Dirt to Soil: the societal turnaround that starts in the paddock

What is the latest news from soil experts on regenerative farming and creating resilient pastures?

If you are a dairy farmer struggling with an unproductive paddock, or a consumer who are interested in healthy, life-giving food, then you will benefit from studying this information that is backed by science. This article is about how microbial- and plant diversity can be utilised for increasing fertile soil and abundant biomass quickly, even during a dry season. Some farmers around the world have added cover crops for grazing to their permanent pastures with amazing results.

Yes, the evidence is in: the right set of land management practices has huge potential for providing the abundant green biomass needed for a thriving raw milk from cows industry in Australia. A community of a diverse mixture of plant species has a miraculous way of supporting itself with more resistance to drought, and other benefits…

Gabe Brown regenerative farmer Quote

50’C temperatures have occurred all over Australia since the early 1800s, according to this article. “Australians have been recording temperatures of over 50’C since 1828, right across the country. In 1896 the heat was so bad for weeks that people fled on emergency trains to escape the inland heat. Millions of birds fell from the sky in 1932 due to the savage hot spell. In 1939 outer Sydney reached 122’F or over 50’C…”

The diaries of George Augustus Robinson written in the 1840s describe that the Victorian grasslands had gone for 90 days without rain, and in 37'C temperatures in February the grass was still green and "luxuriant". There were carpets of colourful wildflowers, 300 - 400 different native plant species of visible green colour in all directions and the grasslands were described as a hydrated landscape that didn’t burn easily. How was that possible? Science now show how it was, and is still is possible.

The earth seems to have its own mysterious macro and micro weather cycles that we are not quite privy to, however this time, after we’ve had extreme temperatures and drought, many of our grasslands have lost their resilience completely. What went wrong? Many scientists already know what went wrong and their teachings are helping farmers make the required changes, despite the fact that regenerative farming was one of the top ten most censored news stories of 2018.

In this video, Australian soil scientist Dr. Christine Jones acknowledges what many in the soil health community already know: we have created the drought by the way we farm. She has a doctorate in soil biochemistry and worked in public research and extension before becoming a soil health consultant on the world stage. She says how cropland and pastures are managed is the most effective way to remedy climate change, an approach that isn’t getting the attention it deserves. Christine promotes keeping

the soil covered at all times with diverse plant communities while dramatically reducing dependence on fungicides, pesticides and artificial fertilisers. The answer to healthy working landscapes is not more inputs, or even more rainfall, she contends, it’s understanding and capitalising on the benefits of diverse mixtures of plants working together to draw carbon out of the atmosphere and back down into the soil.

Industrial agriculture with its monocultures, plowing, synthetic fertilisers and other chemicals with antimicrobial properties have disrupted and killed off soil microbes, decimated mycelial (fungal) networks, and removed the soil’s protective, biodiverse armour. Overgrazing the paddocks has led to a significant decrease of plant species as animals eat their favourite plants first. If they are not rotated frequently in a planned grazing system, plant diversity, and then drought-resilience will decline. Over time farmers may not even realise that they have a degraded landscape, learn more here.

Dust storms are becoming more common in Australia, because some soils have not been covered by plants with protective root systems that lend it integrity. Floods are also more common. The topsoil of some Australian farms are now either being blown away by thick dust storms, or washed off farm by moving water. It is urgent that farmers and policy makers look at why it is important to learn to create miracles at ‘paddock level’, as Former Governor General Michael Jeffrey, founder of Soils for Life also advocates.

The 23rd Annual Winter Conference, North America’s premier soil health conference held on the 29th - 30th of January has recently concluded in Wichita, Kansas, USA. No-Till on the Plains is the non-profit educational organisation who hosted it. The conference had more than a handful of speakers, but three of the speakers gave presentations of particular interest, that led to the writing of this article.

Image: The power of diversity: a cover crop for grazing from a paddock on a New Zealand dairy farm. New Zealand has good rainfall, however, incredible biodiversity and abundant green biomass can also be achieved in arid areas as well, as the evidence show. Click to enlarge image.

This article explores some of the latest systems approach realisations around restoring biology and fertility to soil, and growing a large biomass of multi-species forage for livestock to graze on.

