What is happening to the agricultural topsoil across the world


Erosion, compaction, nutrient imbalance, pollution, acidification, water logging, loss of soil biodiversity and increasing salinity have been affecting soil across the globe, reducing its ability to support plant life and so grow crops.

Erosion, compaction, nutrient imbalance, pollution, acidification, water logging, loss of soil biodiversity and increasing salinity have been affecting soil across the globe, reducing its ability to support plant life and so grow crops.


How much of the world’s topsoil is degraded?

According to the United Nations’ Food and Agricultural Organization (FAO), a third of the world’s soil is now moderately to highly degraded. The processes that generate high-quality, fertile topsoil can take centuries. But the world is ploughing through that resource at an alarming rate.

Is topsoil the answer to feed the world’s growing population?

The sense of urgency over topsoil is growing as the planet is projected to reach 9 billion people by 2050. Without a healthy farm system, farmers won’t be able to feed the world’s growing population, says Dave Montgomery, a geologist at the University of Washington and author of the book Growing a Revolution: Bringing Our Soil Back to Life.

What are the factors that affect topsoil?

But, there’s various factors that can impact topsoil levels, and the pressure put on topsoil resource (such as food demand, intensity of farming, level of effort put into maintaining soil health, topsoil degradation in different parts of the world, and more)

What is happening to Panama’s topsoil?

The Sarigua desert, west of Panama City, Panama, seen after overgrazing by livestock and the loss of topsoil through erosion. Photograph: Tomas Munita/AP The world grows 95% of its food in the uppermost layer of soil, making topsoil one of the most important components of our food system.


What is happening to topsoil?

Topsoil can erode due to strong winds, hard rains and flowing water. Farming practices like tilling, the process farmers use to overturn the ground to prepare it for crops, leave the soil vulnerable to surface runoff. One way to help mitigate the loss of topsoil is to have farmers use no-till practices to grow crops.

Why are we losing topsoil all around the world?

But thanks to conventional farming practices, nearly half of the most productive soil has disappeared in the world in the last 150 years, threatening crop yields and contributing to nutrient pollution, dead zones and erosion. In the US alone, soil on cropland is eroding 10 times faster than it can be replenished.

What is happening to the worlds soil?

The world’s soils are also being damaged by other factors including erosion, acidification, salt contamination and compaction. A 2017 report found that a third of the planet’s land is severely degraded and that fertile soil was being lost at the rate of 24bn tonnes a year.

How does agriculture affect topsoil?

When agriculture fields replace natural vegetation, topsoil is exposed and can dry out. The diversity and quantity of microorganisms that help to keep the soil fertile can decrease, and nutrients may wash out. Soil can be blown away by the winds or washed away by rains.

How much of topsoil is gone?

The study estimated that about 35 percent of the region has lost its topsoil completely, leaving carbon-poor lower soil layers to do the work of supporting crops. Having thick, healthy topsoil means plants can grow faster and healthier, increasing crop yields and keeping the field’s ecosystem running smoothly.

What are some of the causes of our soil crisis?

In the last few decades, soil degradation has been sped up by intensive farming practices like deforestation, overgrazing, intensive cultivation, forest fires and construction work. These actions disturb soil and leave it vulnerable to wind and water erosion, which damages the complex systems underneath.

Is soil going extinct?

In the US alone, more than 20,000 soils have been catalogued. Many are facing extinction. It may seem like madness to speak of soils going extinct, but more than a third of the world’s top layer is endangered, according to the UN, which declared 2015 the International Year of Soils.

How farming destroy the quantity of soil?

Firstly, erosion reduces the capacity of the soil to hold water and make that water available to plants. This subjects crops to more frequent and severe water stress. Secondly, erosion contributes to losses of plant nutrients, which wash away with the soil particles.

How does agriculture cause soil pollution?

Agriculture and livestock activities pollute soil through excessive application of pesticides and fertilizers, the use of untreated wastewater for irrigation, and the use of manure and sewage sludge with high antibiotic, antimicrobial-resistant bacteria and heavy metal content.

How agriculture contributes to soil erosion?

Vegetation cover The loss of protective vegetation through overgrazing, ploughing and fire makes soil vulnerable to being swept away by wind and water.

How much of the world’s soil is degraded?

According to the United Nations’ Food and Agricultural Organization (FAO), a third of the world’s soil is now moderately to highly degraded. The processes that generate high-quality, fertile topsoil can take centuries. But the world is ploughing through that resource at an alarming rate.

How much soil did Iowa lose in 2014?

In just one spring in 2014, Iowa lost nearly 14 million tonnes of soil from its cropland in a series of storms, according to environmental groups. A study of 82 sites in 21 counties by Iowa State University showed that in the 50 years from 1959, soil structure and levels of organic matter had degraded while acidity had increased.

