From dust bowl to carbon sink: the potential of conservation agriculture

ID-10049859Two new videos exploring conservation agriculture were recently shared. The first looks back to the US dust bowl in the 1930s that motivated the development of no-till farming and conservation agriculture. The second looking at how conservation agriculture can help in practice and how we can prevent the next dust bowl in the Russian Steppes through sustainable land management strategies.

Changing an Age-Old Practice Helps New Generation of Farmers, is the title of a new video created by the World Bank. Tilling of soil is done to prepare the seed bed, release nutrients and control weeds but tilling can also lead to soil erosion, causing the loss of top soil that degrades farmland and causes sedimentation in waterways. In the lower Mississippi River removal of sediment costs over $100 million each year. In the Great Plains of the US around the 1930s the dust bowl winds eroded top soil from 65 million hectares of land and led to an unprecedented environmental disaster. Soil degradation globally is increasing due to climate change whereby more frequent storms and floods erode vulnerable soils. The disturbance of these soils releases greenhouse gas emissions, contributing to climate change.

Conservation agriculture is proposed as a solution, which comprises no tillage of the soil or minimum disturbance of the soil; the maintenance of crop residue in the field; and crop rotations and species diversity. These practices help to reduce soil erosion, allow recovery of the soil structure, reduce pests and diseases, conserve water and build up nutrient stores. Such practices are also said to be more labour and cost efficient. Breaking the centuries old tradition of tilling the soil is not easy however, and requires the development of new herbicides, new equipment and farmer education. But the benefits conservation agriculture can bring, such as relatively inexpensive climate change adaptation and mitigation and sustainable farms into the future, far outweigh the costs.

How to prevent the next “Global Dust Bowl”? – Ecological and Economic Strategies for Sustainable Land Management in the Russian Steppes: A Potential Solution to Climate Change was produced by Kulunda, an interdisciplinary project on sustainable land management. The Kulunda Steppe in Siberia close to the border with Kazakhstan has dry continental climate conditions. In the 1950s about 420,000km2 of natural grassland were converted to farming. In recent decades crop yields have been continually declining as a result of low soil fertility and carbon, wind erosion and drought, and today some 50% of these lands are degraded. Because of the arid climate the soil neither stores water nor nutrients well and conventional agricultural methods are failing leading to the out-migration of young people. [Read more…]

New books for 2014

ID-10031308Here we bring you some of the latest books addressing topics such as food policy, global food security, African political change, gender mainstreaming and permaculture.

Frontiers in Food Policy: Perspectives on Sub-Saharan Africa edited by Walter Falcon and Rosamond Naylor.

This volume is a compilation of papers from the Center on Food Security and the Environment’s Global Food Policy and Food Security Symposium series discussing such topics as food price volatility, agricultural R&D and climate change.

Crop yields and global food security: will yield increase continue to feed the world? By Tony Fischer, Derek Byerlee and Greg Edmeades.

This is an reference book discusses the opportunities for crop yield increase to feed the world to 2050. Aimed at agricultural scientists and economists, decision-makers in the food production industry, concerned citizens and tertiary students, it includes information on crop area and yield change for wheat, rice, maize, soybean and 20 other important crops; a detailed tour of the key breadbasket regions of the world; a discussion on ways for achieving the target yields without a substantial increase in cultivated lands; and implications of further yield increase for resource use, agricultural sustainability and the environment.

Farmageddon: The true cost of cheap meat by Philip Lymbery, Compassion in World Farming

Over three years, the author has travelled the world bearing witness to the hidden cost of cheap meat and the devastating impact of factory farming – on people, animals and our planet. The result – Farmageddon – is a wake-up call, exposing factory farming as one of the most pressing issues of our time; responsible for unparalleled food waste, damage to our health and the countryside, and the biggest cause of animal cruelty on the planet.