It is vital that dairy farmers grasp why it is important to use biological tools…

… like growing a large diversity of plants and microbes in their paddocks, and to rotate the ruminants around those tall grass paddocks. Graziers have been told in the past that they cannot graze tall grass, but now new wisdom is being taught at conferences like these. When graziers grow tall grass, with the help of green cover crops, and let the cattle graze on the top half of the plant by weight, protein and energy are higher and the results speak for themselves. Animals are healthier, they grow better, they produce more milk and have increased fertility.

Desertification of soil is not a new concept as university Professor David Montgomery explains. Even the Greek philosopher Plato 427-347 B.C had figured out the connection between soil degradation, and the longevity of societies and their inability to live off degraded land and still be prosperous. This is an old problem that have been accelerated in recent decades with modern farming equipment that till or plow on

Image: Ceres in mythology is the Roman goddess of the harvest, who presides over grains and the fertility of the earth. Clearly the issue of soil fertility has been coming for a very long time. Ceres, or Demeter as her Greek counterpart is known, is depicted holding a sickle and a harvest of grain. In ancient times soil fertility was ascribed to the workings of the gods. Today we can see ‘the gods’ by looking through a microscope.

large-scale, and the use of chemicals with antimicrobial properties and synthetic fertilisers. Dairy farmers have also grown monocultures of ryegrass in the paddocks, which unfortunately also accelerate desertification. Science show microbiology does not flourish as well in plant monocultures, and this does affect soil fertility.

Fortunately, loss of soil fertility is a problem that can be reversed rather rapidly when the right methods are applied.

Some farmers around the world are building topsoil back so fast, that not even nature can do it in a similar timeframe.

The organic matter and carbon in the soil, brought about due to biology, is the currency, the food and the battery that keeps regenerating systems going.

Soil scientist Dr Christine Jones explains why above ground, plants provide habitant and food for other life. When we eliminate plants, like we do with modern industrial farming, we eliminate both microbial and plant life. The living plants in the soil, as a green cover year round, support the microbes that create fertile soil with high nutrient status and high water-holding capacity. This is why it is so important that grasslands are managed well. In colonial times, Victorian grasslands reportedly had 300 - 400 different plant species, and the soil was soft and hydrated. In the USA, some prairie grassland ecosystems still have 700 - 800 different plant species in it due to good management.

All of these land management practices together make it easier to put the water back into the soil, instead of it sitting on the land, unable to penetrate after rain. A large diversity of plants with their associated soil microbes, create structures in the soil (called soil aggregates) that allow fast water infiltration rates via channels that go towards roots, and keep the water there. Soil carbon, which is the black layer of soil near the roots, is important to keep the water in the soil.

The organic carbon content of soil is the key determinant of water-holding capacity. Organic carbon content of soil is also a key driver of high nutritional value in food. The organic carbon content of the soil is a key driver for farm profit.

Gatherings like No-Till on the Plains provide an opportunity for knowledgable people to share the latest findings, and show it’s important to get a quorum of farmers in society to understand the interconnectedness in nature, so we can begin to restore plant-, animal-, and human health. Consumers are increasingly asking for nutrient-dense foods and farmers will have to learn how to grow it. The benefits of increased biodiversity hold true for both cropland and pasture, although this article focusses more on the cover crops for grazing livestock in the paddock.

Plant species and microbial diversity as extraordinary tipping points for soil fertility and farm profitability

Australian soil scientist, Dr Christine Jones, recently presented some fascinating new information at the annual No-till on the Plains 2019 conference. The title of her presentation is Community Tipping Points: Enhancing plant nutrition, yield and resilience through quorom sensing. Christine is interested in discovering what kind of tipping point is needed, that translates into the kind of amazing resilience seen where some farmers are creating incredible changes in the soils, the biomass and in the animals.

Christine talks about the incredible benefits of growing 27 different kind of plant species in one paddock. She asks: why would farmers not want to farm this way, when soil fertility can be restored rather quickly? She also considers 12 plant species to be the minimum kind of diversity needed in a paddock. More dairy farmers are taking their existing permanent pastures and adding a large variety of cover crop plants for grazing to them.

Plants, animals and humans are embedded in a microbial world.

Christine talks about how the genes in plants, animals and humans can be activated (switched on or off) by microbes. She also describes an engineering feat: microbes can’t communicate any other way other than chemically, however they get themselves so well organised, and via chemical signatures build structure around plant roots that achieve all sorts of extraordinary biochemical transformations. They ensure that everyone in the system’s needs are met, and they restore atmospheric carbon into the soil.

