Soil regeneration

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Soil

Soil regeneration, as a particular form of ecological regeneration within the field of restoration ecology, is creating new soil and rejuvenating soil health by: minimizing the loss of topsoil, retaining more carbon than is depleted, boosting biodiversity, and maintaining proper water and nutrient cycling. [1] This has many benefits, such as: soil sequestration of carbon in response to a growing threat of climate change, [2] [3] a reduced risk of soil erosion, [3] and increased overall soil resilience. [1]

Contents

Soil basics

Soil quality

Topsoil organisms bar graph Topsoil organisms bar graph.jpg
Topsoil organisms bar graph

Soil quality means the ability of the soil to "perform its functions." [4] Soil is integral to a variety of ecosystem services. These services include food, animal feed, and fiber production, climate moderation, waste disposal, water filtration, elemental cycling, [1] and much more. Soil is composed of organic matter (decomposing plants, animals, and microbes), biomass (living plants, animals, and microbes), water, air, minerals (sand, silt, and clay), and nutrients (nitrogen, carbon, phosphorus). [4] For optimal plant growth, a proper carbon to nitrogen ratio of 20–30:1 must be maintained. [3] Promoting biodiversity is key to maintaining healthy soil. [5] This can be done by growing a variety of plants, always keeping soil covered, maintaining a living root system, and minimizing soil disturbance. [5] Macro and micro organisms assist with processes such as decomposition, nutrient cycling, disease suppression, and moderating CO2 in the atmosphere. [1] Plants have a particularly symbiotic relationship with microbes in the rhizosphere of the soil. [5] The rhizosphere is an "area of concentrated microbial activity close to the root" and where water and nutrients are readily available. [5] Plants exchange carbohydrates for nutrients excreted by the microbes, different carbohydrates support different microbes. [5] Dead plants and other organic matter also feed the variety of organisms in the soil. [5] Organisms like earthworms and termites are examples of macro organisms in the soil. [1] A good indication that you have quality soil is a lack of pests and diseases. [1] Low biodiversity increases the risk of pests and diseases. [5]

Soil degradation

Soil degradation attributing factors, causes, and effects Soil degradation venn diagram.png
Soil degradation attributing factors, causes, and effects

Having too much or too little of any of the components of soil can cause soil degradation. For example, having a high clay content reduces aeration and water permeability. [3] Another example is that, though phosphorus and nitrogen are essential for plant growth, they are toxic in high amounts. [3] Soil degradation means that soil quality has diminished, which causes ecosystem functions to decline. [1] One third of the globe's land has degraded soil; [1] especially the tropics and subtropics with around 500 million hectares. [1] Soil degradation occurs due to physical, chemical, and biological forces. [5] These forces can be natural and anthropogenic. [5] [1] Tilling is a physical example which causes erosion, compaction, and decreased microbial activity. [5] Erosion is “one of the most serious problems facing urban soil quality", [4] and the problem is exacerbated by uncovered soil. [4] Compaction occurs when soil is pushed together and becomes harder, so the ability to retain air and water is diminished. [4] This increases erosion and flooding, diminishes the ability of plants to grow good root systems, and reduces biological diversity. [4] Overgrazing is another example in which the root system beneath the soil is damaged, reducing water permeability. [5] Acidification, salinization, nutrient leaching, and toxin contamination are a few types of chemical degradation. [1] Toxins can accumulate in the soil from industrial processes like mining and waste management. [3] Some biological examples include biodiversity loss, emitting greenhouse gasses, reduced carbon content, and a reduced capacity to sequester carbon. [1] One of the most predictable ways to determine whether soil degradation has occurred is to measure its organic carbon content. [1] The soil organic carbon pool is extremely important for soil fertility. [1]

Climate change and the carbon cycle

There is a significant connection between the carbon cycle and climate change. [6] Most greenhouse gases are primarily composed of carbon and they produce an effect where warmer air that is heated by the sun is kept from leaving the atmosphere by forming a barrier in the troposphere. According to the Intergovernmental Panel on Climate Change, greenhouse gasses produced by human activity are the most significant cause of global climate change since the 1950s. [7] Without human interaction, carbon is removed from and reintroduced to soil through a variety of ecosystem processes known as the carbon cycle. Humans have been significantly influencing the global carbon cycle since the Industrial Revolution through various means, such as transportation and agriculture. Through these actions, most of this carbon has moved in one direction, from the lithosphere and biospheres to the atmosphere. By means of fossil fuels and intensive farming, much of the natural carbon in the Earth's pedosphere has been released into the atmosphere, contributing to greenhouse gasses.

