Chapters
Urban Farming

Growing trend

URBAN FARMING TAKES OFF AS ASIAN CITIES AIM TO CHANGE THEIR FOOD SYSTEMS THROUGH INNOVATIVE MEANS
TOMATO PLANTS DISPLAYED AT THE PASONA O2, TOKYO’S STATE-OF-THE-ART UNDERGROUND FARM. RICE PLANTS, ROSES AND VEGETABLES LIKE TOMATOES AND PUMPKINS ARE VEGETATED IN OTHER FARMING ROOMS WITH ACCORDINGLY ADJUSTED TEMPERATURE, HUMIDITY AND LIGHT. AFP PHOTO/KAZUHIRO NOGI.

By KARL WILSON in Sydney, January 2016.

The idea of growing fruit trees on the top of buildings, or producing fruit and vegetables inside multistory buildings using artificial light, might have been viewed as a fanciful idea once — but not anymore. From Beijing to Sydney and Tokyo to Singapore, urban farming is becoming an integral part of the urban landscape, not only in Asia but throughout the world.

Chris Williams, lecturer in urban horticulture at the University of Melbourne’s Burnley campus, said urban farming, in all its forms, is the new reality in a world where over half the population is now urbanized. That figure is expected to rise to 70 percent by the middle of this century, according to United Nations data. Williams said rapid urbanization has pushed market gardens that once surrounded our cities and towns further out or simply covered them under concrete and asphalt. Today, urban farming is the buzzword for urban planners, whether it is in the industrialized or developing world.

There is a huge difference between urban agriculture in developing countries and industrialized countries.

In cities like Manila, Bangkok and Jakarta, people grow vegetables on any land they can find for day-to-day survival. Meanwhile, in Tokyo it is high-tech vertical farming on a massive commercial scale.

Williams said urban farming, however, should be put into perspective. “There is a huge difference between urban agriculture in developing countries and what industrialized countries are doing,” he told China Daily Asia Weekly. He said that in cities like Phnom Penh in Cambodia and Ho Chi Minh City in Vietnam, urban agriculture is a question of survival for the poor. “In Singapore, it is a question of national food security.” He said the cities of the future will be a “patchwork” incorporating urban farming “and all the new technology that comes with it”.

CITIES TURNING GREEN

In Milan, Italy, on Oct 20, 2015, mayors from more than 100 cities from around the world, among them many from Asia, met to sign a new urban food policy pact to better coordinate their food systems and urban agriculture.

Tim Lang, professor of food policy at City University London and one of the world’s leading experts on the subject, said the Milan Urban Food Policy Pact “signals the return of city regions as powerful voices in modern food policy”.

Sala-delle-Cariatidi-2
MUFPP signing ceremony at the Sala delle Cariatidi, Palazzo Reale, Milan, Italy, October 2015.

“Many have been auditing how they are fed,” he wrote in a recent research paper. “They now recognize their food systems are in a delicate state even when the surface looks fine.

“Health and environmental impacts are high. Geopolitics are tricky. Aspirations for cheap food have become hard-wired into consumer expectations. Waste is rampant and governments bow too much to giant food companies selling sugary, fatty, ultra-processed food.” Almost one-third of all agricultural output in Japan is generated by urban agriculture and urban farmers account for 25 percent of the country’s farming households, according to a report by Japan-based United Nations University.

In Tokyo, one of the largest and most congested cities in the world, among the intricate networks of railways, roads, buildings and power wires, local agriculture produces enough vegetables to potentially feed almost 700,000 city dwellers. It is also home to the world’s biggest indoor farm, which covers 25,000 square feet. The farm produces 10,000 heads of lettuce a day — 100 times more per square foot than traditional methods. It uses 40 percent less power and 99 percent less water than outside fields, according to WebUrbanist, an online magazine featuring urban architecture.

Similar vertical farms are being developed for Hong Kong, Russia and the Chinese mainland.

With 70 percent of China expected to become urbanized by 2030, according to UN data, farming land is fast disappearing to the developers. Throughout China, cities have been encouraging the development of urban farming as a way of bringing food production closer to consumers and reducing its environmental footprint. Beijing was one of the early pioneers for integrating urban agriculture into its strategic development plans.

Beijing has created five zones that govern the type of agro-parks in the city.