Sufficient carbon is necessary for the full expression of a plant’s genetic potential.

Evidence of healthy soil includes a rich, dark colour, high organic matter, an aggregated structure and complex mycelial networks of filaments colonising around plant roots, which enable increased absorption of water and nutrients.

Also described, is the importance of realising how interdependent communities of organisms are. Plants, animals and humans all depend on the microorganisms that lives inside, and on us for good health. There is no such thing as an independent organism - all species need other species in order to survive.

The reason why this information is important, is because the lack of diverse-species microbes in the human gut are implicated in many health issues. The American Gut Project shows that people who consume at least 30 different kinds of plant foods per week, have healthier and more diverse gut microbiomes and fewer health issues, than those containing 10 or less different plant foods per week.

Research from Fred Provenza, also shows that livestock diets rich in secondary plant compounds:

  • increase microbial diversity in the gut

  • increase ability to digest a wide variety of feeds

  • improve feed conversion efficiency

  • improve immune function.

The ‘diversity principle’ applies to soils as well…

Video: Dr. Christine Jones presenting her work on community tipping points in soil microbial communities. Video by No-Till on the Plains.

At the 9:00 minute time marker, Christine explores how the diversity principle applies to soils.

Research has already found that the susceptibility to pests and disease, low nutrient status and poor plant productivity, are linked to low diversity in the soil microbiome.

It doesn’t matter if it’s a plant-, an animal- or a human system, if microbes are reduced in the

system, it has become a simplified, and a degraded system. These sentient beings cannot function at optimal capacity without the right set of microbes in them, and around them.

“The increasing temperature, the increasing aridity, has come about through inappropriate land management.” “We have made huge changes to the landscape by simplifying it, by removing trees and plants, and by moving from diverse plantings to fields that now grow only one thing.”

Trials and experiments on plant diversity, its abundant biomass and resilience:

At 12:00 time marker of the video, Christine explores why a diverse plant community supports a diverse microbiome. Also how the soil microbiome responds differently once a certain threshold, or tipping point of plant diversity has been achieved. Christine has seen multiple times - all around the world - that a high plant diversity creates a more robust, drought tolerant paddock with lots of green matter. In her presentation she elaborates briefly on five different examples and shows images in the video:

  1. Six species trial in North Dakota

    Burleigh County Soil Conservation District did a research trial in 2006 in North Dakota that showed how a multi-species cocktail mix of 6 different crop species together, grew significantly better than the 8 individual monocultures planted on their own, during a very dry winter season with only an inch of rain between seeding in late May and harvest in late July. The cocktail mix grown together (cowpea, soybean, turnip, oilseed radish, millet and sunflower) was visibly green, lush and productive, but the monocultures all failed. Dr Kris Nichols explained the results to Gabe Brown who wrote about it in his new book: “Not only were the [mycorrhizal] fungi providing for the needs of one plant, but the fungal hyphae pipeline connects to multiple plants, thus supplying both the nutritional and energy needs of both microorganisms and plants.” This synergy is how nature functions. Jay Fuhrer’s experiment proved that monocultures are detrimental to soil health. (For details on this incredible experiment, read Gabe’s new book Dirt to Soil page 33.)

  2. 12 species trial

    The Chinook Applied Research Association in Alberta, Canada, ran a trial in 2015 that showed a significant difference between a triticale monoculture and a 12 multi-species cocktail crop grown together. The mixed field grew to an abundant green matter, and the single species crop did not thrive, not even going through to yield, even though the field had the opportunity.

  3. 27 species trial

    Another example was during an extremely dry year in South Dakota, where cattle farmer Brett Nix planted a 27 species mix quite by accident. He planted a 5 way mix. He also got rid of all the leftover seed in the shed all sown together in another field. The 27 mix thrived with hardly any rain that year. The 5 way mix failed. There is something about a community of diversity plants that grow together, and support each other, that is evidently better than planting single species plants. It goes beyond the simple idea of complementary planting, wherein each plant is filling a different niche. Christine provides evidence in the form of photos.