Global Food Futures: Feeding the World in 2050 by Brian Gardner

By 2050 the world will be faced with the enormous challenge of feeding 9 billion people despite being affected by climate change, rising energy costs and pressure on food growing land and other major resources. How will the world produce 70% more food by 2050 to feed a projected extra 2.3 billion people? What will be the impact of food shortages and high prices on areas in crisis such as sub-Sahara Africa? Where will future production growth come from? And how do we balance the need for environmental protection with sustainable agricultural production methods. This text presents a scholarly, balanced approach to the contentious area of food production and supply up to 2050 – tackling the global food situation in all its totality, from agricultural production, technological advance, dietary concerns, population changes, income trends, environmental issues, government food and agriculture policy, trade, financial markets, macroeconomics and food security. [Read more…]

The value of soil

ID-10064167“For all things come from earth, and all things end by becoming earth.” Xenophanes, 580 B.C. You could, in reading this quote, be mistaken in thinking that the soil is a regenerating, renewable resource. Soil is formed from slowly decomposing rocks, sediment and organic matter. This process is so slow in fact that it takes 2,000 years to build 10cm of topsoil, such an unhurried rate of growth that soil should be thought of as finite, non-renewable and a resource that needs to be protected.

Healthy soils provide a variety of ecosystem services such as nutrient cycling, water regulation, flood protection, habitats for biodiversity and food production. For approximately 1 to 1.5 billion people in the world land degradation is reducing some of these services, negatively impacting their quality of life and livelihoods.

So far we haven’t been doing a very good job of protecting the soil. We overuse and cultivate unsuitable land which leads to land degradation. Soils left bare in conventional farming practices and farming on slopes accelerate soil loss and erosion. Forests and plants protect the soil but every year 13 million hectares of forest are cut down and to date an estimated 75% of the world’s primary forest has been cleared.

In 2011, an estimated 24 billion tonnes of soil were lost, which amounts to some 3.4 tonnes of soil lost per person. The United Nations Food and Agriculture Organisation estimates that one quarter of the world’s 13 billion hectares of land is degraded. In the pursuit of greater yields and profits we have compromised soil health, mining soils for nutrients, over-using fertilizers, creating over 4 billion hectares of man-made deserts and depleting over 8 billion hectares of deep organic soils.

Soils for Life, an Australian project, produced a video for 2012 Global Soil Week, which likens the world’s store of soils to money in a bank account, from which we continually withdraw without paying in.

Only more recently have we begun to explore the costs land degradation imposes on the environment and society.Soil degradation costs every person on the planet $70 each year, totalling $490 billion and this doesn’t include the indirect impacts of poor soils such as reduced water supply and declining crop yields, in turn leading to poverty, food insecurity and conflict, impacts that are only expected to worsen. In Africa two-thirds of crop land is expected to be lost by 2025. One thing is clear: it is not economically viable to carry on using and exploiting soils in the way we do today.

Recently the Economics of Land Degradation (ELD) Initiative produced a video explaining the value of soil. The video explains that degraded soils leave us vulnerable, reducing ecosystem goods and services and resilience. For example degraded soils can’t store as much carbon, contributing to climate change. But soils can also be degraded as a result of changing weather patterns.

Both videos point to sustainable land management as the answer to land degradation and declining soil resources. While acknowledged as being expensive to implement, such practices are more cost effective over the long-term. Through farming methods such as conservation tillage we can rebuild soil stores. Some studies have shown that organic matter can increase by as much as 1,800 pounds per acre per year under long-term no-till production. Sustainable land management practices could, it’s estimated, add additional crop production of 230 billion tonnes each year.

We cannot overlook soil as there is no life without it. There is hope for the future that through sustainable agricultural practices we can reverse current trends of land degradation. But we need a better understanding of the value of soils, the processes that occur in soils and the best way to protect and restore soil reserves. To end with another quote: “We know more about the movement of celestial bodies than about the soil underfoot.” Leonardo DaVinci, circa 1500s.

Plant intelligence

ID-10046055New research has shown that plants may be more intelligent than we think. A recent study conducted by the University of Western Australia, demonstrated that the plant, Mimosa pudica, could learn new behaviour and retain this memory for weeks. Mimosa pudica is a plant that when touched folds inwards, thought to be a reflex in response to predation. But when the plant was dropped several centimetres down repeatedly it quickly learnt, within minutes, that this posed no threat and stopped folding its leaves, a behaviour that persisted when plants were dropped weeks later. When shaken instead of dropped the plant would fold its leaves in response to this new threat. Watch a video of the plant’s response here.

