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Glossary Acr~foot The volume of irrigation water that would cover one acre to a depth of one foot. Agricultural resource base The soil, water, climate, and other natural resources necessary to produce a crop. Agricultural Stabilization and Conservation Service {ASCS' A U.S. De- partment of Agriculture (USDA) agency responsible for administering farm price and income support programs as weD as some conservation and forestry cost-sharing programs; local offices are maintained in nearly aD farming counties. Allelopathy The suppression of the growth of one plant species by an- other. Band application A method of applying fertilizer in bands near plant rows where the fertilizer will be more efficiently used rather than ap- plying it in an application to the entire soil surface. Base acres The acres on a farm that are eligible for federal program pay- ments. Base acres for each year are calculated as the average number of acres enrobed in a specific commodity program during the previous 5 years. Biomass Matter of biological origin; for example, the living and decaying matter in soil as opposed to the inorganic mineral components. Bureau of Reclamation A federal agency responsible for building dams and canals and providing water to local water districts. The districts then seD the water to agricultural producers. Cash grains Grains commonly produced for sale, such as corn, oats, and wheat, as opposed to hay and other grains that are grown principally as feed for animals or seed. 419

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420 GLOSSARY Center pivot irrigation An irrigation system that pumps groundwater from a well in the center of a field through a long pipe, elevated on wheels, that pivots around the well and irrigates the field in a large circular pattern. Commodity Credit Corporation {CCC, A wholly owned government cor- poration created to stabilize, support, and protect farm income and commodity prices. The CCC and the ASCS administer the federal farm programs. Commodity price and income support programs Federal programs de- signed to support crop prices and farm income. These programs in- clude all commodity-specific programs (such as the corn program) un- der which commodity price support levels are established, set asides are determined, direct payments and nonrecourse crop loans are made to farmers, and agricultural land is diverted from production through paid land diversions and other provisions. Conservation Reserve Program [CRP} A program authorized under the Food Security Act of 1985 that allows up to 45 million acres of highly erodible land to be placed into a 10-year reserve. Land in the reserve must be under grass or tree cover to protect it from erosion. It is not allowed to be used for hay production or livestock grazing. Cover crop A crop grown for its value as ground cover to reduce soil erosion, retain soil moisture, provide nitrogen for subsequent crops, control pests, improve soil texture, increase organic matter, or comply with erosion control requirements of federal commodity programs. Commonly used cover crops include the clovers, vetch, alfalfa, and rye. Crop residues The remains of crop plants after harvest. Residues are fre- quently left in fields to supply organic matter to the soil and help cover the soil surface, which reduces erosion losses. Crop rotation The successive planting of different crops in the same field over a period of years. Farmers using rotations typically plant a part of their land to each crop in the rotation. A common 4-year rotation is corn-soybeans-oats-alfalfa. Crop yield The amount of a crop harvested, commonly expressed in bush- els or other units per acre. Cross-compliance A provision of the Food Security Act of 1985 designed to control the expansion of a farmer's base acres and limit federal payments for the production of program crops. In general, cross-com- pliance stipulates that to receive any benefits from an established crop acreage base, the farmer may not exceed his or her acreage base for any other program crop. Cultivation To mechanically loosen or break up soil between the rows of growing crops, uproot weeds, and aerate the soil. Soil around crops is generally cultivated one to three times per season, depending on soil type, weather, weed pressure, and herbicide use. Cultural pest control Pest control practices that generally refer to physical or mechanical changes in an agricultural method. These may include clearing crop residue soon after harvest, crop rotations, clearing weeds

