Agriculture & Soil Degradation

Our soils support 95 percent of all food production, and by 2060, our soils will be asked to give us as much food as we have consumed in the last 500 years. They filter our water. They are one of our most cost-effective reservoirs for sequestering carbon. They are our foundation for biodiversity. And they are vibrantly alive, teeming with 4500 kilo’s of biological life in every acre. Yet in the last 150 years, we’ve lost half of the basic building block that makes soil productive. The societal and environmental costs of soil loss and degradation in the United States alone are now estimated to be as high as $85 billion every single year. Like any relationship, our living soil needs our tenderness. It’s time we changed everything we thought we knew about soil. Let’s make this the century of living soil.

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. Land degradation is, therefore, considered as a major global environmental issue of this century.

The degradation of our soils, due to human activities, today, can harm our well-being. It causes the extinction of species and accentuates climate change. It also contributes to the displacement of populations and the multiplication of conflicts.

A major part of soil depletion is due to the lands over-use and the products that we pour on it. 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.

A brief climate change video essay that looks at why the issue of soil degradation matters. Specifically, I look at how we've arrived at such poor soil conditions as a result of modern industrial agricultural practices and why this issue is important when facing climate change.

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. 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.

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. This results is depletion, erosion, modification or disturbance of the soil that is considered harmful or undesirable. This degradation leads to a phenomenon which is the disappearance of nutrients and minerals needed for plant growth.

This phenomenon has a lot of negative effects on the planet and can become one of the main problem for fighting against the lack of food.

Soil
Soil is the earth’s fragile skin that anchors all life on Earth. It is comprised of countless species that create a dynamic and complex ecosystem and is among the most precious resources to humans. Increased demand for agriculture commodities generates incentives to convert forests and grasslands to farm fields and pastures. The transition to agriculture from natural vegetation often cannot hold onto the soil and many of these plants, such as coffee, cotton, palm oil, soybean and wheat, can actually increase soil erosion beyond the soil’s ability to maintain itself.

In this video Paul Andersen explains how soils are formed and classified. Weathering of rock creates particles which are mixed with water, air, and organic material. Soils are classified according to particle size, chemical makeup, and horizon distribution. A brief discussion of soil loss through erosion, compaction, and salinization is included.

Eight major aspects of soil degradation in Europe have been identified including biodiversity decline, contamination, erosion and organic matter decline.

All these problems have considerable economic and environmental consequences and could eventually compromise food production.

This animated film tells the reality of soil resources around the world, covering the issues of degradation, urbanization, land grabbing and overexploitation; the film offers options to make the way we manage our soils more sustainable.

Some major aspects identified as drivers of soil degradation are:

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
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
In this desertification of our soils we can target livestock and animal exploitation as the biggest actor in the changes that we know.

Livestock are also responsible because of their excrement, which are highly toxic for the atmosphere. When too many animals are concentrated in a small area, the amount of excrement, in the long term, can degrade the soil and create erosion, in addition to the greenhouse emissions.

But even if animals are spread over a big territory, the soil can suffer from degradation. A cow for example, can eat between 40 and 75 kg of food per day. So, if we consider that they are on the same land all year long, they will eat all the resources without the possibility of regeneration for the soil.

Livestock are also responsible indirectly with the land needed, to grow their foods. Because it is not directly for human consumption, people use to give to animals second-class agricole products, like GM(genetically modified)  soja, GM corn or even animal origin flour.

These exploitations are massively polluting and source of soil erosion. For example, in South America, we consider that 60% of the soil is degraded and 70% of this degradation comes from the land used to grow food for animals.

Cultural inappropriate practices
Practices in the agricultural world are one of the biggest threat for the soil. Farmers in the previous 50 years did not pay attention to the soil, animals or even people who used pesticides and fertilizers in big quantities. Now the biggest threat is GMOs but all the products used in the past, are still used which make the agricultural world even worse.

Soil salinization (irrigation)
Soil salinisation is, in some regions, is a huge problem for the agricultural world. It can lead to the reduction of soil productivity or even the impossibility to grow plants.

As rocks and soil are eroded by water, small amounts of the mineral salts they contain are carried to rivers and lakes.

Thus, the latter seep into the irrigation water. If an insufficient amount of water is used in a field, the salts become encrusted in the soil. But the most serious danger for the soil is too much water.

In fact, in these conditions, the soil is engorged and raises the level of the water under the first layer of soil. The soil then functions as a sponge and absorb water into the rhizosphere by capillarity.

This effect can attract water to the surface for about 1.5 m, depending on soil types. Water evaporates and salt stays around the roots, impeding their ability to absorb water. A process encountered particularly in arid regions.

Currently, only 17% of all agricultural land is irrigated. But they account for 40% of worldwide food production. This is why we should start thinking about soil salinization.

Dirt, soil, call it what you want—it's everywhere we go. It is the root of our existence, supporting our feet, our farms, our cities. David R. Montgomery finds, however, that we are running out of dirt, and it's no laughing matter.

Use of pesticides
Pesticides have several impacts on the environment. In terms of soil and soil degradation, they are responsible for the phenomenon of erosion, which is the loss of the first soil layer. This is due to the lack of plants and trees that can keep the soil strong, but also the lack of insects which are killed by pesticides.

Erosion causes a deficiency in basic nutrients (nitrogen, phosphorus, potassium, calcium), essential for agricultural production. More present on the surface, they leave with the runoff. It is in Asia, Africa and South America that the erosion hits the highest: a loss of 30 to 40 tons of soil per hectare per year. About 17 tonnes per year in Europe and the United States. On every continent, this erosion extends well beyond the capacity of soil renewal: about one ton of land per year per hectare.