Regenerative practices

"Soil works for you if you work for the soil." [5] There are many ways to regenerate soil and improve soil quality, such as land management by conservation agriculture. Agriculture is one of the main factors in the depletion of soil richness. [8] As one historical review put it, "Accelerated soil erosion has plagued the earth since the dawn of settled agriculture, and has been a major issue in the rise and fall of early civilization." [9] Certain agricultural practices can deplete soil of carbon, such as monoculture, [10] where only one type of crop is harvested in a field season after season. This depletes nutrients from the soil because each type of plant has a specific set of nutrients that it requires to grow or that it can fix back into the soil. With a lack of plant diversity, only certain nutrients will be absorbed. Over time, these nutrients will be depleted from the soil. Agroecology is an overarching category of approaches to creating a more sustainable agricultural system and increasing the health of soil. These conservation agricultural practices utilize many techniques and resources to maintain healthy soil. Some examples are cover cropping, crop rotation, reducing soil disturbance, retaining mulch, and integrated nutrient management. [1] These practices have many benefits, including increased carbon sequestration and reducing the use of fossil fuels. [1]

Permaculture (from "permanent" and "agriculture") is a type of conservation agriculture which is a systems thinking approach that seeks to increase the carbon content of soil by utilizing natural patterns and processes. There is a strong emphasis on knowledge of plants, animals, and natural cycles to promote high efficiency food production, decrease reliance on human involvement, and create a sustainable and resilient ecosystem. This can be accomplished through techniques that involve intentional landscaping to increase the efficiency of capturing rainfall into the system or by placing nitrogen fixing plants near nitrogen demanding plants, such as legumes. [3] Utilization of the interconnections of various plants, animals, and processes is a key practice in permaculture. Native plants should be used whenever possible, [3] their roots help water infiltrate deep into the soil. [4] Agroecology also includes the idea of holistic management. This approach stems from the work of Allan Savory who claims that planned grazing can improve soil health and reverse the effects of desertification by increasing biomass. Desertification occurs when the soil carbon content is severely depleted, greatly reducing soil fertility. This critically inhibits plant growth: without plants soil cannot hold water sufficiently, and becomes dry and brittle over time. Permaculture and holistic management are two different methods that focus on regenerating biomass, nutrient content, and biodiversity to the soil. The more biomass in the soil, the more carbon can be sequestered to sustain the natural ecosystem.

There are also many kinds of soil amendments, both organic or inorganic. [3] They promote soil quality in a variety of ways such as: sequestering toxins, balancing the pH of the soil, adding nutrients, and promoting the activity of organisms. [3] The current conditions of the soil will determine which type of amendment and how much to use. [3] Inorganic amendments are generally used for things like improving the texture and structure of the soil, balancing the pH, and limiting the bioavailability of heavy metal toxins. [3] There are two types of inorganic amendments, alkaline and mineral. Some examples of inorganic amendments include wood ash, ground limestone, and red mud. [11] Mineral amendments include gypsum and dredged materials. [3] Organic amendments improve biological activity, water permeability, and soil structure. [4] Mulch, for example, reduces erosion and helps to maintain the temperature of the soil. [3] Compost is rich in organic matter, [4] it is composed of decomposed matter such as food, vegetation, and animal wastes. [3] Adding compost increases the moisture and nutrient content of the soil, and promotes biological activity. Creating compost requires careful management of temperature, the carbon to nitrogen ratio, water, and air. [3] Biochar is an amendment that is full of carbon and is created by pyrolysis, a high temperature decomposition process. [1] Wastes from animals are common soil amendments, usually their manure. The moisture and nutrient content will vary depending on the animal it came from. [3] Human wastes can also be used, like the byproduct biosolids from wastewater facilities. Biosolids can be high in nutrient content, so should be used sparingly. [3]

See also

Related Research Articles

<span class="mw-page-title-main">Soil</span> Mixture of organic matter, minerals, gases, liquids, and organisms that together support life

Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from soil by restricting the former term specifically to displaced soil.

