Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing, rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth).
The University of California, Merced is a public land-grant research university in Merced, California, United States. It is one of the ten campuses in the University of California (UC) system. Established in 2005, UC Merced is the newest campus within the UC system. The primary campus is located around five miles north of Merced and sits adjacent to Lake Yosemite. The main campus is around 1,026 acres in size. Large swaths of protected natural grasslands surround the university.
No-till farming is an agricultural technique for growing crops or pasture without disturbing the soil through tillage. No-till farming decreases the amount of soil erosion tillage causes in certain soils, especially in sandy and dry soils on sloping terrain. Other possible benefits include an increase in the amount of water that infiltrates into the soil, soil retention of organic matter, and nutrient cycling. These methods may increase the amount and variety of life in and on the soil. While conventional no-tillage systems use herbicides to control weeds, organic systems use a combination of strategies, such as planting cover crops as mulch to suppress weeds.
Tilth is a physical condition of soil, especially in relation to its suitability for planting or growing a crop. Factors that determine tilth include the formation and stability of aggregated soil particles, moisture content, degree of aeration, soil biota, rate of water infiltration and drainage. Tilth can change rapidly, depending on environmental factors, lsuch as changes in moisture, tillage and soil amendments. The objective of tillage is to improve tilth, thereby increasing crop production; in the long term, however, conventional tillage, especially plowing, often has the opposite effect, causing the soil carbon sponge to oxidize, break down and become compacted.
Fire ecology is a scientific discipline concerned with the effects of fire on natural ecosystems. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments use fire to germinate, establish, or to reproduce. Wildfire suppression not only endangers these species, but also the animals that depend upon them.
Smouldering or smoldering is the slow, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase fuel. Many solid materials can sustain a smouldering reaction, including coal, cellulose, wood, cotton, tobacco, cannabis, peat, plant litter, humus, synthetic foams, charring polymers including polyurethane foam and some types of dust. Common examples of smouldering phenomena are the initiation of residential fires on upholstered furniture by weak heat sources, and the persistent combustion of biomass behind the flaming front of wildfires.
Biochar is charcoal, sometimes modified, that is intended for organic use, as in soil. It is the lightweight black remnants remaining after the pyrolysis of biomass, consisting of carbon and ashes; and is a form of charcoal. Despite its name, immediately following production biochar is sterile and only gains biological life following assisted or incidental exposure to biota.
In soil science, mineralization is the decomposition of the chemical compounds in organic matter, by which the nutrients in those compounds are released in soluble inorganic forms that may be available to plants. Mineralization is the opposite of immobilization.
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. Microorganisms play an important role in breaking down carbon in the soil. Changes in their activity due to rising temperatures could possibly influence and even contribute to climate change. Human activities have caused a massive loss of soil organic carbon. For example, anthropogenic fires destroy the top layer of the soil, exposing soil to excessive oxidation.
Carbon dioxide removal (CDR) is a process in which carbon dioxide is removed from the atmosphere by deliberate human activities and durably stored in geological, terrestrial, or ocean reservoirs, or in products. This process is also known as carbon removal, greenhouse gas removal or negative emissions. CDR is more and more often integrated into climate policy, as an element of climate change mitigation strategies. Achieving net zero emissions will require first and foremost deep and sustained cuts in emissions, and then—in addition—the use of CDR. In the future, CDR may be able to counterbalance emissions that are technically difficult to eliminate, such as some agricultural and industrial emissions.
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. 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.
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.
David Alan Laird is a professor at Iowa State University, Department of Agronomy, Ames, Iowa. Throughout his career as a soil scientist, he made many contributions to clay mineralogy, including developing a model describing the relationship between cation selectivity and the extent of crystalline swelling in expanding 2:1 phyllosilicates. Other work demonstrated the effects of ionic strength and cation charge on the breakup and formation of smectitic quasicrystals and the principle of cation demixing which lent great insight into understanding clay flocculation. Investigations in organic matter interactions with clay minerals led to the development of the idea of dual mode bonding in which amphipathic molecules interact with substrates by both hydrophobic-hydrophobic and hydrophilic-hydrophilic interactions. Laird et al. (2008) showed that smectites, a class of clay minerals found in soil, can adsorb tremendous amounts of organic materials and, hence, strongly influence the transport and bioavailability of organic materials including pesticides applied to the soil. In a study published in 2003, Gonzalez and Laird showed that new carbon derived from decomposing plant material tends to preferentially sorb to the fine clay subfraction of soil. Further work demonstrated that the coarse clay fraction had the greatest carbon to nitrogen ratio, greatest minimum residence time in the soil based on 14C radioisotope dating, and contained carbon most recalcitrant to microbial digestion. Collectively many of Dr. Laird's contributions to soil science have provided insight into understanding soil organic matter and clay interactions and, thus, the genesis of soil peds from the molecular viewpoint.
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.
Marilyn L. Fogel was an American geo-ecologist and Professor of Geo-ecology at UC Riverside in Riverside, California. She is known for her research using stable isotope mass spectrometry to study a variety of subjects including ancient climates, biogeochemical cycles, animal behavior, ecology, and astrobiology. Fogel served in many leadership roles, including Program Director at the National Science Foundation in geobiology and low-temperature geochemistry.
Carbon farming is a set of agricultural methods that aim to store carbon in the soil, crop roots, wood and leaves. The technical term for this is carbon sequestration. The overall goal of carbon farming is to create a net loss of carbon from the atmosphere. This is done by increasing the rate at which carbon is sequestered into soil and plant material. One option is to increase the soil's organic matter content. This can also aid plant growth, improve soil water retention capacity and reduce fertilizer use. Sustainable forest management is another tool that is used in carbon farming. Carbon farming is one component of climate-smart agriculture. It is also one way to remove carbon dioxide from the atmosphere.
Asmeret Asefaw Berhe is a soil biogeochemist and political ecologist who served as Director of the Office of Science at the US Department of Energy from 2022 to 2024. She is a Professor of Soil Biogeochemistry and the Ted and Jan Falasco Chair in Earth Sciences and Geology in the Department of Life and Environmental Sciences; University of California, Merced. Her research group works to understand how soil helps regulate the Earth's climate.
Caroline Masiello is a biogeochemist who develops tools to better understand the cycling and fate of globally relevant elemental cycles. She is a professor at Rice University in the Department of Earth, Environmental and Planetary Sciences and holds joint appointments in the Chemistry and Biochemistry Departments. Masiello was elected as a Fellow of the Geological Society of America in 2017. She currently leads an interdisciplinary team of scientists who are developing microbial sensors for earth system science.
Jennifer Harden is geologist known for her research on soils, particularly tracking changes in soil profiles over time and the role of soil systems in carbon and nitrogen cycling.
Bala Chaudhary is an American soil ecologist. She is an Associate Professor of Environmental Studies at Dartmouth College.