Deforestation and Monoculture
Biodiversity is a complex process that permits evolution, thanks to the diversity of all its composants. The differences between species, allows them to need each other, for relations of predation, mutualism or even for reproduction. If we have only one species of trees, for example, in a forest, these trees will die because they need other plants and animals for food, protection, pollination…

The problem of monoculture is linked to deforestation because when people cut an entire forest, most of the time, in order to plant one type of soja, one type of palm tree or one type of wheat. This leads to an overconsumption of minerals by this type of plant, a lack of food for worms, insectes and every living being which implies a degradation of the soil.

All these agricultural changes will have seere effects on our environment and will lead to an agricultural crisis and food crisis. Effects of agriculture are direct and affect more and more people. We must know that humans are part of the ecosystem, we can destroy it without being affected by the changes.

What is soil and soil degradation? Soil explained and soil erosion explanation. Soil is the foundation of life. It is a medium for trees and plant growth and a habitat for many insects and other organisms. Agroforestry and permaculture soil intro. As much as 95 percent of all our food comes from soil. Soil also plays a key role in filtering water and absorbing carbon. Yet, what is the current state of the world soil resources?

Greenhouse emissions
Climate change also may worsen soil degradation, underlines the report, related to more frequent and more severe droughts. Other than in tropical ecosystems, soil contains about twice as much organic carbon as above‐ground vegetation. There is growing realisation of the role of soil, in particular peat, as a store of carbon and its role in managing terrestrial fluxes of atmospheric carbon dioxide (CO2).

While climate is a key soil forming factor and governs a large number of pedogenic processes, soil can also influence global climate. Soils in the northern latitudes store huge amounts of organic carbon, much of which is affected by permafrost and permanently or seasonally frozen. Currently, around 500 Gt of carbon is stored in permafrost‐affected soil in the northern circumpolar region. Large releases of greenhouse gases from these could have a dramatic effect on global climate, although the exact relation is complex and requires additional research.

Unless suitable land management procedures are implemented, increased and more severe droughts will cause soil water retention mechanisms to collapse, leading to the onset of erosion, desertification and increased risk of flooding.

This 60-minute documentary features innovative farmers and soil health experts from throughout the U.S.

Flooding
Land is commonly altered from its natural landscape when it rids its physical composition from soil degradation.  For this reason, the transformed land is unable to soak up water, making flooding more frequent. In other words, soil degradation takes away the soil’s natural capability of holding water thus contributing to more and more cases of flooding.

Jared explains why erosion occurs more slowly when soil is paired with leaf debris or plants, in this simple demonstration you can try at home

Extinction of species
Even if extinction of species is not the first thing we think about when we speak about soil erosion, it is one of its effects. In fact it is one the biggest source of animals disappearance. 40% of the worm population has disappear since 1950. The most obvious cause is certainly pesticides that are very harmful for them. But salinisation represent a big source of death due to the sensitiveness of worms to salt.

We can consider as a consequence of the loss of million worms, the disappearance of numerous species of birds that fed on worms. These effects can be felt by humans as well, later because we are at the top of the food chain, but we will feel it one day.

Solutions

Several solutions already exist. We initially can take a look at how our ancestors. These solutions, implies a small time travel in the past, and at the use of ancestral techniques that prevented food crisis hundreds of years ago.

For example, proper drainage was used by the Greeks two thousand years ago. Using diversity to help the plant growth was also an ancestral technique that Egyptians used in their fields. The agricultural world of this time was a factor of diversity creation by exchanging varieties of fruits and vegetables, by testing new varieties next to old ones, evolution was allowed. Nowadays the visions that we have is reductionist and is based only on productivity and money. But even if it seems impossible to change, agriculture can be improved in favor of the environment. There are still techniques that can help our soils to recover to their former condition.

Simple steps and innovative thinking will help improve the quality of soil in the country

Leaching
By giving crops a little more water than necessary (but without exaggerating), salinity is reduced in the root zone. The salts are transported in the aquifer which disperses them, provided that the natural drainage is sufficient.

Drainage
Ditches or underground pipes can carry salt water. 1/3 of the saline soils, could be improved thanks to a better drainage and a series of techniques adapted to the local situation. Example: Over the past 30 years, the Egyptian National Drainage Program has been addressing water saturation and soil salinity using different types of drainage and pumping stations. This facilitated the flow and reuse of drainage water.

Benefits of diverse plantation
Diversity of plants and animals is certainly the main point if we want a healthy soil. The exchanges of nutrients, minerals and the activity of worms are the most effective solution, but it implies to avoid the use of pesticides and all chemical products that can harm or kill them.

Stop using GMOs
When people modify an organism, the goal is to change this organism to a pesticide resistant one. It implies that to grow this type of plant we need pesticides. But the real problem is that pesticides can kill every other organism in contact with this product. If monoculture happens in addition to the use of pesticides, you can kill a soil in less than two years (not enough nutrients for any type of plant).

The Orinoco Basin extends across Veneuela and Colombia. The river's delta is covered with tropical rain forest. For many years now, colossal palm oil plantations have been encroaching on this forest. But the forest floor is relatively poor in nutrients and rich in oxygen, making it unsuitable for monocultures. Planting many diverse crops in the same ground can help balance out soil use.

Use more organic residues
Many producers do not add or just little organic residues to their soils. A study by the Quebec Ministry of Agriculture, carried out from 1990 to 2000, showed that, on average, soils had been depleted by 0.1% per year. But the problem is sometimes much more serious in some places.

How to remedy the situation? We must add manure, natural fertilizer or residual materials. Another option is to leave as much organic matter as possible. For example, when we produce corn, we can cut the corn and let the rest of the plant on the ground. This practice can increase the number of nutrients in the soil and create attractiveness for worms and insects that are sources of nutrients for plants.

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Sources:

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