Recognizing the importance of urban agriculture to sustainable urban development, Beijing’s municipal government has supported the development of “agro-parks”, which not only produce food but also attract tourism and are used as educational tools, according to Chinadialogue, a website devoted to climate change and the environment.

“Beijing has created five zones that govern the type of agro-parks in the city,” the site said. The “inner urban core” focuses on gardening, landscaping, and exhibition. The “inner suburban plain” specializes in recreational agriculture, which attracts tourism, and precision agriculture, which utilizes smart technologies such as moisture monitoring for automatic irrigation. The “outer suburban plain” emphasizes large-scale, modern agricultural production and processing. The “mountainous” zone is devoted to special fruit and ecologic protection. And finally, the “regional cooperation” zone helps to bolster food security by facilitating relationships with nearby cooperatives and assists to ensure the quality of imports, according to the website.

In South Korea, interest in city farming has increased in Seoul after the incumbent mayor, Park Won-soon, came to power in 2011. Park declared 2012 as the start of an urban farming era and unveiled a plan to secure enough farming space in the congested capital.

According to the local government, the number of city farmers in Seoul surged from 287,000 in 2011 to 440,000 in 2012. The total area of land for urban farms in the city grew from 29.1 hectares in 2011 to 84.2 hectares in 2012.

In Singapore, urban farming has become an issue of national security while in Bangkok, Thailand, it is a cheap, convenient way to help feed the poor.

The challenge facing governments will be to find sustainable ways of providing enough food to feed the urban masses.

The situation is particularly acute in Asia, where cities have grown at a faster rate than any other region in the world, according to the Food and Agriculture Organization (FAO).

The UN body said that Asia has urbanized at unprecedented speed during the past 20 years and feeding its mushrooming urban population will be one of the biggest challenges facing urban planners in the 21st century.

According to Hiroyuki Konuma, the FAO’s assistant director-general and regional representative for Asia and the Pacific, 13 of the 20 most populated urban areas in the world are now in Asia.  “Asia is urbanizing at unprecedented speed,” he told a conference on urban farming in Bangkok in 2013.

Though still predominantly rural, this upward trend is expected to continue for many years to come. In this decade alone, it is anticipated that two-thirds of the growth in the world’s cities will occur in Asia, raising its urban population by another 411 million, Konuma said. “Migration, primarily rural to urban, is a key driver of this growth. However, together with natural growth, reclassification of rural areas is also an important contributor: Every year millions of people become city dwellers by this way even without movement, as their communities are transformed into cities because of rapid urbanization.”

Nicholas Williams, urban ecologist and associate professor at the University of Melbourne, said: “It is the story of urbanization.”

Throughout history, market gardens existed around towns and cities to feed the urban population, he noted. “What we are seeing today, however, is rapid urban growth on a scale not seen before and all that productive land disappearing to roads, rail and housing.” Urban farming is not a new concept, he said. But it has taken off in many cities on a larger scale in recent years.

Williams cited Singapore as an example where food security along with water are seen as national priorities. South Korea is also a supporter of the concept.

“In the South Korean city of Incheon, entire urban blocks have been given over to urban farming. Not only do they provide food but a meeting place, especially for older Koreans.”

On the fringes of the global climate change summit in Paris in December, many of the world’s city mayors met on the sidelines to promote the Milan Urban Food Policy Pact.

The global food system is both victim and perpetrator of climate change. Food production and consumption contribute up to 30 percent of the total greenhouse gas (GHG) emissions and the impact of climate change on food security could be dramatic.

In a statement, the mayors said many cities are already adopting climate-smart strategies.

However, the large-scale shift of the global food system toward more sustainable production and consumption patterns has yet to begin. “If we continue to manage the food system under a ‘business as usual’ approach, the food sector is very likely to become the main contributor of GHG emissions within 20 years. “To lower the impact of agriculture on climate change, action on consumption, logistics and food waste is now crucial.” The mayors said the metropolises of the world will play an increasingly leading political and economic role and acknowledged that the challenges ahead are complex.

“Cities will have to adopt a co-benefit approach: Ensure the right to a healthy nutrition to all people, without jeopardizing the future of the planet.

“As a matter of fact, cities and citizens have the power to shape the demand of food by shifting diets and public purchasing policies towards greener and healthier paths,” they added.

