeds and reduce the incidence of seedling diseases and insect pests. However, tillage destroys the organic matter that is critical in improving soil fertility and soil water-holding capacity. Tillage should be performed when soil moisture is low enough to prevent compaction. Since primary tillage operations are usually performed at least a month before a crop is planted, this requires careful planning and the ability to take advantage of periods of dry weather. No-till agriculture in organic systems is starting to be used in parts of the country. TheRodale Institute has experimented with no-till organic farming using cover crops and tractor-mounted rollers to kill the cover just before planting into it. Ron Morse at Virgnina Tech and Nancy Creamer at North Carolina State University have been adapting these systems for organic vegetable production. Watch Weed Em and Reap Part 2 for more information.

Organic amendments

Organic amendments can be an important resource. Soil fertility and physical condition can be effectively maintained with rotation and appropriate use of organic amendments. Application should be made based on soil testing and/or use of budgets. Manures and composts are the most common organic resources where livestock is in the vicinity. Estimating nutrient contents and availability is neccessary for organic materials. For a farmer's perspective on using organic amendments, watch the video of Steve Pincus of Tipi Produce.

Video 2. Steve Pincus of Tipi Produce in Wisconsin explains how fertility is not a matter of NPK and how bulky organic matter is managed to improve tilth and maintain nutrient supply on his farm. Video credit: John Marlin, Agroecology and Sustainable Agriculture Program, University of Illinois.

Problems associated with nutrient over-addition

There is such a thing as too much of a good thing. Off-site problems caused by over-application of nutrients are better recognized than are problems caused on-site. Conventional agriculture is the primary source of non-point source and P pollution that contributes to myriad environmental and health risks. Problems of over-application in organic systems vary; probably P over-additions are most widespread where manure is readily accessible. This is because the ratio of P to N in manure exceeds that required by the plant. Avoid over-reliance on animal manures, in addition to accumulation of excess phosphorus, concentrations of copper, and zinc, which may accumulate in soils. Over-addition of N, particularly in readily available forms, is a common problem. Over-addition of N and P in organic systems can occur in situations where leaching is restricted (eg: in greenhouses) or after N rich cover crops or manures are applied. The notion that N surplus promotes microbial activity and works against organic matter storage and suppresses plant-microbe associations is finally being accepted as an additional downside of over-fertilization. Excess nutrients can also increase plant susceptibility to pathogens and arthropod pests and can also lead to increased weed competition. Tendency toward nutrient leaching and ability to hold and retain nutrients varies with soils and climatic conditions. Texture and CEC are related to this, with nutrient storage capacity increasing with soil clay and silt contents and cation exchange capacities.

Soil Tests and Nutrient Budgeting

To manage nutrients effectively you can use soil testing and nutrient budgeting. Soil tests are used by organic farmers for several reasons:

1. to ensure that pH and nutrient levels and proportions are in appropriate ranges;
2. to justify the application of micronutrients and other approved fertilizers to a certifier, or to comply with other certification requirements;
3. to identify soil nutrients in excess, so soil and fertility management strategies can be manipulated to a) reduce levels of excess nutrients over time, or b) mitigate the impacts of the excess nutrients on crop, soil, and environmental quality; and/or
4. to track trends in nutrient content, pH, and soil organic matter content over time to ensure soil improvement is taking place.

The National Organic Program regulations require that micronutrients and other fertilizers be applied only when soil or tissue tests indicate a deficiency. Because of this language, some certifiers may require soil and possibly other tests. Contact your certifier for its testing requirements. See the related article Organic Certification of Vegetable Operations.

Frequency of soil testing will depend on your purpose in testing and your situation. To track trends in macronutrients, pH and soil organic matter content, testing once every two or three years, or at a specific point in your rotation cycle, may be sufficient. However, if you are just starting to manage your soil’s fertility with organic practices, or adopting new soil or nutrient management practices, you might want to test more frequently.

Timing of testing will also depend on the purpose of the test. To determine nutrient status of your soil for the upcoming season, test your soil in early spring. To test contents of nutrients with potential to leach over the winter, test in late summer.

A typical soil test evaluates your soil’s pH, CEC, and content and proportion of macronutrients—calcium, magnesium, potassium, phosphorus, and sulfur—which are required by plants in relatively large quantities. Soil organic matter content may not be a routine test, but can be requested. Soils can also be tested for micronutrients (nutrients required by plants at relatively small quantities).

Soil testing laboratories use different soil testing methods that may generate different results. It is important to understand the methods used to generate your test results and use interpretation information that corresponds to that testing method. In addition, using the same testing laboratory for all your testing over time will allow you to compare your test results from year to year and track trends. A soil test is only as good as the soil sample it evaluated. It is important to take a representative sample of the field and the soil volume the crop plant roots will explore to obtain nutrients.

References and Citations

• Clark, A. 2007. Managing cover crops profitably. 3rd ed. Sustainable Agriculture Network Handbook Series Book 2. National Agricultural Laboratory, Beltsville, MD. (Available online at: http://www.sare.org/Learning-Center/Books/Managing-Cover-Crops-Profitably-3rd-Edition) (verified 10 March 2010).
• Bellows, B. 2005. Soil management: National Organic Program regulations [Online]. ATTRA Publication #IP270/272. National Sustainable Agriculture Information Service. Available at: http://attra.ncat.org/attra-pub/organic_soil.html  (verified 10 March 2010).
• Crozier, C., K. Baldwin, and D. Howle. Organic soil fertility management [Online].Organic field crop production and marketing in North Carolina. North Carolina State University, Raleigh. Available at:http://www.organicgrains.ncsu.edu/production/soilfertility.htm (verified 10 March 2010).
• Marlin, J. 2008. More than NPK: Tipi Produce's Soil Fertility Strategy [Online video]. Agroecology and Sustainable Agriculture Program, University of Illinois, Urbana. Available at: http://www.vimeo.com/2312395 (verified 10 March 2010).
• Martens, K., and M. Martens. 2004. What can I use to boost my soil fertility? [Online]. New Farm, Rodale Institute. Available at:http://newfarm.rodaleinstitute.org/columns/Martens/2004/0804/soilfertili... (verified 10 March 2010).
• Parnes, R. 1990. Fertile soil: A growers guide to organic and inorganic fertilizers. Ag Access, Davis, CA.
• Sullivan, P. 2003. Overview of cover crops and green manures [Online]. ATTRA Publication #IP024. National Sustainable Agriculture Information Service. Available at:http://attra.ncat.org/new_pubs/attra-pub/covercrop.html (verified 10 March 2010).
• The no-till revolution [Online]. The new farm. Rodale Institute, Kutztown, PA. Available at: http://www.rodaleinstitute.org/no-till_revolution (verified 10 March 2010).
• United States Department of Agriculture. 2000. National organic program: Final rule. Codified at 7 C.F.R., part 205. (Available online at:http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=5a8dc602e6a7f29...) (verified 10 March 2010).
• VanTine, M., and S. Verlinden. 2003. Maintaining soil fertility under an organic management system. West Virginia University Extension Service, Morgantown. (Available online at: http://www.wvu.edu/~Agexten/farmman2/organic/soilfert.pdf) (verified 10 March 2010).

Further Reading

• Agricultural Marketing Service—National Organic Program [Online]. United States Department of Agriculture. Available at: http://www.ams.usda.gov/nop/ (verified 10 March 2010).

http://www.extension.org/pages/18565/organic-soil-fertility