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GLOSSARY 421 from the field borders, changes in irrigation, or altering the timing or way of planting. Deficiency payment The per unit of production (bushel or pound) pay- ment that is made directly to producers enrobed in the commodity programs. It is usually calculated as the difference between the target price and the loan rate or market price, whichever is higher. Denitrification ~ - ~ The bacterial reduction of nitrate to nitrogen gas (NO2), nitrous oxide (N'O), and nitric oxide (NO). Denitrification occurs under . . , ~ . ~ . . . ~ ~ . . ~ ~ .. ~ ~ . ~ anaerobic conditions and results in loss of available nitrogen from the soil. Direct payments Payments made by the federal government to agricul- . . . .. . . .. . . tural producers enrolled in commodity programs. A deficiency pay- ment is the most common form of a direct payment. Deficiency pay- ments can be made in cash or in certificates entitling the producer to receive an equivalent cash value of crops from the CCC based on the current loan rate. Diversion payments A per acre payment available in certain years as an option to producers enrolled in commodity programs who divert {and from production of a program crop in addition to the acreage required by the set-aside provisions of a specific commodity program. ~ 1 Eutrophication The process by which a body of water becomes rich in nutrients. This can happen naturally or by human activity, usually in the form of industrial or municipal wastewater or agricultural runoff. Farmers Home Administration {FmHA' The USDA agency that makes loans to farmers and homeowners. The FmHA is generally the farmer's lender of last resort. Federal crop insurance A federally subsidized crop insurance program available to farmers to protect them against unavoidable crop Tosses caused by drought, fire, hail, floods, and other natural disasters. Feed grains Grains such as corn, barley, oats, and sorghum that are com- monly fed to animals. Many feed grains are also consumed by people. Fixed costs Costs of production that generally do not change as a result of the volume or type of crop produced. Fixed costs include insurance, rent or land mortgage payments, interest, and machinery depreciation. Gene transfer The process of moving a gene from one organism to an- other. Current biotechnology methods permit the identification, isola- tion, and transfer of individual genes as a molecule of DNA. These methods make it possible to transfer genes between organisms that wouIcl not normally be able to exchange them. Government farm program outlays Total costs associated with federal commodity price and income support, storage, disaster, and related programs. In the case of storage payments, outlays involve payments to producers and =~rain handlers. Green manure The use of leguminous crops as a source of nitrogen when they are plowed into a field. r - -of

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422 GLOSSARY Highly erodible land Land that has an erodibility index of greater than S. This index is based on a field's inherent tendency to erode from rain or wind in the absence of cover crop. The erodibility index is based on the Universal Soil Loss Equation (USLE) and the Wind Erosion Equation (WEE), along with a soil's T-value, which is a measure of the amount of erosion in tons per year that a soil can tolerate without losing pro- ductiv*y. For most cropland soils, T values fall in the range of 3 to 5 tons per acre. Horizontal resistance A plant's ability to uniformly resist ah strains of a pathogen. Many different physiological and morphological traits that act independently or jointly to block the virulence of a pest determine such resistance. These traits are nonspecific and polygenic, in contrast to vertical or specific gene resistances that may be overcome by a mu- tated strain of the pathogen. Inputs Items purchased to carry out a farm's operation. Such items in- clude fertilizers, pesticides, seed, fuel, and animal feeds and drugs. Integrated pest management {IPM} A pest control strategy based on the determination of an economic threshold that indicates when a pest population is approaching the level at which control measures are necessary to prevent a decline in net returns. In principle, IPM is an ecologically based strategy that relies on natural mortality factors, such as natural enemies, weather, and crop management, and seeks control tactics that disrupt these factors as little as possible. Intercropping The planting of one crop into another crop, either between the rows or into the stubble of a previous crop. Living mulch An understory of vegetation that helps reduce soil erosion and adds organic matter to the soil, but which does not compete heav- ily with the crop for water and nutrients. Loan rate The commodity-specific doHar amount per unit of production (bushel or pound) that the CCC uses in making nonrecourse loans to producers. The loan rate is also known as the price support level. A major change in the Food Security Act of 1985 was to adjust the loan rates for each commodity between 75 and 85 percent of the average prices received by farmers for the previous 5 years, excluding the high and the low years. When the market price fans below the loan rate, producers who have taken out nonrecourse loans may turn over their crop to the CCC as repayment of the loan. The government accumu- lates stocks of commodities in this way. Low intensity animal production Systems of animal rearing for food products that strive to use less capital, energy, and fewer purchased inputs than conventional confinement systems. An example of a Tow intensity system is a pasture and hutch swine production system. Marketing order A voluntary agreement among a majority of the produc-