  4. Biodiversity experiment

    As example number four, Christine talks about the Jena Experiment in Germany, which is a 15 year multi-factor experiment on how high plant diversity produced greater plant yield than high nitrogen fertiliser use. The research shows that having diverse plants growing together boosted biomass production more, than adding 200 pounds of nitrogen per acre to straight monoculture crops. In other experiments, mixed plant cultures were able to thrive on an inch of water, while strips of monocultures showed severe drought stress. There is a lot of information about the Jena experiment and its results on the internet. It is one of the most famous biodiversity experiments ever done. Also see this video: The Jena Experiment - Why do ecosystems need biodiversity.

  5. New Zealand dairy farmer’s experiments

    Lastly at the 20:28 time marker, Christine talks about the many dairy farmers in New Zealand that acted on her advice to get off high rates of nitrogen fertiliser use, with the use of a bio-stimulant when she toured New Zealand in 2015. She ran 7 soil health workshops across New Zealand with over 700 Farmers and Advisors in attendance. She advised that this practice was detrimental to their soils, plants, animals and waterways. Even the New Zealand government has now put measures in place to curb these detrimental practices, after a huge public outcry due to environmental destruction. Farmers reported back to Christine at her May 2018 revisit, on the difference the weaning off of fertilisers, and the use of a bio-stimulant, had made.

    After listening to Christine many years ago, dairy farmers Jenny and Miah Smith from Wilith Farm, Atiamuri, New Zealand started using a microbial biostimulant on a small area and found that the milk production, animal health and top soil visibly increased. Upon seeing her during her 2018 visit, they enthusiastically shared the photo results showing about 5 - 6 inches of topsoil they had achieved, and with the fact that they had been able to completely eliminate the nitrogen fertiliser use for three years. They were very surprised when Christine recommended that they take it even further, and sow a multi-species forage on top of it. Jenny and Miah put in 5 acres of 12 different perennial plants in one paddock, and the black topsoil results 5 months after were mind blowing. See the photos in the video and compare the white pumice soil grown with ryegrass and clover before, to the black topsoil with the multi-species cover crop afterwards. It’s miraculous!

    Both the microbial and plant diversity rapidly built the topsoil.

    All of the paddocks on the farm have now been converted to multi-species forage with a now large biomass. In addition, they changed the animal rotation from 29 days to 45 days, and milk production went up due to the longer grasses. Christine says that the farmers recently reported that they sometimes extend the rotation to 50 days. Every time they extended it, the milk production increased. The paddocks can also now carry twice as many cows as before, and they leave a 50% residual. According to the slide at 28:18 the beneficial outcomes include:

    1. a CEC increase of 50%

    2. all nutrients (including nitrogen and phosphorus have increased, although none was artificially added)

    3. TOC (Total Organic Carbon) level tripled in top 8 inches (now a metre)

    4. Brix levels tripled

    5. milk production increased by 300 litres when cows cow into that ‘salad’ paddock

    6. Somatic Cell Count halved, cow fertility increase 80%.

    7. it’s costing the farmers less to put in the 12 multi-species forage, than fertiliser use and the animals are healthier and producing more milk.

Please note that these radical changes are happening in places with different climates like Australia and in the USA as well. Farmers all over the world, who have been doing this for some time see remarkable, visible changes. Some of them, like North Dakota regenerative rancher Gabe Brown, have had multiple scientific teams on the farm who capture the data, and who have seen significant improvements year after year.

Christine is going back to New Zealand this year for 5 workshops starting 27 March to 8 April 2019.

Why would farmers not want to do this?

At the 29:00 time marker, Christine explains that she feels that a 12 way plant species should be the minimum kind of diversity needed in a paddock. She says that experience with multiple farmers in New Zealand across the board shows that plant diversity leads to:

  • improved animal nutrition

  • improved growth rates

  • improved milk production

  • improved conception rates

  • reduced dependence on vets

  • and building soils up.

Enhancing plant nutrition, yield and resilience through quorum sensing

At the 30:00 minute time marker, Christine switches the focus of her presentation, and talks about how microbes need to reach a certain critical density before they will initiate any kind of action. In other words, there has to be a certain number of microbes as the tipping point, before they all work together. They regulate gene expression in the microbial population and/or in the host plant or animal. It’s a super-organism of co-ordinated behaviour. Microbes in the human gut (and in the animal’s) can switch genes on and off, depending how many there are, and what kind they are. Likewise, bacteria in the soil around a plants roots can switch those genes on and off. Unfortunately, there are often not enough of the right kind of bacteria in our guts, in the soil and around the plant roots to function. (Think about the use of agrochemicals, like herbicides, with antimicrobial properties, and what antibiotics do in the human gut. They decrease the diversity of the good bugs, and the good bugs themselves, and enable to bad to proliferate.)