<span class="mw-page-title-main">Crop rotation</span> Agricultural practice of changing crops

Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. This practice reduces the reliance of crops on one set of nutrients, pest and weed pressure, along with the probability of developing resistant pests and weeds.

Soil retrogression and degradation are two regressive evolution processes associated with the loss of equilibrium of a stable soil. Retrogression is primarily due to soil erosion and corresponds to a phenomenon where succession reverts the land to its natural physical state. Degradation is an evolution, different from natural evolution, related to the local climate and vegetation. It is due to the replacement of primary plant communities by the secondary communities. This replacement modifies the humus composition and amount, and affects the formation of the soil. It is directly related to human activity. Soil degradation may also be viewed as any change or ecological disturbance to the soil perceived to be deleterious or undesirable.

<span class="mw-page-title-main">Sustainable agriculture</span> Farming approach that balances environmental, economic and social factors in the long term

Sustainable agriculture is farming in sustainable ways meeting society's present food and textile needs, without compromising the ability for current or future generations to meet their needs. It can be based on an understanding of ecosystem services. There are many methods to increase the sustainability of agriculture. When developing agriculture within sustainable food systems, it is important to develop flexible business process and farming practices. Agriculture has an enormous environmental footprint, playing a significant role in causing climate change, water scarcity, water pollution, land degradation, deforestation and other processes; it is simultaneously causing environmental changes and being impacted by these changes. Sustainable agriculture consists of environment friendly methods of farming that allow the production of crops or livestock without damage to human or natural systems. It involves preventing adverse effects to soil, water, biodiversity, surrounding or downstream resources—as well as to those working or living on the farm or in neighboring areas. Elements of sustainable agriculture can include permaculture, agroforestry, mixed farming, multiple cropping, and crop rotation.

<span class="mw-page-title-main">Topsoil</span> Top layer of soil

Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.

<span class="mw-page-title-main">Soil fertility</span> The ability of a soil to sustain agricultural plant growth

Soil fertility refers to the ability of soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality. It also refers to the soil's ability to supply plant/crop nutrients in the right quantities and qualities over a sustained period of time. A fertile soil has the following properties:

<span class="mw-page-title-main">Organic fertilizer</span> Fertilizer developed from natural processes

Organic fertilizers are fertilizers that are naturally produced. Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include all animal waste including meat processing waste, manure, slurry, and guano; plus plant based fertilizers such as compost; and biosolids. Inorganic "organic fertilizers" include minerals and ash. The organic-mess refers to the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture, not whether the fertilizer consists of organic compounds.

<span class="mw-page-title-main">Agricultural soil science</span> Branch of soil science

Agricultural soil science is a branch of soil science that deals with the study of edaphic conditions as they relate to the production of food and fiber. In this context, it is also a constituent of the field of agronomy and is thus also described as soil agronomy.

Soil chemistry is the study of the chemical characteristics of soil. Soil chemistry is affected by mineral composition, organic matter and environmental factors. In the early 1870s a consulting chemist to the Royal Agricultural Society in England, named J. Thomas Way, performed many experiments on how soils exchange ions, and is considered the father of soil chemistry. Other scientists who contributed to this branch of ecology include Edmund Ruffin, and Linus Pauling.

<span class="mw-page-title-main">Phosphorus cycle</span> Biogeochemical movement

The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth. The production of phosphine gas occurs in only specialized, local conditions. Therefore, the phosphorus cycle should be viewed from whole Earth system and then specifically focused on the cycle in terrestrial and aquatic systems.

<span class="mw-page-title-main">Soil respiration</span> Chemical process produced by soil and the organisms within it

Soil respiration refers to the production of carbon dioxide when soil organisms respire. This includes respiration of plant roots, the rhizosphere, microbes and fauna.