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GLOSSARY 423 ers of a commodity that must be approved by the USDA and follow certain guidelines. It generally applies to fruit and vegetable producers and is primarily designed to control supply and price by setting acreage limits, marketing quotas, and grading standards. Method A systematic way to accomplish a specific farming objective by integrating a number of practices. Examples include weed control, till- age, or soil fertility methods that generally entail the integration of a number of practices such as rotary hoeing, cultivation, manure spread- ing, and crop rotations. Multiline Crop seed composed of a mixture of several breeding lines of the same variety, each containing a different resistance gene to a spe- cific pest. A single breeding line is vulnerable to crop failure when a pathogen mutates and regains virulence over the single resistance gene. In contrast, the mixing of different resistance traits in a multiline greatly reduces the probability of crop damage. Net farm income The sum of all income minus expenses from the farm operation, which includes maintenance and depreciation of all build- ings, machinery, and dwellings located on the farm. To derive this figure, gross income (income before expenses) is adjusted to account for net quantity changes in inventory and year-to-year carryover. Nitrogen fixation The chemical transformation of atmospheric nitrogen (N2) into forms available to plants for growth. Certain species of sym- biotic and free-living bacteria can accomplish nitrogen fixation. The more efficient forms are symbiotic with plants, where a food supply and a protected environment are provider} to the bacteria within root nodules. The bacteria in turn supply fixed nitrogen to the plant. Strains of the genus Rhizobium are the symbiotic, nitrogen-fixing bacteria that associate with leguminous crops such as beans, clover, and alfalfa. Seeds of leguminous crops are often inoculated with a slurry of Rhizo- bium spores to promote nitrogen fixation by the crop. Nonpoint water pollution Pollution of water that does not enter water- ways from a specific "point" source, such as a pipe. Nonpoint pollut- ants are often carried from dispersed, diverse sources into water chan- nels by rain-induced runoff. Runoff from streets, open pit and strip mines, and agricultural fields are prominent examples. Nonrecourse loan Participants in federal commodity programs may ob- tain loans from the CCC by pledging planted or stored crops as colIat- eral. These loans enable producers to pay for planting costs or to store crops for later sale. The producer can settle the loan by paying it back with interest or by turning the stored crop over to the CCC when the loan period ends. Loans are generally paid off when market prices rise above loan rates. Crops are frequently forfeited to the CCC at the end of the loan period when market prices are below loan rates. Organic matter Living biota present in the soil or the decaying or decayed

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424 GLOSSARY remains of animals or plants. The living organic matter in the soil decomposes the dead organic matter. Organic matter in soil increases moisture and soluble nutrient retention, cation exchange, and water infiltration and can reduce soil erosion. Output A marketable product of a farming operation, such as cash crops, livestock products, or breeding stock. Pesticides Chemicals used by farmers to control pests such as weeds (her- bicides), insects (insecticides), plant diseases (fungicides), nematodes (nematicides); to regulate plant growth; or to simplify harvest (dessi- cants). Polyculture The growing of many crops at once in the same field. Practice A way of carrying out a discrete farming task such as a tillage operation, particular pesticide application technology, or single conser- vation practice. Most important farming operations preparing a seed- bed, controlling weeds and erosion, or maintaining fertilityrequire a combination of practices, or a method. Most farming operations can be carried out by different methods, each of which is a unique combina- tion of different practices. Recharge The replenishment of an aquifer with water from the land's surface. Ridge tillage A type of soil-conserving tillage where the soil is formed into ridges, and seeds are planted on the tops of the ridges. The soil and crop residues between the rows remain largely undisturbed during planting. Rotary hoe A tool pulled behind a tractor, designed to control weeds by dislodging weed seedlings at a very early stage of growth from the soil. Row crops Crops that require planting each year and are grown in rows, such as corn, soybeans, and sorghum. Scouting The inspection of a field for pests (insects, weeds, or pathogens). Scouting is a basic component of IPM systems. It is used to determine whether pest populations have reached levels that warrant intervention for control and to help determine the appropriate method of control. Set aside The percentage of a commodity program acreage base that must be idled in a given year. The purpose is to help reduce commodity supplies and limit the cost of farm programs. This idled land must meet federal requirements for weed and erosion control. If these re- quirements are not met, the farmer loses eligibility for program pay- ments and loans. Small grains Crops with small kernels, such as wheat, barley, oats, rice, and rye. Soil depth profile A vertical profile of distinct zones within a soil, called soil horizons. The top, or A horizon, is the zone of leaching (eluviation) and is most abundant in biomass composed of roots, bacteria, fungi,

