Global Threats: Soil and Topsoil Erosion and Degradation
By Roberta Attanasio
“Soil anaemia also breeds human anaemia. Micronutrient deficiency in the soil results in micronutrient malnutrition in people, since crops grown on such soils tend to be deficient in the nutrients needed to fight hidden hunger. (…) Managing our soil and water resources in a sustainable and equitable manner needs a new political vision.” M.S. Swaminathan — the “Indian Father of Green Revolution”.
Soil, the earth’s skin, is one of our most valuable resources — it’s a dynamic and complex ecosystem that acts as a growing medium. Plant and animal life depend on the recycling of primary nutrients through soil processes. It plays a major role in determining the composition of the atmosphere by emitting and absorbing carbon dioxide, methane, and water vapor and, due to its water filtering function, is essential for the clean water supply of our planet.
Soil degradation is the decline in soil quality caused by its improper use. Examples of soil degradation are loss of organic matter, decline in soil fertility, decline in structural condition, erosion (soil is naturally removed, for example by the action of water or wind), adverse changes in salinity, acidity or alkalinity, and the effects of toxic chemicals, pesticides, pollutants or excessive flooding.
Back in 1984, a study by the Worldwatch Institute defined the erosion of agricultural topsoil a ”quiet crisis” that could lead to “pockets of famine” around the world. At the time, Lester R. Brown told the New York Times: ”Grave though the loss of topsoil may be, it is a quiet crisis, one that is not widely perceived. Unlike earthquakes, volcanic eruptions and other natural disasters, this disaster of human origin is unfolding gradually.”
Then, in 1992, the World Resources Institute published the results of the first global assessment of land degradation. It reported that, since World War II, about 11 percent of the world’s vegetated surface area had become degraded, mostly due to farming, overgrazing and deforestation. It pointed out that the continuation of activities leading to soil degradation would seriously affect the ability of providing growing populations with food, fuel, and fiber.
Now, more than twenty years later, The Global Soil Partnership — which brings together a broad range of government and non-government stakeholders — recognized that urgent action is required to improve the health of the world’s limited soil resources and stop land degradation, so as to ensure that future generations have enough supplies of food, water, energy and raw materials. Thus, it has endorsed a series of action plans to safeguard soil resources which provide the basis for global agricultural production.
Maria Helena Semedo, Deputy Director-General of the FAO (Food and Agriculture Organization of the United Nations), said: “Soil is the basis for food, feed, fuel and fibre production. Without soils we cannot sustain life on earth and where soil is lost it cannot be renewed on a human timeline. The current escalating rate of soil degradation threatens the capacity of future generations to meet their needs.”
Recommendations include the implementation of strong regulations and corresponding investments by governments for the sustainable management of soils in ways that contribute to the eradication of hunger, food insecurity and poverty.
Soil degradation may also have a significant impact on global warming due to release of carbon in the atmosphere. According to FAO, since the 19th century, an estimated 60 per cent of carbon stored in soils and vegetation has been lost as a result of changes in land use, such as clearing land for agriculture and cities. The first meter (about 3.2 feet) of Low Activity Clay soils (the majority of the upland soils in the humid and sub-humid tropics) contains approximately 185 Gigatons (one Gigaton = one billion metric tons) of organic carbon — an amount which doubles that of organic carbon stored in the Amazonian vegetation. Through unsustainable soil management practices, this carbon could be released to the atmosphere, aggravating global warming linked to the burning of fossil fuels. A release of just 0.1 percent of the carbon now contained in Europe’s soils would be equal to the annual emissions from 100 million cars.
Semedo added: “That’s why the adoption of Global Plans of Action to sustainably use and protect soils is a major achievement. But we cannot stop here. We need commitments from countries and civil society to put the plan into reality. This requires political will and investments to save the precious soil resources our food production systems depend on.”
Below are the five pillars of action established by The Global Soil Partnership:
- Promote sustainable management of soil resources for soil protection, conservation and sustainable productivity
- Encourage investment, technical cooperation, policy, education awareness and extension in soil
- Promote targeted soil research and development focusing on identified gaps and priorities and synergies with related productive, environmental and social development actions
- Enhance the quantity and quality of soil data and information: data collection (generation), analysis, validation, reporting, monitoring and integration with other disciplines
- Harmonization of methods, measurements and indicators for the sustainable management and protection of soil resources
7 Comments
Ray Kinney
In western Oregon salmon habitat forests of the Pacific Northwest, copious leaching rainfall depletes essential micronutrients in forest soils. For many thousands of years we have given thanks that our forest garden has been fertilized with ocean-derived micronutrients in the form of millions of spawning salmon and lamprey. When you don’t fertilize your garden adequately you can not expect the quality of your vegetables and fruits to remain high through the years. Currently, we have a fertilization emergency going on in our salmon streams because our soils no longer benefit from the addition of the prehistoric levels of fish fertilizer that we have always had in the past. Soil fetility has dropped. How can we expect to regain salmon populations and support their healthy development without having more spawners fertilizing our watersheds like they used to? We now require massive more amounts of spawners to support increased numbers of new young salmon before we can expect the young ones to be healthy enough to survive the freshwater phase of their life cycle… we can’t get there from here… it’s a chicken and egg problem. Our land use and extractive natural resource harvests have depleted the systems fertility too much. Our slightly acidic rains now leach what little nutrient remains down to the ocean too fast, and it does not return with salmon numbers as it used to. When we further damage these soils with additional nutrient depleting land use practices,such as herbicide applications, soil compaction, and increased erosion, we are shooting ourselves in the foot. Our soils desperately need those ocean-derived nutrients to once again be brought back up here into the whole watershed like it used to happen. Similar soil fertility depletion scenarios are happening in agricultural soils everywhere as current agricultural production practices continue to allow extractive divestment of micronutrients washing to the ocean deadzones. The essential complexity of micronutrients lost does not get adequately resupplied by current practices and our food quality suffers as a result, therefore, our health outcomes suffer just as the soil fertility suffers as we poison our agricultural crops. Our understanding of biochemical complexity is not good enough yet for us to adequately guide commercial food production for quantity and quality. Instead we take dangerous and damaging shortcuts.