Sprouting imaginative solutions LAND-SCARCE SINGAPORE LEADS THE WAY IN FINDING ANSWERS TO PROTECT AGAINST VOLATILITY IN FOOD SUPPLY

AN ARTIST IMPRESSION OF A RETIREMENT HOME INCORPORATING URBAN FARMING AS ENVISAGED BY SINGAPORE-BASED ARCHITECTURAL AND DESIGN CONSULTANCY SPARK. DESIGNED TO GIVE THE ELDERLY A NEW LEASE OF ACTIVE LIFE AND ACCESS TO FRESH FOOD WHILE PROMOTING COMMUNITY BONDING BY HELPING NEIGHBORS TO KNOW ONE ANOTHER, THESE FARMS TYPICALLY RANGE FROM A FEW HUNDRED TO A FEW THOUSAND SQUARE FEET. PROVIDED TO CHINA DAILY ASIA WEEKLY.

By KARL WILSON in Sydney

As many countries in Asia grapple with a graying population, Singapore-based architectural and design consultancy Spark has come up with a solution which could revolutionize the way retirement villages are built. Rather than just building a sterile retirement village, why not incorporate the development in and around an urban farm?

The idea of urban farming is not new, but for the elderly it is seen as a way of giving them a fresh lease of life with active work outdoors and access to a daily supply of naturally grown fresh fruit and vegetables. A few years ago, architects at Spark came up with Home Farm, a concept for the “next generation of retirement living” in Singapore, said senior architect Yun Wai Wing. “The concept is simple — combine apartments and facilities with vertical urban farming,” he told China Daily Asia Weekly. “Seniors live in a high-density garden environment created by a vegetable farm, where they may even find employment.”

Home Farm is envisioned as an environment that encourages an active lifestyle and social encounters — one that nurtures residents and inspires the curiosity of members of the wider community. The concept has gained a great deal of interest not only in Singapore but throughout Asia, according to Spark. In November, the company announced it will develop the Home Farm concept on a 65,000-square-meter site just outside the Malaysian capital, Kuala Lumpur. When completed in 2018, it will comprise 800 units in an eco-friendly environment complete with terrace gardens for growing vegetables and fruit.

“One of the aims of our research has been to generate a discussion here in Singapore about ways in which we can merge senior housing with urban farming,” said Yun. Spark’s research, which focused on Singapore, examined how the city-state might support a rapidly aging society, and how it might enhance its food security.

Singapore is already experiencing a substantial demographic shift. By 2030 it is estimated that one in five Singaporeans will be aged 65 years and over, up from 6 percent in 1990. “The growing number of seniors in Singapore will place demands on social, economic and infrastructure systems,” Yun said. “Singapore has embraced urban farming as a buffer for potential food shortages.”

He said securing reliable food supplies for growing city populations has become an increasing problem for many Asian governments and city planners. This has become an acute problem for Singapore, a small and fully urbanized city-state without a hinterland.

In 1970, some 25 percent of the island (of Singapore) was used for agriculture. Today, less than 1 percent is farmed as concrete, steel and glass cover areas once used for agriculture.

In 1970, some 25 percent of the island was used for agriculture. Today, less than 1 percent is farmed as concrete, steel and glass cover areas once used for agriculture. As a consequence, more than 90 percent of Singapore’s food consumption is now met by imports from more than 30 countries. This dependency on the external world makes the country highly vulnerable to turbulence in food supply and prices. The only way out of this problem is to maximize the use of land for food production.

For the island of Singapore, where real estate is at a premium and the land rates are exceptionally high, the only viable option is to go vertical to make the island more self-sufficient in food.

Local entrepreneur Jack Ng has developed one of the world’s first commercial vertical farms. The soil-based farm produces 1 ton of vegetables every second day and is five to 10 times more productive than a regular farm, according to a spokesperson for his company, Sky Greens. “Jack wanted to design a vertical farming solution for vegetable cultivation after a successful career and business in the building and construction industry,” the company said. “Using his knowledge and expertise garnered over 30 years of engineering experience in building structures for people, Jack creatively developed a ‘building’ for vegetables for land-scarce Singapore.”

