Glossary – water quality and soil health terms

Bioreactor: A trench filled with wood chips or other organic material designed to filter and break down excess nutrients in field runoff water before it reaches nearby waterways.

Conservation drainage: Agricultural water drainage systems designed not only to control excess water runoff but also to minimize nutrient loss from fields, improving water quality.

Conservation tillage: Farming methods that reduce the frequency or intensity of soil tillage, helping prevent soil erosion and retain soil moisture and nutrients.

Cover crops: Plants grown between plantings of main (cash) crops to improve soil health by preventing erosion, reducing nutrient loss, and adding organic matter to the soil.

Drainage water management (DWM): A practice where water drainage systems are managed to control water flow, helping retain nutrients in the soil and improve water quality.

Drinking water: Water that is safe for human consumption, most often following a water treatment process.

Edge-of-field practice: Conservation practices applied at the edges of crop fields to reduce nutrient runoff and protect nearby water sources.

Extended crop rotation: A farming practice that includes a broader variety of crops grown in sequence over several years to improve soil health, while also reducing pests and disease cycles.

Grassed waterway: A strip of grassy vegetation planted in areas of fields where water naturally flows, reducing erosion and filtering out pollutants before they reach water sources.

In-field practice: Conservation methods applied directly within crop or pasture fields, such as cover crops or precision nutrient management, to improve soil health and water quality.

Manure management plan: A plan for applying animal manure to fields in a way that provides necessary nutrients to crops while minimizing nutrient runoff into waterways.

Native prairie: Preserved or restored areas featuring native grasses and wildflowers that once covered prairies. Strategically-placed prairies, or prairie strips, can support biodiversity and enhance soil and water quality.

No-till: A farming method where the soil is not plowed between crop seasons, helping prevent erosion and preserving soil structure and health.

Nutrient (in crops): Elements essential for plant growth, such as nitrogen (N), phosphorus (P), and potassium (K), often applied to fields as fertilizer.

Nutrient loss (from soil): The movement of nutrients like nitrogen (N) and phosphorus (P) from the soil into waterways, where they can cause pollution.

Nutrient management: Strategies for applying fertilizers and other nutrients to crops in a way that minimizes waste while maximizing crop growth.

Nutrient reduction (general): Efforts to decrease the amount of nutrients entering waterways from agricultural and urban sources to improve water quality.

Outcome: The measurable impact or result of conservation practices, such as improved water quality, enhanced soil health, or reduced greenhouse gas emissions.

Oxbow: A type of wetland formed by a cut-off bend of a river or stream that helps filter nutrients from runoff before they enter main water channels.

Practice (on-farm conservation): A specific technique or tactic implemented to achieve conservation goals, such as reduced nutrient runoff or better soil health.

Prairie strip: Strips of native prairie plants incorporated into fields to reduce soil erosion, improve water quality, and support native wildlife.

Precision nutrient application: The use of technology to apply crop nutrients at the right place, time, and amount, reducing waste (and costs) as well as environmental impact.

Restoration (practice): Actions taken to return land or water areas to their natural, healthy condition in order to improve biodiversity and ecosystem function.

Saturated buffer: A conservation practice where drainage water is redirected to a vegetated area along a field edge, allowing plants to absorb excess nutrients from field runoff.

Small grains: Crops like oats, barley, and wheat that are often grown as part of a diverse crop rotation to improve soil health and reduce pest pressure. They can be used as cover crops, pasture crops, or as cash crops, depending on the operation.

Soil: The upper layer of earth where plants grow—a mixture of organic matter, minerals, and microorganisms vital for agriculture and the environment.

Soil health: The condition of soil, including its structure, nutrient content, and biological activity, which is essential for supporting plant life and ecosystems.

Stream buffer: A vegetated area along a stream that helps filter runoff, preventing erosion and reducing nutrient pollution in waterways.

Terrace: A raised embankment or stepped structure built on sloped fields to reduce soil erosion and capture water for crops.

Wastewater: Used water from homes, businesses, or agricultural processes that must be treated before it can be safely released back into the environment.

Water quality: The measure of water’s suitability for use, based on factors like clarity, nutrient levels, and presence of pollutants.