Roberta Attanasio
I agree with what you said, Ray. The relationship between salmon and different biological systems is fascinating, including the positive impact salmon has on wildlife and soils. Salmon give us a major contribution (among others, of course): the flow of nutrients from marine ecosystems to freshwater and forests and more. Healthy and thriving salmon populations are our hope to minimize the ecological damage suffered by the Pacific Northwest. At least this region has the salmon hope. I’m not sure what’s available on the other coast and inland.
Simon Suarez
I agree with the concerns expressed above. There is something more to take into consideration about having more soil and cropland as compared to timberland. Replacing forests with cropland worldwide is at the basis of some cooling effects on global temperatures and, as we know, we do need cooling. Such cooling occurs because the loss of forests reduces global emissions of biogenic volatile organic compounds and these compounds control the atmospheric distribution of pollutants that are involved in climate change (methane is one of them). I hope that we can keep understanding more of the global processes that regulate the health of soils as well as climate and everything affected by it.
Ray Kinney
Simon.
• On the left coast of the US, in Oregon, forestry practices often burn huge quantities of wood debris from logging practices. Carbon is released, deep rich soils are depleted, water retention is decreased, corporate ‘profits’ are maximized. EIA’s are done all the time… not much changes. Corporate profits dictate that all this ‘waste’ be quickly burned, and fears of forest fires agree. Why do EIA’s not point out the need for reuse of all this carbon material and call for sequestration in agricultural soils via biochar production? Well,… that would not ‘maximize’ short term profit by corporations. Short term thinking is killing us. Why do we not change our assessment methodologies quickly to adapt to the need for our survival by developing longer term solutions to such ‘waste management’ problems by seeing how long term gains can be initiated if we just use some logic rather than egocentrically looking to only maximizing ‘profit’. What this really means, is that we are not going to be in time. We are in deep doo doo if EIA’s continue to avoid this short term/long term conceptual error.
Ray Kinney
No comments on this one during all this time… It is disheartening that this subject matter is not considered ‘sexy’ enough to warrant comment.
Here on the left coast of the US, our forests are rapidly being converted into monocrop agricultural ‘forest’ i.e timberland. During this massive process, oldgrowth climax forests lose their soil characteristics in dramatic fashion, greatly reducing ecosystem services of deep water-retentive, water-filtering, air and water cooling ability… which brings many water quality problems to our salmon streams.Duff quality is almost eliminated.
These new ‘forests’ are then sprayed with high concentrations of herbicides to reduce crop-competition from unwanted species resprouting. Water quality sampling and analysis is discouraged by the legislative control of the regulatory agenda, therefore, pointedly investigative environmental assessment goes largely unaccounted for, so funding and project prioritization becomes more irresponsible as a result.
Soil health is vastly understudied and underappreciated. For many years, industrial smokestack waste accumulation was reclassified from ‘toxic waste’ that had a high cost of disposal, to become ‘loopholed’for reclassification as ‘a soil ammendment’. Vast agricultural lands then had toxic chemicals applied as soil amendment… and the companies got paid for doing this. This was a national tragedy that really got very little attention, yet polluted vast stretches of valuable farm land… that we now have contributing contaminants into our food supply. Time after time our soils are abused and our wellbeing becomes more difficult for the long run.
Roberta Attanasio
Thanks, Ray, for bringing up these important points. If it’s true (and I think it is) that seven-tenths of forest lands in the U.S. are timberlands, then what you say is scary – the things you describe may be happening not only on the west coast, but all around….
Ray kinney
Yes, happening all around, we destroy what we don’t understand. We don’t understand soils, what really happens under the ground.We don’t understand roots, and mycelium, and pheromones, and as-yet-unidentified molecules that are crucial for healthy tree communities. Our human-centric bias blinds us to ‘groking’the soil mechanisms of ecology and communication inherent in the beauty of forests left relatively undisturbed. The ecosystem service values to us are huge, yet almost always downplayed during natural resource management and extractive thought.Funding prioritization biases against creative investigatory research to clarify this void of knowledge is crucial opportunity lost. Most industry-funded research is geared far too aggressively toward short term profit at the expense of gaining a deeper understanding of the complexity we disturb. In the long run, deeper understanding is going to be a better basis for our future resiliency for adapting to changes enough to survive rapidly approaching challenges than current profit gain.IMHO