Glossary of Agronomic Terms (Martin et al. 1976)

A Horizon The surface and subsurface soil that contains most of the organic matter and is subject to leaching. Abscission The natural separation of leaves, flowers, and fruits from the stems or other plant parts by the formation of a special layer of thin-walled cells. Acid soil A soil with a pH reaction of less than 7 (usually less than 6.6). An acid soil has a preponderance of hydrogen ions over hydroxyl ions. Litmus paper turns red in contact with most acid soils. Adventitious Arising from an unusual position on a stem or at the crown of a grass plant. Aerial roots Roots that arise from the stem above the ground. Aftermath The second or shorter growth of meadow plants in the same season after a or has been cut. Agrobiology A phase of the study of agronomy dealing with the relation of yield to the quantity of an added fertilizer element. Agronomy The science of crop production and soil management. The name is derived from the Greek words agros (field) and nomos (to manage). Aleurone The outer layer of cells of the endosperm of the seed. Alkali soil A soil, usually above pH 8.5, containing alkali salts in quantities that usually are deleterious to crop production. Alkaline soil A soil with a pH above 7, usually above pH 7.3. Ammonification The formation of ammonia or ammonium compounds in soils. Amylose The straight-chain fraction of normal starch. 106 Glossary of Agronomic terms

Angiosperms The higher seed plants. Annual A plant that completes its life cycle from seed in one year. Anther The part of the stamen that contains the pollen. Anthesis The period during which the flower is open and, in grasses, the period when the anthers are extended from the glumes. Apomixis A type of asexual production of , as in Kentucky bluegrass. Aquatic plant A plant that lives in the water. Arid climate A dry climate with an annual precipitation usually less than 10 in. and not suitable for crop production without irrigation. Asexual Reproduction without involving the germ or sexual reproduction cells. Ash The nonvolatile residue resulting from the complete burning of organic matter. Auxins Organic substances that cause stem elongation. Awn The beard or bristle extending from the tip or back of the lemma of a grass flower. B Horizon The subsoil layer in which certain leached substances are deposited. Backcross The cross of a hybrid with one of the parental types. Beard The awn of grasses. Bed A narrow flat-topped ridge on which are grown with a furrow on each side for drainage of excess water. Biennial Of 2 years' duration; a plant germinating one season and producing seed the next.

Binder A machine for cutting a crop and tying it into bundles with twine. Blade The part of the leaf above the sheath. Boll The subspherical or ovoid fruit of or cotton. Boot The upper leaf sheath of a grass. Glossary of Agronomic terms 107

Branch A lateral stem. Broadcast To sow or scatter seed on the surface of the land by hand or by machinery. C Horizon The layer of weathered parent rock material below the B horizon of the soil but above the unweathered rock. Calcareous soil An alkaline soil containing sufficient calcium and magnesium carbonate to cause visible effervescence when treated with hydrochloric acid. Caliche A cemented deposit of calcium carbonate often mixed with magnesium carbonate at various depths, charac• teristic of many of the semiarid and arid soils of the world. Cambium The growing layer of the stem. Carbohydrates The main constituents of plants, including sugars, starches, and cellulose, in which the ratio of hydrogen molecules to oxygen molecules is 2: 1. Carotene A yellow pigment in green leaves and other plant parts, which is the forerunner of vitamin A. Caryopsis The grain or fruit of grasses. Cell The unit of structure in plants. A living cell contains protoplasm, which includes a nucleus and cytoplasm within the cell wall. A grass cultivated for its edible seeds or grains. Chernozem soil A dark to nearly black grassland soil high in organic matter developed in a subhumid climate. . Chestnut soil A soil having a dark brown surface developed under mixed tall and short grasses in a subhumid to semiarid climate. Chlorophyll The green coloring matter in plants that takes part in the process of photosynthesis. Chlorosis The yellowing of leaves and other chlorophyll-bearing plant parts. Clay Small mineral soil particles less than O.OO2mm in diameter. Climate The total long-time characteristic weather of any region. 108 Glossary of Agronomic terms

Coleoptile The sheath covering the first leaf of a grass seedling as it emerges from the soil. Combine A machine for harvesting and threshing in one operation.

Companion crop A crop grown with another crop, such as a small grain crop grown with a forage crop. Consumptive use The use of water in growing a crop, including water used in transpiration and evaporation. Cover crop A crop grown between orchard trees or on fields be• tween cropping seasons to protect the land from leaching and erosion. Crown The base of the stem where the roots arise. Culm The jointed stem of grasses. Cultivar (variety) A group of individuals within a species that differ from the rest of the species. Cytoplasm The contents of a cell outside of the nucleus. Deciduous Plants or trees that shed their leaves at a particular season or stage. Drill A machine for sowing seeds in furrows. Ecology The study of the mutual relations between organisms and their environment. Embryo The rudimentary plantlet within a seed. The germ. Endosperm The starchy interior of a grain or seed. Ensilage Silage. Epidermis The external layer of cells. Erosion The wearing away of the land surface by water or wind. Fallow Cropland left idle, usually for one growing season, while the soil is being cultivated to control weeds and conserve moisture. Fertilization (plant) The union of the male (pollen) nucleus with the female (egg) cell. Fertilization (soil) The application to the soil of elements or compounds that aid in the nutrition of plants. Glossary of Agronomic terms 109

Fibrous root A slender thread-like root, such as the roots in grasses. Fodder , sorghum, or other coarse grasses harvested whole and cured in an erect position.