Sky Greens added that besides high productivity in the use of land, the hydraulic-powered design is also environmentally friendly and utilizes low energy and labor resources. “The prototype was launched in 2011 as a collaborative effort with the Agri-Food and Veterinary Authority of Singapore. In 2012, a commercial-scale farm facility was constructed and went into full operation.” Sky Greens has set up a pilot project in South China’s Hainan province, as well as in the Thai capital, Bangkok. “We are currently in talks with multiple parties to implement projects in other cities in China, Malaysia and the United States,” the company added.

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Throughout Singapore, fruit and vegetable gardens are flourishing. Over the last two to three years, more than 80 plots with fruits, herbs and vegetables have sprung up — not only in private and public housing estates, but also in eateries, malls, schools and offices — according to a report in The Straits Timesnewspaper. Companies that help build and maintain these urban farms, which typically range from a few hundred to a few thousand square feet, report a growing interest, the paper said.

People want to grow their own food for various reasons, said former aerospace engineer James Lam, 55, who founded UGrowGardens in Singapore in 2013. He told the paper: “Chefs and homeowners want fresh produce for their kitchens. Companies use the gardens to help their staff relieve stress. Schools use them as a tool to teach teamwork or as part of community service, when they get their students to take the harvests to the poor.” Lam added that such gardens are also a good way to promote community bonding and for neighbors to get to know one another.

Singapore – along with many other cities around the world – sees urban farming as a way of building a buffer against sudden disruptions to the global food supply chain whether it be through price or environmental problems such as droughts and floods.

Some property developers are also beginning to see the value of turning their ornamental rooftop space into a productive food garden, said Bjorn Low, 34, who founded Edible Garden City with former landscape designer Robert Pearce, 38, in 2012.

“Instead of paying a landscape firm to maintain an ornamental garden, they pay us to maintain a food garden and in the process, they can also use the space to conduct value-added events on food growing for their tenants,” Low told The Straits Times.

Singapore — along with many other cities around the world — sees urban farming as a way of building a buffer against sudden disruptions to the global food supply chain, whether it be through price or environmental problems such as droughts and floods.

A study recently warned that the world would face a dire food shortage by 2050, as there may not be enough resources to sustain the projected population of 9 billion people.

Local produce taking root Down Under CITIES ARE TAPPING INTO THE BENEFITS OF FOOD GROWN IN COMMUNITY GARDENS AND URBAN FARMS TO BOOST NUTRITION LEVELS

CUBA HAS BEEN REGULARLY CITED AS AN EXAMPLE OF THE SUCCESS OF URBAN AGRICULTURE IN ADDRESSING FOOD INSECURITY AND INCREASING NUTRITION LEVELS. HERE, A MAN WORKS IN A PATCH OF LAND IN HAVANA. AFP PHOTO/ADALBERTO ROQUE

By KARL WILSON in Sydney

Ask most city dwellers in Australia where their fruit and vegetables come from and they will probably say the supermarket.

Urbanization has not only changed the way we live, it has also changed the way we eat and what we eat.

Urbanization has not only changed the way we live, it has also changed the way we eat and what we eat. It was not that long ago when most urban Australians lived in big houses on quarter-acre blocks — around 1,000 square meters — and grew their own fruit and vegetables.

Today, family homes in older established suburbs are being torn down to make way for blocks of flats while market gardens give way to new suburbs as the urban sprawl expands.

It has been estimated that 90 percent of Australia’s 25 million people now live in cities and towns. Modern transportation and technology means fruit and vegetables can be transported from anywhere in Australia straight to the supermarket shelves. Outside the urban centers, technology has become the new market garden, where hydroponics and artificial lighting are being used to mass produce food.

The last few decades, however, have seen a significant shift back to locally grown produce. Local communities are now taking the initiative and setting up urban farms. Phil McManus, professor of urban and environmental geography with the University of Sydney, said there is a move back by people to grow their own food. “You go to cities like London and in many parts of the city you have garden allotments,” he said.

“In Australian cities we had the big backyards. But these are being swallowed up by urbanization. Then you have the supermarkets, fast food and people became detached from the land.” But he added that in cities around Australia, people are realizing the benefit of growing their own food. “Around Melbourne, Brisbane, Perth and Sydney you will find entire communities involved in growing their own fruit and vegetables … good nutritional food and food which is affordable.”

The Sydney City Council has its own community gardens policy which it says aims “to nurture and grow community gardens” throughout the city. Already the city has 19 community gardens growing a variety food crops from herbs, vegetables and citrus trees to ‘bush tucker’ (native food) plants.

SUSTAINABLE SOLUTIONS

“The gardens are in the city’s parks, abandoned housing land, strata roof tops, footpath verges and church land,” a spokesperson for the Sydney City Council told China Daily Asia Weekly. Native beehives have also been added to community gardens to increase local biodiversity.

“Community gardens are important places to improve community awareness about food and how to grow healthy and tasty food,” the spokesperson said. “Apart from educating people about the nutritional value of food, the gardens contribute to the sustainability of our city.” Sydney recently opened its first working urban farm which will eventually provide farmers’ markets with fresh, locally produced fruit and vegetables.

Australian gardening personality Costa Georgiadis described the farm as “one of the best developments to happen in Sydney in decades”.

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Sydney’s Lord Mayor Clover Moore waters plants at the city’s first urban farm which opened recently. It will will eventually provide farmers’ markets with fresh, locally produced fruit and vegetables. PHOTO PROVIDED TO CHINA DAILY ASIA WEEKLY.

“This farm will be a legacy that will help reconnect people with local and seasonal food,” he said in a statement. “It will become a well-loved place to understand how to grow food, cook it, preserve it and then share it in the heart of a thriving community. I’m on board this tractor for the long haul.”

Sydney’s Lord Mayor Clover Moore said the inner-city farm would give residents the chance to learn about country life and would cater for dozens of educational, community and cultural activities.

“Sydney is one of the few Australian cities without a city farm, yet there’s a staggering amount of community support for one — 95 percent of people who made submissions during our feasibility study said they wanted a city farm,” Moore said.

“We’ve worked closely with the community to develop a place that offers inner-city residents a taste of life on a farm, a place to forge new friendships and the opportunity to learn more about how food is produced.

“With more people than ever living in the city and choosing to raise families here, the city farm will be an important place for people to see where their food comes from — as well as the chance to grow their own.”

One of the first urban farms in the country was Perth City Farm in Western Australia, which started in 1994 on the site of a former scrap metal and battery recycling plant. Once the 5,200 sq m site was cleaned up and declared safe to grow produce, it became an icon for environmental sustainability.

In the 1980s, a 4-hectare site was handed over to the East Brunswick community in Melbourne which became known as the CERES Community Environment Park, or Centre for Education and Research in Environmental Strategies. Apart from farming, the center is an educational facility that teaches water recycling and how to grow organic food, among other things. Its annual turnover is A$9 million ($6.4 million), with 90 percent of that self-generated, and only a small fraction funded through grants.

Recognizing the importance of urban agriculture, the Queensland state government has increased access to land in the southeast corner of the state and in urban areas for the growing of fresh fruit and vegetables. In its 2009-2031 regional plan for South East Queensland, the government said it recognized the importance of providing space for fresh food markets and community gardens and conserving existing agricultural land for food production.

The southeast of Queensland, which includes the cities of Brisbane and the Gold Coast, is one of the fastest-growing urban centers in Australia. The government says that by providing space for urban agriculture such as community gardens it enables access to fresh, high-quality and seasonal local produce. At the same time, the government recognizes the link between better access to fresh produce, and improvements in diets; a link that contributes to reducing the levels of obesity and poor health.

ENHANCING FOOD SECURITY

Haweya Ismail, a research analyst with the Global Food and Water Crises Research Programme, said that Australia produces enough food to feed 60 million people, yet economic barriers leave an estimated 2 million Australians dependent on food relief annually. The program is part of the Western Australia-based research organization Future Directions International.

Ismail said that to enhance food security, efforts need to be focused on overcoming the increasingly volatile food prices that are expected to occur as a result of increased production and energy costs and the effects of climate change.

Urban agriculture has assisted communities in both developed and developing nations to cope with food insecurity, by ensuring local availability of nutritional and affordable food.

“There is a strong consensus amongst academics and policymakers that urban agriculture is a viable means of increasing domestic food security,” she noted in a paper. “Urban agriculture has assisted communities in both developed and developing nations to cope with food insecurity, by ensuring local availability of nutritional and affordable food.”