Why is soil degraded?

Soils are becoming severely degraded due to a combination of intensive farming practices and natural processes. As the layer of fertile topsoil thins, it gets increasingly difficult to grow crops for food.

How do prairie strips help soil?

Research has shown that the prairie strips can generate a 20-fold reduction in the amount of sediment being washed off fields. They also retain more nitrogen and phosphorous by helping to reduce the amount of water from running off the surface.

How much land is degraded?

According to some estimates, between one billion and six billion hectares of land are now considered to be degraded. But the problems vary greatly from region to region. In a handful of places, this degradation has happened naturally, says Vargas.

Is there a shortage of mud and dirt?

At first glance, it might seem that there is no shortage of mud and dirt around the world. But it’s the quality that really counts. “Many types of soil degradation are invisible,” says Ronald Vargas, secretary of the global soil partnership at the FAO in Rome.

Is soil a living thing?

Living systems. Soil is largely made up of grains of weathered rock and the remains of dead, decayed plants. But it is far from an inert, lifeless substance. Soil is a living system bursting with microbes, fungi, insects, worms and other invertebrates. These all play important roles in breaking down material, delivering nutrients to plants …

How much topsoil has been lost in the last 150 years?

When looking purely at topsoil loss, one estimate says half the world’s topsoil has been lost in the last 150 years. When looking at the amount of cropland abandoned because of soil erosion/degradation, about a third of cropland might have been abandoned over the last 40 years.

How much topsoil is left?

Some estimates say that the world has about 60 years of topsoil left. In the United States, about a third of topsoil is forecast to be lost over the next 12 years, but the population size is forecast to increase as well.

How much soil has been lost since the colonial days?

Some of the estimates for the United States’ soil loss are: – Half the soil has been lost since colonial days. – Average topsoil depth across America might have decreased from 18 inches to 8 inches today. – Specific States have their own average topsoil loss amounts.

Why is the world’s cropland abandoned?

During the past 40 years nearly one-third of the world’s cropland (1.5 billion hectares) has been abandoned because of soil erosion and degradation. As a result of erosion over the past 40 years, 30 percent of the world’s arable land has become unproductive. – fewresources.org.

What are the variables that affect topsoil loss?

Other variables to future topsoil loss might include future breakthroughs in soil technology and practices, how effective soil amendments and organic matter can be in increasing soil health, how effective importing soil can be, and so on.

How deep is topsoil in Canada?

In Canada, average topsoil depth varies anywhere between 10 to 25 cms depending on the area.

How long does it take for topsoil to renew?

The current high erosion rates throughout the world are of great concern because of the slow rate of topsoil renewal; … it takes approximately 500 years for 2.5 cm layer of fertile topsoil to form under agricultural conditions. – globalagriculture.org.

Why is the third of the Earth’s soil degraded?

Third of Earth’s soil is acutely degraded due to agriculture. This article is more than 3 years old. Fertile soil is being lost at rate of 24bn tonnes a year through intensive farming as demand for food increases, says UN-backed study. Soil erosion in Maasai heartlands, Tanzania, is due to climate change and land management decisions.

How much of the world’s cropland is decreasing productivity?

The JRC noted that decreasing productivity can be observed on 20% of the world’s cropland, 16% of forest land, 19% of grassland, and 27% of rangeland. “Industrial agriculture is good at feeding populations but it is not sustainable.

What are the impacts of poor land management?

Worst affected is sub-Saharan Africa, but poor land management in Europe also accounts for an estimated 970m tonnes of soil loss from erosion each year with impacts not just on food production but biodiversity, carbon loss and disaster resilience. High levels of food consumption in wealthy …

What is the global land outlook?

The Global Land Outlook is billed as the most comprehensive study of its type, mapping the interlinked impacts of urbanisation, climate change, erosion and forest loss. But the biggest factor is the expansion of industrial farming.

What will be the biggest challenges in 2050?

In a series of forecasts on land use for 2050, the authors note that sub-Saharan Africa, south Asia, the Middle East and north Africa will face the greatest challenges unless the world sees lower levels of meat consumption, better land regulation and improved farming efficiency. Topics. Soil. Agriculture. Farming.

How much of Europe’s soil is degraded by humans?

We can consider that agriculture is responsible for 80% of the soil degradation in Europe and scientists estimate that 40% of lands in Europe are already degraded because of human actions. If playback doesn’t begin shortly, try restarting your device.

How does machinery affect soil?

Soil compaction. Induced by machinery use leads to a reduction in biological activity, porosity and permeability. It reduces water storage and conduct and make soil less permeable to plant roots, can affect water infiltration capacity and increase erosion risk by accelerating run‐off. Livestock.