At the 32:52 time marker, Christine explains that there are certain genes that a plant needs for drought tolerance, frost, pests, disease and for growth. When there is not enough microbes, important genes remain switched off and de-activated.

Christine says that the same scenario is happening to humans, with the widespread occurrence of auto-immune diseases. At 33:55 Christine describes the anatomy of quorum sensing, and shows how microbes become organised. When there is a lot of plant diversity, there is also a large diversity of their associate microbes. Through chemical-signals, microbes not only know how many same-species microbes are present, but also how many other species there are. Microbes are multilingual and talk to their own kind, and also other kinds. Microbes use this information to decide how they are going to act. They want to determine who is in the minority, and who is the majority in the population. This is why a dominant amount and diversity of good bugs in a terrain are essential. In the human body, things don’t work properly, or communicate properly when those chemical signals are interrupted. This gene switching is very important. Microbes send these signals that switch genes on and off, that can either make a plant, for example, more or less productive. Both a plant and animal genome consist of a complete microbial set. At 41:00 Christine shows an image of how quickly a seed that was dipped in a microbial inoculant liquid before planting, can produce a huge colony of beneficial microbes around the roots after it has just germinated.

“Our soils today are not deficient in minerals, they are deficient in microbes.”
“A quorum in an organisation is that threshold that needs to be present in order to make decisions and conduct business. What we now know about microbial populations is that they also have to meet a threshold in order to achieve “density dependent coordinated behavior.” When that happens, they are working together as a super-organism, capable of tolerating drought, or low nutrient soils, or any of those sorts of things.”

David Montgomery and Anne Bikle:

The Hidden Half of Nature, Exploring the Root-Gut Connection

This presentation was the opening session of the 2019 Winter Conference. University professor and geologist David, and biologist and environmental planner Anne, discussed the connections between soil health and human health from the kind of broad scales that influence civilisations, and also down to the scale of what is currently happening in the human gut. This highly educated pair are not farmers, but they have become interested on how microbial life influences crops and people on the individual- and large scale. The entire 2 hour presentation centres around these three books:

This book looks at the problem of soil erosion and how it has affected societies.

It looks at the state of the land for the last few hundred years, and how the problem of the plow, played out over centuries, can quite literally strip the topsoil off the landscape to the degree that it really affects our ability to support ourselves off agricultural land.

At the 20 minute time marker of his presentation, David notes that even Greek philosopher Plato 427-347 B.C had figured out the connection between soil degradation and the longevity of societies, and well as people’s inability to live off degraded land.

At the 30 minute time marker, he shows how soil can quickly deteriorate due to erosion in tilled fields, and also how the rate at which nature regenerates topsoil is quite slow, and therein lies the problem. He gives readers and watchers all the data they need to calculate how long an agricultural civilisation can last.

This book guides the readers through David and Anne’s personal exploration around how the role microbial life plays a part in the health of plants, animals and the health of people.

It describes their personal journey into why the hidden half of nature is so important, and has been overlooked both in agriculture and medicine.

At the 9:30 time marker of her presentation, Anne explains why she is such a huge fan of growing compost tea as a microbial inoculant to create the black fertile topsoil that cycles nutrients in the soil food web. From the 18:55 time marker, she talks about the elements the plants need and why the rhizosphere (the area around the plant roots) is a biological bazaar where exudates (food exuded from plant roots to encourage microbes to settle) feed microbes. The microbes that grow in the rhizosphere are hugely important to a plant’s wellbeing, because the microbes make minerals available to the plants. They dissolve these essential minerals from the rocks and in a symbiotic relationship, the plants can now take them up via the root structure. The microbes also help to protect the plant by releasing metabolites that stimulate the plant’s immune system, to produce defensive compounds, to get rid of pests. The rhizosphere is a place of incredible plant intelligence thanks to the soil microbes and the two way symbiotic relationship. Anne compares the root system of a plant to the a gut and a brain; a place where many activities are initiated and ‘rationalised’. This root system creates a ‘smarter plant’ can deal with all the challenges mother nature can throw at the botanical world: weather conditions, pathogens etc.