Cuba has been regularly cited as an example of the success of urban agriculture in addressing food insecurity and increasing nutrition levels. The collapse of the Soviet Union in 1989, and the subsequent reduction in oil and commodity imports, left the nation facing a food crisis. Higher food prices, a decline in rural farming productivity and increased migration to urban areas caused significant food scarcity.

“Urban agriculture became an essential source of food and nutrition within these communities and the Cuban government created policies to support urban-farming initiatives,” Ismail explained. “As a result, communities enjoyed improved nutritional and health outcomes, increased community connectedness and an improved knowledge and appreciation of food production.” She said the Cuban example highlights the “intrinsic value” of urban agriculture as a tool to increase food literacy and healthy food consumption, through active community participation in food production.

“Policymakers need to acknowledge the value of urban agriculture in providing opportunities to promote nutritional education, and support strategies which leverage on existing and new urban farming initiatives to deliver educational programs that promote healthy eating habits.”

Toward a sustainable farming model ANCIENT METHODS AND MODERN BIOTECHNOLOGY HOLD THE KEY TO FEEDING THE GROWING GLOBAL POPULATION

A FARMER USES A TRACTOR TO PLOUGH A FIELD IN A VILLAGE IN BENGBU, EAST CHINA’S ANHUI PROVINCE. CHINESE AGRICULTURE FACES MAJOR ENVIRONMENTAL CHALLENGES, INCLUDING SOIL EROSION, SOIL POLLUTION, WATER SCARCITY AND LOSS OF AGRICULTURAL BIODIVERSITY. AFP.

By COLIN OSBORNEDUNCAN CAMERON and MARK SINCLAIR

China, despite only having some 9 percent of the world’s farming lands — as farming land per capita here is less than 40 percent of the global average — is a net exporter of food and successfully feeds 21 percent of the world’s population through intensive agriculture. But this tremendous achievement comes at a cost.

Chinese agriculture, like intensive agricultural systems in many parts of the world, faces major environmental challenges. Soil erosion, soil pollution, water scarcity and loss of agricultural biodiversity are widely reported.

Intensive agricultural practices around the world are currently unsustainable.

Intensive agricultural practices around the world are currently unsustainable. Under this system, crop yields are maintained through heavy fertilizer applications, which are unsustainable because these require high energy inputs to supply inorganic nitrogen (this process consumes 5 percent of the world’s natural gas production and 2 percent of the world’s annual energy supply).

It also depends on the mining of non-renewable rock phosphorus, diminishing stocks of which will become increasingly difficult to extract in the coming decades as the easiest-to-access ore with high phosphorus content has already been mined. Further, it allows nutrients to wash out and pollute fresh and coastal waters, causing algal blooms and lethal oxygen depletion, as well as dispersing nutrients in the ocean.

Despite these high environmental costs of conventional intensive agriculture, and the widespread application of crop-breeding programs, we have been unable to improve the yields of several major crops, which have stagnated in the past 15 years.

China’s rapid industrialization has given rise to concerns over soil pollution. An official report by the country’s Ministry of Environmental Protection and the Ministry of Land and Resources found pollutants in 20 percent of arable land, exceeding national standards. Such land can be rehabilitated but this requires taking that land out of food production, with possible consequences for food security. Other threats come from soil erosion: A government report published in 2008 estimated that 100 million Chinese could lose the land they live on within 35 years if soil erosion continued at the current rate.

While experts cited farming and forestry as the main causes, contributing to over a third of the area affected, the research team said erosion was damaging industrial areas and cities as well as remote rural land. Water is an increasing issue in China too — water shortages, water pollution and flooding are all impacting growth and affecting public health and welfare in many parts of the country.

In 2011, China switched from being a predominantly rural society to one in which more than half the population live in cities. At the end of 2014, some 54 percent of the population lived in cities, up from 36 percent in 2000, according to World Bank data.

NEW INTENSIVE MODEL

In a recent paper, the Grantham Centre for Sustainable Futures, a collaboration in the United Kingdom between the University of Sheffield and the Grantham Foundation for the Protection of the Environment, set out a model for a system of intensive agriculture that would address the needs of growing populations and developing economies in a sustainable way.

This model combines the lessons of history with the benefits of modern biotechnology, to redesign intensive agriculture.