What causes soil biodiversity decline?

Biodiversity decline. Induced by soil contamination, erosion, salinisation and sealing; Soil biodiversity reflects the mix of living organisms in the soil. These organisms interact with one another and with plants and small animals forming a web of biological activity. Soil compaction.

How many ha of soil are affected by human induced soil degradation?

Globally, human-induced soil degradation has affected 1965 million ha. In the case of the World’s drylands, estimates by Dregne and Chou (1992) indicated that the continents of Africa and Asia are particularly affected by land degradation.

What is soil degradation?

Soil degradation is a process in which the value of the land and its biophysical environment is affected by a combination of human actions and non-natural phenomenons. The degradation comes from several sources but it is mainly from extensive agriculture.

How does land degradation affect the world?

Land degradation is happening at an alarming pace and is affecting regions inhabited by over one-third of the global population. This phenomenon contributes to a dramatic decline in the productivity of croplands and rangelands worldwide, thereby, threatening food security and environmental quality.

How much of the world’s land is degraded?

The areal extent of global degraded areas varies depending on the definitions. Globally, about 24% of the global land area has been affected by degradation and over 1.5 billion people live on degraded lands. Globally, human-induced soil degradation has affected 1965 million ha.

Buy The Book

Some of the worst erosion in the United States is in the Midwest, where our valuable Mollisols are concentrated. It was during a phone call from the White House about water erosion in Iowa with soil scientist Rick Cruse that I began to realize that soil erosion is in fact a slow-burning national crisis for the United States.

What Will We Reap Without Topsoil?

Despite Iowa’s relatively gentle slopes, the state has lost enough soil to see disturbing yield reductions, and the projections for the future are bleak. In 2007, Iowa reported that 4 million hectares had each lost 11 tonnes of topsoil and an additional 2.4 million hectares had eroded at twice that rate.

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Meet the Writer

Jo Handelsman is a soil scientist, director of the Wisconsin Institute for Discovery, and author of A World Without Soil: The Past, Present and Precarious Future of the Earth Beneath Our Feet. She’s based in Madison, Wisconsin.

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Soil erosion continues at record pace around the world. Soil scientist Jo Handelman explains the good news: The solutions are simple and well-understood.

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Why is soil loss so bad?

There is much debate about the precise rates of soil loss, but little debate that it is a problem and growing worse in many parts of the world, either due to the nature of the industrial farming techniques that place unbearable stresses on the land or due to the sheer quantity of land being converted to agricultural or animal grazing purposes. A report by the Environmental Working Group on what’s happening in the heart of America’s cornbelt illustrates what is at stake and the extent to which a business-as-usual attitude conceals one of the most important economic and environmental trends of the modern era.

What happens when weather patterns disrupt the soil?

Weather pattern disruption can lead to excessive runoff that leaves behind large gullies and in the process removes vital nutrients from the remaining topsoil. The same consequences can arise from overuse of nitrogen-intensive fertilizers that require large quantities of water.

What are the causes of soil degradation?

There are differences in the types and causes of soil degradation around the world. In some regions, overgrazing is a major cause, while in others the primary cause lies with other types of agriculture . One of the major causes shown on the accompanying charts from UNEP/FAO is deforestation, but in increasing numbers of instances, deforestation itself is caused by efforts to make more land usable for either grazing by animals or the planting of crops – which increasingly is destined for livestock feeding. See, for example, Livestock’s Long Shadow.#N#Soil degradation also varies by type. Water erosion, for example, can be a consequence of many causal vectors. Weather pattern disruption can lead to excessive runoff that leaves behind large gullies and in the process removes vital nutrients from the remaining topsoil. The same consequences can arise from overuse of nitrogen-intensive fertilizers that require large quantities of water.#N#The primary causes and types of soil degradation thus differ around the world.

How does intensification affect soil?

Intensification has led to massive soil depletion, but devoting even more land to similar intensive agricultural uses simply speeds up the aggregate loss of fertile soil available to feed a growing planet with a growing appetite for food production that makes large demands on soil resources.

How fast is soil erosion?

Here are some of the key findings: The United States is losing soil 10 times faster — and China and India are losing soil 30 to 40 times faster — than the natural replenishment rate.

How long does it take to replace 25 millimeters of topsoil?

has somehow changed “It takes approximately 500 years to replace 25 millimeters (1 inch) of topsoil lost to erosion.

What has changed over the last 10 years?

The numbers are telling, and they carry us only through 2002. Things have changed over the last 10 years, in particular, the trend toward greater meat consumption. That means, among other things, that more land per person may be required to support a very much altered diet than the world as a whole enjoyed in 1960.


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