Water quality wetland: Wetlands designed or restored to improve water quality by trapping sediments, nutrients, and pollutants from runoff water before they reach rivers or lakes.

Water treatment: Processes used to remove impurities from water, making it safe for drinking, agriculture, or other uses.

Waterbody: Any significant accumulation of water, like rivers, lakes, or ponds, that serves as a habitat and a resource for ecosystems and communities.

Batch and Build: A strategy used in water quality improvement where multiple conservation practices are installed at once in a specific area, creating high-impact benefit downstream.

BMP (Best Management Practice): A practice or measure that reduces environmental impacts, often used in agriculture or land development to protect water quality.

Conservation Agronomist: A specialist who works with farmers to promote agricultural practices that enhance soil health, reduce erosion, and improve water quality.

Cost share: Financial assistance programs that cover a portion of the cost for conservation practices, making it more affordable for farmers and landowners to implement them.

Watershed coordinator: A professional who manages efforts to improve water quality across a watershed, coordinating with communities and area stakeholders

RCPP: Regional Conservation Partnership Program (NRCS funding program) EQIP: Environmental Quality Incentives Program (under USDA)

ACEP: Agricultural Conservation Easement Program (under USDA)

WQI: Water Quality Initiative (under Iowa Department of Agriculture and Land Stewardship)

USDA: U.S. Department of Agriculture

NRCS: Natural Resources Conservation Service (under USDA)

SWCD: Soil and Water Conservation District

Algae: Simple aquatic organisms that grow in water and can multiply quickly in nutrient-rich conditions, sometimes leading to harmful algal blooms.

Denitrification: The natural process where bacteria convert nitrate in the soil or water into nitrogen gas, reducing nutrient pollution in water bodies.

Drought: A prolonged period of dry conditions with below-average rainfall, affecting water availability, agriculture, and ecosystems.

Ecosystem: A community of living organisms interacting with each other and their physical environment, creating a balanced, interconnected system.

Flow: The movement of water through a river, stream, or other water body, measured by volume over time.

Groundwater: Water stored in the soil and rock below the Earth’s surface, a major source of drinking water and irrigation.

Gulf of Mexico Hypoxia (Dead) Zone: An area in the Gulf of Mexico with low oxygen levels due to nutrient runoff, leading to a “dead zone” where marine life struggles to survive.

HUC (Hydrologic Unit Code): A system for defining and organizing watershed boundaries, maintained by the U.S. Geological Survey and used for mapping watersheds at a local, regional, national, or international scale.

Hydrologic unit: A geographic area from which water drains to a specific water body, such as a creek, river, or lake used to define watershed boundaries. Hydrologic units can define watersheds large and small, from a local creek to the whole Mississippi River Basin.

Hydrology: The study of water’s movement, distribution, and quality in the Earth’s atmosphere, surface, and groundwater systems.

Irrigation: The application of water to crops to supplement rainfall and support plant growth, especially in drier regions.

Lead (Pb): A common, toxic heavy metal that can contaminate water and soil, posing health risks to humans and wildlife in excessive amounts.

Legacy sediment: Sediments that have accumulated in water bodies from past land-use practices, often with lingering effects on water quality and ecosystems.

Load: The total amount of a pollutant or substance, like nutrients or sediments, carried by water from a specific area over time.

Microplastics: Tiny plastic particles, often from broken-down plastic products, that can contaminate water and harm aquatic life.

Mississippi River Basin: The large drainage area in the central United States that feeds water into the Mississippi River – including tributaries like the Missouri and Ohio rivers -, and ultimately drains into the northern Gulf of Mexico.

Non-point source: Pollution that comes from widespread, diffuse sources like farm fields or urban areas, rather than a single, specific spot.

Nutrient load: The amount of nutrients, like nitrogen and phosphorus, entering water bodies from sources such as agriculture or wastewater.

Per- and polyfluoroalkyl substances (PFAS): A group of synthetic chemicals resistant to degradation, often called “forever chemicals,” that can contaminate water and pose health risks.

Point-source: Pollution that originates from a specific, identifiable source, like a factory pipe or wastewater treatment plant.

Riparian zone: The area of land along rivers and streams, which provides habitat, filters runoff, and stabilizes stream banks.