 
Plant intelligence experiments are not new although earlier studies have been met with criticism for being unscientific. The 19773 book, “The Secret Life of Plants,” by Peter Tompkins and Christopher Bird, presented some of these, including experiments claiming plants could effectively read minds. Although much of this work has been discredited, it’s thought by some to have had a negative effect on the momentum of the field of plant intelligence. But this is changing. In 2006, an article in Trends in Plant Science suggested a new field called “plant neurobiology.” Authors of the article explained that some behaviour in plants could not be solely attributed to genetic and biochemical mechanisms but instead plants could sense and respond to a variety of factors: light, water, gravity, temperature, soil structure, nutrients, toxins, microbes, herbivores, chemical signals from other plants.

 
Of course plants don’t actually have brains but they do collect, analyse and integrate knowledge and react in new ways through analogous structures to our neurological system. They also don’t have ears but have been witnessed secreting defensive chemicals in response to hearing caterpillars eating nearby. Plants can also sense objects before coming into contact with them and move away from them. They have systems for sending electrical and chemical signals (such as dopamine or serotonin also found in humans). How these systems work is still largely unknown. And there remains significant disagreement, not least in calling the field plant neurobiology despite plants having no neurons, on the credibility of investigation into plant intelligence. In the 1980s scientists working on plant communication and signalling faced similar scorn. The Mimosa pudica experiment has also received its fair share of criticism with some scientists claiming the plant’s behaviour is more to do with habituation, desensitization or adaptation, talking issue with the use of the words learning, memory and intelligence.

 
So it seems plants can learn they can retain memory and they are conscious of their surroundings. Whether this can be called “intelligence” depends largely on the definition of intelligence but one thing is for sure, the differences between plants and animals is becoming much less clear.

 
More information can be found about plant intelligence and current debates by watching Stefano Mancuso’s TED talk.

 

Scaling Up Sustainable Land and Water Management Practices

ID-100135195Land degradation and declining soil fertility are major threats to agricultural productivity and food production, particularly in the drylands of sub-Saharan Africa, where land management practices, high fertiliser prices and water shortages contribute and exacerbate the problems. The World Resources Institute have previously calculated that to eradicate food insecurity we need to produce 69% more calories between 2006 and 2050, while at the same time protecting the world’s water, climate and ecosystems. A new report by the WRI entitled Improving Land and Water Management, instalment four of their Creating a Sustainable Food Future series, outlines some of the land and water management practices that can mitigate land degradation and increase agricultural output. They highlight four practices that are particularly promising, which along with raising yields and productivity can increase incomes, natural capital and resilience to climate change. These are:

Agroforestry – the integration of trees and shrubs onto farms

Conservation agriculture – the combination of reduced or no tillage, crop rotations and on-farm conservation of crop residues or cover crops

Rainwater harvesting – the use of on-farm systems such as bunds, pits and trenches, to collect rainfall and prevent water loss from soils

Integrated soil fertility management – the incorporation of prudent and targeted use of fertiliser with organic alternatives such as manure, compost, leaf litter, crop residues and phosphate rock

The report provides evidence of the impacts these farming practices can have, for example, the combination of conservation agriculture and crop rotations has resulted in 50% higher yields of maize in Zambia. These practices can be combined with each other as well as with more conventional technologies e.g. microdosing of fertilisers.

Implementing and combining these four techniques at scale will require much coordination between different users of the landscape, warranting an integrated landscape approach that acknowledges and plans for multiple land uses. Adoption of these practices is currently low and the main barriers to successful scaling include poor knowledge dissemination, weak land tenure systems and poor coverage of extension services. The potential of these improved land and water management practices has been calculated: if implemented on some 75 million hectares of cropland, with an expected increase in yields of 50%, farmers would produce 22 million tons more food each year, equating to an extra 615 kilocalories per person per day for 285 million people living in Africa’s drylands. [Read more…]

Soil biodiversity and ecosystem function

SoilIt has long been recognised that organisms living in the soil are important for making nitrogen available to plants and for storing carbon in the soil but a new paper in PNAS by de Vries et al, Soil food web properties explain ecosystem services across European land use systems, investigated the impact of communities of soil organisms on the overall functioning of ecosystems.

