Actinomycetes. A type of soil bacteria that grow in rootlike colonies that resemble fungal strands (hyphae). They are good at breaking down resistant organic materials like cellulose, give soils their characteristic earthy odor, and are the source of many antibiotics used in medicine.
Aggregate. A discreet package of soil that is formed of the individual particles of sand, silt, clay, and organic matter. When a soil is well aggregated, there are channels or pore spaces between the aggregates that allow water, air, and soil organisms to move more freely through the soil.
Amendment. A material that is added to the soil to improve its fertility, reaction (acidity/alkalinity), or physical characteristics.
Anthelmintics. Naturally occurring or synthetic materials that inhibit or kill internal parasites.
Bedded pack. A system in which animals are fed and bedded in the same area for an extended time so that a mound of bedding, manure, and waste feed accumulates.
Beneficial elements. Chemical elements that may be required by some, but not all, plants, or that help plants to grow better, even if they aren’t absolutely necessary for plants to survive.
Biological nitrogen fixation. The process of converting atmospheric N into a compound that plants can take up and utilize.
Carbonaceous (“brown”) material. A type of organic matter with a very high carbon content in relation to the amount of nitrogen it contains. Examples: sawdust, straw, corn stalks, rice hulls, and wood chips.
Compost barns. Livestock housing structures that use a layer of carbonaceous bedding to absorb manure, and that require daily mechanical mixing of the bedding to actively compost the material while it’s still being used as bedding.
Composting. An aerobic decomposition process that usually implies frequent mixing/turning to generate high temperatures.
Cover crops. Crops that are grown exclusively or primarily as a source of fresh organic matter for the soil rather than to be harvested as a crop for human food or livestock feed.
Crown. The part of a plant where the stem and roots merge.
Daily haul system. A manure handling system that is accomplished by collecting and hauling each day’s manure production out to a field or pasture for spreading.
Essential elements. Chemical elements that are required by all plants for their survival.
Fertilizer credit. Credit for various plant nutrients that can be supplied by materials other than fertilizers.
Glyphosate. A specific formulation of nonselective, synthetic, systemic herbicide that is widely used in conventional agriculture and horticulture.
Grass tetany (hypomagnesemia). A metabolic disorder of cattle characterized by low levels of magnesium in the blood. It is caused by the animal consuming forages that have very high potassium and/or very low magnesium levels. It is also called grass staggers.
Green manure crops. Leguminous cover crops that are grown to provide high amounts of nitrogen to crops that will be grown next in a rotation.
Gypsum. Hydrated calcium sulfate. Often used as a soil amendment, especially in organic farming systems, as a source of sulfur and calcium and to improve soil aggregation/tilth.
Humanure. Human excrement.
Humus. The type of organic matter that is left in the soil after all soil organisms have digested the usable fractions of the material. It has very small particle size and is resistant to further breakdown in the soil. It helps bind soil aggegates together and enhances the ability of the soil to hold onto and exchange plant nutrients.
Hydrogen sulfide gas. (H2S). A poisonous gas that is released from organic matter that decays under anaerobic conditions.
Incorporate. To till or mix into the soil.
Ions. Atoms or molecules that carry an electrical charge from having an excess or deficiency of electrons.
Legumes. Plants in the pea or bean family. Other examples include alfalfa, clovers, vetches, lupines, and trees like locusts and acacias.
Macronutrients. Plant nutrients not supplied directly from air or water that plants need in very large amounts. Examples: nitrogen, phosphorus, and potassium.
Manure. The dung (feces) and urine, mostly of farm animals, with or without other materials used as bedding.
Micronutrients. Chemical elements that are required by plants in very small amounts, such as zinc, copper, boron, manganese, iron, chlorine, nickel, and molybdenum.
Milk fever. A metabolic disorder of livestock caused by a deficiency of calcium in the blood.
National Organic Program (NOP). A set of rules governing the legal requirements of organic agriculture in the United States; administered by the U.S. Department of Agriculture.
Night soil. A traditional term for human excrement applied to agricultural lands.
Nitrogenous “green” material. Organic matter characterized by a relatively high proportion of nitrogen in relation to the amount of carbon it contains. Examples include fresh grass clippings or high-quality hay, alfalfa pellets, soybean meal, and most manures.
Peds. The scientific term for soil aggregates.
Phosphate (P2O5). The oxide form of phosphorus that is traditionally used in fertilizer analysis and fertility recommendations.
Pigerator. A system that uses hogs to aerate and loosen a bedded pack manure storage area.
Potash (K2O). The oxide form of potassium that is traditionally used in fertilizer analysis and fertility recommendations.
Rhyzobial bacteria. A type of bacteria that are associated with most leguminous plants. They contain an enzyme called nitrogenase that allows them to convert inert nitrogen gas from the atmosphere into the forms used in their bodies. They also provide plant-available nitrogen to their host plants and other organisms living in that plant community.
Rock phosphate. A mined rock product that contains relatively high levels of phosphorus; commonly used as a phosphorus fertilizer in organic crop production.
Rotational grazing. A controlled grazing system that relies on grazing cattle in discreet paddocks for a short time. After that forage is grazed down to the appropriate height, the cattle are moved to the next paddock, and they aren’t allowed to regraze the area until it’s rested enough for the plants to be at their prime condition again.
Slurry. A semisolid mix of manure, bedding, and water.
Static pile. A manure pile that is undisturbed during storage; it decomposes anaerobically over a long time.
Top-dress. To apply fertilizer or manure to the surface of the soil without incorporating it.
Vermicomposting. A system of composting manure that relies on the activity of earthworms managed specifically for that purpose.