Runoff: Water from rain, snowmelt, or irrigation that flows over land surfaces, often carrying pollutants into nearby water bodies.

Sedimentation: The process where particles settle out of water, collecting in areas like riverbeds or lakes, which can impact water quality and habitats.

Source water: Water from natural sources such as rivers, lakes, or aquifers used for drinking, irrigation, or other purposes.

Stream mouth: The point where a stream or river flows into a larger body of water, such as a lake or ocean.

Stream source: The origin(s) of a stream or river, often from a spring, lake, or snowmelt, where water begins its downhill course.

Water contaminant: A substance that pollutes water, such as PFAS, lead, excess nutrients, or microplastics, making it unsafe for use.

Water cycle: The continuous process where water circulates between the Earth’s surface and atmosphere, including precipitation, evaporation, and condensation.

Water monitoring: The regular observation and testing of water quality to track pollutants, water levels, and ecosystem health.

Water table: The level below the ground where soil and rock are fully saturated with water, marking the top of groundwater.

Watershed: An area of land where all precipitation and runoff drains to a common water body, like a river, lake, or ocean.

Aggregate: Clusters of soil particles bound together, important for soil structure, aeration, and water infiltration.

Aggregate stability: The ability of soil aggregates, or clumps, to resist breaking apart, which influences soil structure and health.

Baseline: The initial condition or starting point used for comparison to measure changes in soil health, water quality, or other factors.

Biological diversity: The variety of life forms within an ecosystem, which supports resilience and ecological balance.

Carbon (C): An essential element for life, forming the basis of organic matter in soil and contributing to plant growth and soil health.

Erosion: The process where soil or rock is worn away by wind, water, or human activity, often leading to land degradation.

Humus (a.k.a Compost): The organic component of soil formed from decomposed plant and animal material, enriching soil fertility.

Infiltration or Infiltration Rate: The process by which water enters soil, affecting soil moisture, plant growth, and groundwater recharge.

Microbe: Microscopic organisms in soil, such as bacteria and fungi, that play vital roles in nutrient cycling and soil health.

Nitrogen/Nitrate (N): A vital nutrient for plants, commonly added as fertilizer but can lead to pollution if it enters water systems.

Nutrients: Substances essential for plants, including nitrogen, phosphorus, and potassium.

Organic matter: Decomposed plant and animal materials in soil, providing nutrients, improving structure, and supporting microbes.

Phosphorus/Phosphate (P): A key nutrient for plant growth that can cause water pollution when it enters waterways from agricultural runoff.

Potassium (K): An essential nutrient for plant health, often applied to soils to support crop growth and quality.

Regenerative agriculture: Farming practices focused on improving soil health, biodiversity, and ecosystem resilience to benefit the environment.

Slake test: A simple test to assess soil aggregate stability, where soil clumps are immersed in water to observe how well they hold together.

Slope (landscape): The incline or gradient of the land surface, influencing erosion risk, water flow, and drainage.

Soil disturbance: Any action, like plowing or tilling, that disrupts soil structure, potentially affecting its health and stability.

Soil health: A measure of soil’s condition, including its ability to support plants, retain water, cycle nutrients, and resist erosion.

Soil profile: The vertical section of soil layers, from topsoil to subsoil, each layer having unique properties and functions.

Soil testing: Analyzing soil to measure nutrient levels, pH, and organic matter, helping inform crop and soil management.

Topography: The arrangement of natural and artificial features on the landscape, influencing water flow, erosion, and land use.

Additionality (carbon credits): The concept that carbon reduction projects must provide emission savings that would not have occurred without the carbon market, ensuring a true climate benefit.

Anthropogenic: Originating from human activity, especially referring to environmental changes caused by greenhouse gas emissions from industry, agriculture, or transportation.

Avoidance (emissions): Actions taken to prevent emissions from being released in the first place, such as conserving forests to prevent deforestation emissions.

Cap-and-trade (program type): A system where a government limits (or caps) total greenhouse gas emissions, issuing permits (credits) that companies can trade. Those that reduce emissions can sell permits, creating financial incentives to cut emissions.

Carbon dioxide (CO₂): A naturally occurring greenhouse gas and a major contributor to climate change when released in excess by human activity, such as large-scale fossil fuel use.

Carbon footprint: The total amount of greenhouse gasses added to the earth’s atmosphere by human activities, directly and indirectly. Typically measured in tons per year.

Carbon Intensity (CI) Score: A measure of how much greenhouse gas is emitted in an entire production and delivery process for a good – a measure of one’s carbon footprint.

Carbon market: An economic system that enables the buying and selling of carbon credits, helping to fund projects that reduce or remove carbon emissions.

Carbon market program: A structured system that allows and incentivizes companies or organizations to buy and sell carbon credits in a market, with a goal of lowering overall greenhouse gas emissions.

Carbon offset(ting): The process of compensating for one’s emissions by purchasing carbon credits that fund activities to reduce or capture emissions elsewhere.

Carbon sink: Natural or artificial systems, like forests, oceans, or soil, that absorb and store more carbon dioxide than they release, helping reduce CO₂ levels in the air.

Carbon source: Any activity or process that releases carbon dioxide into the atmosphere, such as burning fossil fuels.

Climate change: Long-term shifts in temperatures, weather patterns, and global climate. Occurs naturally, but the term is used mainly to describe climate change caused by greenhouse gas emissions from human activities.

Decarbonization: The process of reducing CO₂ emissions by shifting to cleaner energy sources and more sustainable practices in various industries.

Ecosystem services: Benefits provided by earth’s ecosystems, such as water, plant pollination, and climate regulation processes, which support life and human well-being.

Emission: The release of gasses, like carbon dioxide, methane, and nitrous oxide into the atmosphere, contributing to the greenhouse effect, which drives climate change.

Fluorinated gasses (F-gasses): Synthetic greenhouse gasses used in industrial applications, such as refrigeration, that are potent and long-lasting in the atmosphere.

Global carbon cycle: The natural circulation of carbon among the earth’s atmosphere, oceans, soil, and living organisms – a major factor in earth’s long-term climate.

Global warming: The increase in Earth’s average surface temperature due to rising levels of greenhouse gasses in the atmosphere.

Greenhouse effect: The warming of Earth’s surface as greenhouse gasses trap heat from the sun, essential for life but intensified by human activities.

Greenhouse gas (GHG): Gasses, such as carbon dioxide, methane, and nitrous oxide, that trap heat in the atmosphere and contribute to climate change.

Greenhouse Gas Technical Assistance Provider and Third-Party Verifier Program: A government program that provides support and certification for organizations developing or verifying greenhouse gas reduction projects.

Intergovernmental Panel on Climate Change (IPCC): An international body of scientists that assesses climate change science, impacts, and possible solutions, providing guidance for global climate policy.

Leakage: When a reduction in emissions in one area inadvertently causes emissions to increase elsewhere, reducing the overall climate benefit.

Methane (CH₄): A powerful greenhouse gas with a much higher heat-trapping potential than carbon dioxide, released from sources like livestock, natural gas, and landfills.

Net Zero (goal): A state where an entity’s greenhouse gas emissions are balanced by carbon removal efforts, resulting in no net increase in atmospheric emissions.

Nitrous oxide (N₂O): A potent greenhouse gas released from agricultural practices, industrial activities, and fuel combustion, with a strong warming effect.

Permanence (in carbon credits): The durability of carbon storage, ensuring that emissions reductions or carbon removals are sustained over a long period.

Realness (carbon credits): The assurance that emission reductions represented by a carbon credit are genuine and based on verified, measurable activities.

Reductions (emissions): Actions taken to decrease the amount of greenhouse gasses released into the atmosphere, helping mitigate climate change.

Sequestration (of GHGs): The capture and long-term storage of greenhouse gasses, such as carbon dioxide, in natural systems like forests or engineered solutions.

Technical Assistance (TA) provider: An organization that helps project developers design, implement, and verify carbon reduction projects.

Third-Party Verifier: An independent organization that verifies carbon credit projects to ensure they meet established standards and deliver real emission reductions.

Verification: The process of confirming that a carbon project’s reported emission reductions are accurate, ensuring credits represent real climate benefits.

Voluntary carbon market: A system where businesses or individuals buy carbon credits on a voluntary basis to offset emissions or meet corporate sustainability goals.