The study is the largest of its kind, involving researchers from across Europe, and is the first time whole communities of soil organisms have been investigated. Spanning 60 sites across 4 countries and three types of land uses (intensive wheat rotations, extensive rotation and permanent grassland), the study marks a significant piece of evidence for the importance of soil biodiversity.

Researchers found a strong link between soil biodiversity and the performance of ecosystems, in particular on carbon and nitrogen cycling. Indeed soil biodiversity was a greater predictor of C and N cycling than land use. Intensive wheat rotation was found to reduce soil biodiversity across the food web in all countries. The authors hope that this and other research will lead to the development of sound land management practices that support soil biodiversity, in turn increasing the productivity of land while mitigating climate change.

The study concludes that we require more research into soil food webs and in particularly how they might alter in response to changes in land use and climate change. Soil biodiversity is understudied, perhaps because of its scope, but it is under increasing threat from, for example, urbanisation, climate change, pollution and agriculture. Mapping and conserving soil biodiversity is urgently needed if we are to include their roles in C and N cycling models, which will in turn help us to better understand the likely impacts of climate change.

The importance of seed diversity

ID-100144378 (2)Seeds might be small, inconspicuous things but they hold a great deal of power. For some, seeds mean survival, ritual, life. They are the basis of much of the food we consume. Perhaps because of their power and their value to the planet’s food security, seeds are a controversial topic. The sale of seeds, the modification of seeds and the saving of seeds are all issues which inspire much discourse and disagreement.

The Gaia Foundation produced a video called Seeds of Freedom, which documents the century’s old custom of saving and selecting seeds best adapted to local conditions, cultural preferences, and resilient to environmental constraints. The film highlights the threat that privatisation of the production and sale of seeds poses to these traditional farming practices.

Cycles of seed saving and the maintenance of agricultural biodiversity have been challenged by the introduction of higher-yielding hybrid and introduced crops that can lose their vitality after the first season, thus requiring farmers to purchase new seeds every year. The video paints the leaders of the Green Revolution as seeking power over the seed value chain. And while many would disagree with this, that scientists were developing high-yielding locally adapted crops with the aim of increasing food production and reducing hunger, there is little doubt that agricultural crop biodiversity was lost as the rise of monocultures and heavy chemical use expanded rapidly. In the Philippines, a poster country of the Green Revolution, only 8 rice varieties out of 3,500 are now grown.

Agricultural biodiversity and the wealth of information and traits it contains is particularly important given the global challenges we face, not least climate change. There are crops and crop varieties that can withstand extremes that would decimate many of the crops we regularly eat. Pearl millet for example, a crop grown annually on more than 29 million hectares in the arid and semi-arid tropical regions of Asia, Africa and Latin America, can survive the most hot and hostile Sahelian conditions.  Thus conserving seed diversity both in situ and in seed banks is imperative. A recent blog on Food Tank outlines 15 seed saving initiatives protecting biodiversity for future generations.

For many the concept of saving seeds is firmly entrenched in the ideals of food sovereignty, which is about the right of people to define their own food systems. Few would argue against increasing food production in developing countries and reducing the huge amounts of imports, which can leave poor consumers at the mercy of volatile global food prices. But in the extreme, food sovereignty espouses the restriction of all food trade and corporate involvement which raises a couple of issues.

Firstly agro-ecological methods and traditional farming, while often more resilient than conventional monocultures, have limits to the amount of food they can produce per unit of labour. In Africa, where smallholder farms dominate, maize yields average 1 ton per hectare, compared to Iowa, where farmers have access to the most cutting edge of technologies including GM and get, on average, yields of 11 tons per hectare. The answer is not in transferring an Iowan system of farming to Africa but technology does have the potential to transform productivity and livelihoods. [Read more…]