Image: a snapshot from Anne’s presentation. Click to enlarge.

Anne also draws attention to the fact that the diet of the plant is very important. At the 25 minute time marker, she shows a slide about why a plant on a fertiliser diet doesn’t have a good root structure. It has gotten lazy because it has plenty of fertiliser as food. The roots do not attract a lot of microbes and miss out. The plant on the soil health diet enjoys interaction with microbes, enjoys benefits like microbial metabolites, and other micronutrients that are very important in farming when producing food for animals and humans, and for farmers depending on an income from that system. She also briefly discusses why inoculation of beneficial microbes on seed can make a big difference. It allows mycelial networks to grow, connect and support the 'super-organism' under the soil faster. It is also important to realise that there is going to be a difference in performance, between a seed that has been coated in fungicide, and one that has not been exposed to chemicals.

At the 28:26 time marker, she discusses why humans require a microbiome, just like soil. She says that each person received 23,000 genes from our parents, but when you add the genes of our microbial inhabitants, that adds about 2 million genes. These are not only bacteria. They include viruses, fungi etc. All the animals on the farm has this microbiome as well. Anne elaborates on why restoration of both the plant microbiome and the human microbiome are crucial for health. The microbial world is ecological. It is in relation to the host organism and in relationship with other microbes in communities. The plant’s root system and the animal- and human gut are places where careful cultivation should take place. The benefits include immunity and defence… and ultimately health and wellbeing.

This book is a tribute to the farmers and people who taught David the geologist the finer arts of regenerative agriculture, and the way agriculture needs to be done in the future.

At the 22:30 time marker, David talks about taking time off work in 2015 and visiting farmers who were farming differently and regenerating the land quickly. The farmers he spoke to started him on the road to optimism on how the world’s farmland fertility can be restored rapidly, and how farmers can do it very profitably. David and Anne came up with a simple description:

Ditch the Plow, Cover Up, Grow Diversity… and Accelerate it with Livestock.

They found that the benefits of healthy soil were:

  • higher farmer profits

  • comparable yields

  • less fossil fuel, fertiliser and pesticide use

  • increased soil carbon and water retention, less pollution.

David and Anne are now busy collecting scientific information for a fourth book on how regenerative farming is increasing the health of the plants, and therefore the health of animals and humans.

Earth is habitable because it has soil with microbes in it. Change the biology and plant diversity radically, and remove some modern inputs and farmers can regenerate quickly.

Australia’s new $5 billion Future Drought Fund?

Prime Minister Scott Morrison has announced the creation of a $5 billion Future Drought Fund, initially beginning with a $3.9 billion injection in 2019. The money will supposedly be spent on drought projects, long term research and making farmers less susceptible to the dry. Many doubt its value, and with good reasons. We already have the knowledge and science to make significant changes, but there seems to be no political will for promoting regenerative farming practices.

There seems to be a deep political conflict between supporting the status quo and helping farmers in a way that will make a worthy difference. Instead, $31 million for an irrigation project in Gippsland, Victoria is supposed to be one source of drought relief for farmers here, but it is also inevitably a show of support for the continuation of the same old, same old…

A few years ago a book was published titled Climate Change, Capitalism and Corporations arguing that businesses are locked in a cycle of exploiting the world's resources in ever more creative ways, promoting business as usual. The two Australian Professors wrote: "Our book shows how large corporations are able to continue engaging in increasingly environmentally exploitative behaviour by obscuring the link between endless economic growth and worsening environmental destruction." Corporate capitalism is committed to the relentless pursuit of growth and wealth for some, even if it ravages the planet and threatens human health. We need to build a new system: one that can balance economic growth with sustainability and well-being for all, but with politicians who seem resistant to change, and may be influenced by conflicting views on climate change or misinformation, real change will have to start at ground level… without the financial support of taxpayer funds.

The death of an old way of thinking and a re-evaluation of current systems are required. Every human error helps build knowledge and understanding of the world around us. This is an opportunity to ask yourself: What can I learn here, and how can I make the situation better? Mistakes can be huge wake-up calls and realising them sooner, rather than later, can be a blessing in disguise.

It’s a matter of everyone making an effort to set things right.


Please note that much of the evidence to support the statements made in this article can be found in previous articles. See the other articles listed below and also the information in the 11 categories of the Risk Identification and Risk Reduction Program: