Soil regeneration

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.

"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]

• Carbon cycle
• Climate change
• Environmental soil science
• Land restoration
• Regenerative agriculture
• Soil carbon feedback