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GLOSSARY 425 worms, and microscopic animals. The second, or B horizon, is the zone of accumulation (illuviation); it contains little living matter and is often richer in clays, iron, and aluminum oxides that have percolated down and accumulated from the A horizon. The C horizon is composer! of the weathered rock and true parent material of the soil. Specialty {high-value, crops Crops with a limited number of producers and demand or those with high per acre production costs and value. Examples include most fruit and vegetable crops, ornamentals, green- house crops, spices, and low volume crops, such as artichokes. Split application Breaking up the application of fertilizer into two or more applications throughout the growing season. Split applications are in- tended to supply nutrients more evenly and at times when the crop can most effectively use them. Storage payments Annual payments per bushed or by weight made to individuals and corporations for the storage of commodities in the Farmer Held Reserve or placed under loan to the CCC. Strip cropping A method of contour planting in conjunction with rota- tions that results in alternating strips of crops across the slopes of fields. When practiced with conservation tilIage, strip cropping is an important and highly effective erosion control method. System The overall approach used in crop or livestock production, often derives! from a farmer's goals, values, knowledge, available technolo- gies, and economic opportunities. A farming system influences the choice of methods and practices used to produce a crop or care for animals. Farming systems entail a combination of methods to accom- plish farming operations. Conventional and alternative systems may use common practices or methods, but they usually differ in overall philosophy. Systemic pesticide A pesticide that is absorbed within a plant system and distributed throughout the plant and fruit. Systems research Interdisciplinary research that integrates knowledge from several fields of study into research projects designed to generate knowledge and understanding of farming systems. Target price A commodity-specific price per unit of production (bushel or pound) for certain program commodities that is set by the Congress and administered by the USDA. Target prices are usually above market prices. They are used to determine deficiency payments. Understory Vegetation growing in the shade of taller plants. Universal Soil Loss Equation A = RKLSCP, where A is the computed soil loss per unit area over a specified time; it is usually expressed as tons/ acre/year. The factors R. K, and S reflect characteristics of climate and land that generally cannot be modified by human activity designed to influence erosion rates: amount and intensity of rainfall (R), soil erodi- bility (K), and steepness of field slope (S). The factor representing

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426 GLOSSARY length of slope (L) can be reduced by installing terraces, which effec- tively break the naturally occurring slope length into smaller segments. (The effective slope length can also be shortened by strip cropping and grassy waterways, but this is reflected in the P factor.) The remaining two factors reflect the effects of human activities on erosion rates: soil cover and management practices (C) and supporting conservation prac- tices (P). Use it or lose it A characterization of water use by individuals or groups holding water rights contracts in western states. If the party with water rights uses less than its maximum allotment of water, subsequent rights to the unused portion of the fun allotment can, under certain circum- stances, be transferred to another party. Variable costs The portion of total cash production costs used for inputs needed to produce a specific yield of a specific crop. Variable costs typically include fertilizers, seed, pesticides, hired labor, fuel, repairs, and animal feed and drugs. Vine dressing The trimming of vines to maximize production. Water depletion allowance A provision of the tax law that allows for a tax deduction based on the depletion of certain aquifers used for agri- cultural irrigation. Water-holding capacity The ability of a soil and crop system to hold water in the root zone.