Modern varieties of crops used in many intensive agricultural systems have been optimized for a system of high-nutrient artificial inputs and chemical control of pests and diseases. These crops have consequently lost their natural reliance on the microbes in soil which, in native varieties, enable plants to extract complex nutrients from the soil and to defend themselves against natural enemies.

A model that combines the lessons of history with the benefits of modern biotechnology, to redesign intensive agriculture.

Soil is thus becoming a hydroponic system: A physical substrate to support plants, but providing little else. In particular, deep ploughing has caused a decline of soil organic carbon, reducing the soil’s abilities to retain water and supply nutrients, and a loss of structure that allows rapid soil erosion.

As soil is lost rapidly but only replaced over millennia, this represents one of the greatest global threats for agriculture. It is the degraded state of our agricultural soils that appear responsible, at least in part, for the plateauing in yield for many of our crops.

In the 19th century, farmers in the UK had little access to artificial fertilizers, and consequently had to manage the soil well. Soil management combined the application of manures and the rotation of annual crops with grass and nitrogen-fixing legume cover crops which recharged soil carbon and nutrients as well as rebuilding soil’s physical structure.

These conservation-agriculture methods are today practiced in organic agriculture, where the resultant benefits of increased organic matter for soil structure, water-holding abilities, and nutrient availability are well established. However, organic systems do not utilize advances made in agrichemistry inputs, meaning that yields are limited, thus rendering organic agriculture unsustainable in terms of feeding a growing global population.

Historically, good soil management was supplemented by the collection and application of “night soil” (human excrement), a practice that continued into the 20th century. In a historical example of the circular economy, this closed the nutrient loop, recycling organic nitrogen and phosphorus back into soil.

MODERN APPROACH

Additional benefits for soil organic matter are achieved in modern agriculture from the “no-till” method, where direct drilling is used to sow seeds, and cover crops and weeds are removed using herbicides, and ploughing is not needed. This approach reduces the oxidation of soil organic matter, conserving the soil structure.

This echoes China’s traditional farming practices which stretch back some 4,000 years. For most of this time, it used no chemical fertilizers or pesticides, yet supported small-scale intensively managed farms which maximized land productivity.

As with Europe in the 19th century, traditional Chinese practices included legume crops for nitrogen fixation, and the use of diverse crop varieties in rotation. Human, animal and crop wastes were also systematically recycled to maintain soil fertility. Many of these successful Chinese agricultural practices were described by the American agronomist Franklin Hiram King in his book, Farmers of Forty Centuries, published shortly after his death in 1911. He said the key to 4,000 years of land fertility was the practice of “agriculture without waste”, with no use of external inputs.

While the enhanced use of cover crops almost certainly requires an increase in the land area used in agriculture, there is potential for less land to be in active cultivation at any one point in time.

A sustainable model for intensive agriculture could combine the lessons of Chinese and European history with the benefits of modern biotechnology, and is founded on three principles:

– First, managing soil by direct manure application, the rotation of annual and cover crops, and practicing no-till agriculture.
– Second, using biotechnology to wean crops off the artificial world we have created for them, enabling plants to initiate and sustain symbioses with soil microbes.
– Third, this involves the recycling of nutrients from sewage, in a modern example of the circular economy. Inorganic fertilizers could be manufactured from human sewage in biorefineries operating at industrial or local scales.

Enhancing the biological functionality of soils allows it to store more water and nutrients, and support microbial communities that can boost plant health through direct suppression of soil-borne diseases and priming plant immune systems. Of course no one model equally fits all problems, different agricultural scenarios (geography, climate, crop) will benefit from this approach more than others.

Redesigning the agricultural system would not be straightforward but, in doing so, we could reduce our dependence on energy-intensive and non-renewable inorganic fertilizer, reduce fertilizer pollution of watercourses, and create a soil fit for future generations.

Colin Osborne is associate director at the Grantham Centre for Sustainable Futures at the University of Sheffield in the UK. 

Duncan Cameron is professor of plant and soil biology and co-director at the Plant Production and Protection (P3) centre for translational agricultural technologies at the University of Sheffield.

Mark Sinclair is the director of Science and Innovation Partnerships for Energy2050 at the University of Sheffield, on secondment from the UK government’s Foreign & Commonwealth Office Science & Innovation Network.

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