Soil organic matter (SOM) is the organic matter component of soil, consisting of plant and animal detritus at various stages of decomposition, cells and tissues of soil microbes, and substances that soil microbes synthesize. SOM provides numerous benefits to the physical and chemical properties of soil and its capacity to provide regulatory ecosystem services. SOM is especially critical for soil functions and quality.

<span class="mw-page-title-main">Soil carbon</span> Solid carbon stored in global soils

Soil carbon is the solid carbon stored in global soils. This includes both soil organic matter and inorganic carbon as carbonate minerals. It is vital to the soil capacity in our ecosystem. Soil carbon is a carbon sink in regard to the global carbon cycle, playing a role in biogeochemistry, climate change mitigation, and constructing global climate models. Natural variation such as organisms and time has affected the management of carbon in the soils. The major influence has been that of human activities which has caused a massive loss of soil organic carbon. An example of human activity includes fire which destroys the top layer of the soil and the soil therefore get exposed to excessive oxidation.

Soil biodiversity refers to the relationship of soil to biodiversity and to aspects of the soil that can be managed in relative to biodiversity. Soil biodiversity relates to some catchment management considerations.

The environmental impact of agriculture is the effect that different farming practices have on the ecosystems around them, and how those effects can be traced back to those practices. The environmental impact of agriculture varies widely based on practices employed by farmers and by the scale of practice. Farming communities that try to reduce environmental impacts through modifying their practices will adopt sustainable agriculture practices. The negative impact of agriculture is an old issue that remains a concern even as experts design innovative means to reduce destruction and enhance eco-efficiency. Though some pastoralism is environmentally positive, modern animal agriculture practices tend to be more environmentally destructive than agricultural practices focused on fruits, vegetables and other biomass. The emissions of ammonia from cattle waste continue to raise concerns over environmental pollution.

<span class="mw-page-title-main">Agricultural pollution</span> Type of pollution caused by agriculture

Agricultural pollution refers to biotic and abiotic byproducts of farming practices that result in contamination or degradation of the environment and surrounding ecosystems, and/or cause injury to humans and their economic interests. The pollution may come from a variety of sources, ranging from point source water pollution to more diffuse, landscape-level causes, also known as non-point source pollution and air pollution. Once in the environment these pollutants can have both direct effects in surrounding ecosystems, i.e. killing local wildlife or contaminating drinking water, and downstream effects such as dead zones caused by agricultural runoff is concentrated in large water bodies.

Soil management is the application of operations, practices, and treatments to protect soil and enhance its performance. It includes soil conservation, soil amendment, and optimal soil health. In agriculture, some amount of soil management is needed both in nonorganic and organic types to prevent agricultural land from becoming poorly productive over decades. Organic farming in particular emphasizes optimal soil management, because it uses soil health as the exclusive or nearly exclusive source of its fertilization and pest control.

<span class="mw-page-title-main">Regenerative agriculture</span> Conservation and rehabilitation approach to food and farming systems

Regenerative agriculture is a conservation and rehabilitation approach to food and farming systems. It focuses on topsoil regeneration, increasing biodiversity, improving the water cycle, enhancing ecosystem services, supporting biosequestration, increasing resilience to climate change, and strengthening the health and vitality of farm soil.

<span class="mw-page-title-main">Carbon farming</span> Agricultural methods that capture carbon

Carbon farming is a name for a variety of agricultural methods aimed at sequestering atmospheric carbon into the soil and in crop roots, wood and leaves. The aim of carbon farming is to increase the rate at which carbon is sequestered into soil and plant material with the goal of creating a net loss of carbon from the atmosphere. Increasing a soil's organic matter content can aid plant growth, increase total carbon content, improve soil water retention capacity and reduce fertilizer use. Carbon farming is one component of climate smart agriculture.

Soil carbon sponge is porous, well-aggregated soil in good health, better able to absorb and retain water. Australian microbiologist and climatologist, Walter Jehne, articulated the concept of the soil carbon sponge in his 2017 paper, Regenerate Earth, connecting soil carbon with a restored water cycle able induce planetary cooling through evaporative cooling and higher reflectance of denser green vegetation. Cooling from increased cloud formation is another benefit of soil regeneration anticipated by Jehne.

References

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