Forage Vegetable matter, fresh or preserved, gathered and fed to animals. Gene The unit of inheritance, which is transmitted in the germ cells. Genetics The science of heredity, variation, and sex determination.

Gluten The protein in flour that enables the dough to rise. Grain (1) A caryopsis, (2) a collective term for the , (3) cereal seeds in bulk. Grass A plant of the family Gramineae.

Green manure Any crop or plant grown and plowed under to improve the soil, especially by the addition of organic matter. Hardpan A hardened or cemented soil horizon. Hay The herbage of grasses or fine-stemmed plants cut and cured for forage.

Humus The well-decomposed and stable part of the organic matter in the soil. Husk The coarse outer envelope of a fruit, such as the glumes of an ear of maize. Hybrid The offspring of two parents unlike in one or more heritable characters.

Inflorescence The flowering part of a plant. Leaf The lateral organ of a stem. Legume Any plant of the family Leguminoseae.

Lister An implement for furrowing land, often having a planting attachment. Loam A soil composed of a mixture of clay, silt, and less than 52% sand. 110 Glossary of Agronomic terms

Meadow An area covered with fine-stemmed forage plants, wholly or mainly perennial, and used to produce hay. Middlebuster A double-shovel plow or lister. Mulch A layer of plant residues on the surface of the soil. Neutral soil A soil neither acid nor alkaline, with a pH of about 7. Nutrient A chemical element taken into a plant that is essential for growth, development, and reproduction of the plant. Organic farming Growing crops without applying pesticides and mineral fertilizers in an inorganic form. Panicle An inflorescence with a main axis and subdivided branches, as in and sorghum. Pasture An area of land covered with grass or other herbaceous forage plants, used for grazing animals. Perennial Living more than 1 year but, in some cases, producing seed the first year. Plant Any organism belonging to the plant or vegetable kingdom. Planter A machine fOT opening the soil and dropping tubers, cuttings, seedlings, or seeds at intervals. Pollen The male germ cells produced in the anthers of a flower. Pollination The transfer of pollen from the anther to the stigma of a flower. Productivity The capability of a soil to produce a specified plant (of soil) or sequence of plants under a specified system of management. Profile (of soil) A vertical section of the soil through all its horizons and extending into the parental material. Protoplasm The contents of a living cell. Pubescent Covered with fine, soft, short, hairs. Pure line A strain of organisms that is genetically pure because of continued inbreeding. Rachis The axis of a spike in grasses. Radicle That part of the seed which upon growing becomes the root. Glossary of Agronomic terms 111

Reaction (of soil) The degree of acidity or alkalinity of the soil expressed as pH. Replication Multiple repetition of an experiment. Respiration The process of absorption of oxygen and giving out of carbon dioxide. Root The part of the plant (usually subterranean) which lacks nodes. Runner A creeping branch or stolon. Sand Small rock or mineral fragments having diameters ranging from 0.05 to 2 mm. Seed The ripened ovule enclosing a rudimentary plant and the food necessary for its germination. Seedling The juvenile stage of a plant grown from seed. Semiarid climate A climate which usually has an annual precipitation of between 25 and 50cm. Shoot A stem with its attached members. Silage Forage preserved in a succulent condition by partial fermentation in a tight container. Silt Small mineral soil particles of a diameter of 0.002 to 0.05mm. Single cross The first generation hybrid between two inbred lines. Soil The natural medium for the growth of land plants on the surface of the earth, composed of organic and mineral materials. Sow To place seeds in a position for growing. Spike An unbranched inflorescence in which the spikelets are sessile on the rachis, as in barley and wheat. Spikelet The unit of inflorescence in grasses, consisting of two outer glumes and one or more florets. Stamen The pollen-bearing organ of a flower. Stand The density of plant population per unit area. Sterile Incapable of sexual reproduction. Stigma The part of the pistil that receives the pollen. Stolon A modified creeping stem above ground that produces roots. 112 Glossary of Agronomic terms

Strain A group of plants derived from a variety. The dried remnants of fine-stemmed plants from which the seed has been removed. Stubble The basal portion of the stems of plants left standing after cutting. Subsoil The part of the soil below the plow depth or below the A horizon. Taproot A single central root. Tassel The staminate inflorescence of maize composed of panicled spikes. Tedder An implement for stirring hay in the swath or windrow. Terrace A channel or embankment across a slope approxi• mately on a contour to intercept runoff water. Till To plow or cultivate soil. Tiller An erect shoot arising from the crown of a grass plant. Tilth The physical condition of the soil with respect to its fitness for the planting or growth of a crop. Topsoil The surface soil, usually the plow depth of the A horizon. Transpiration The evaporation of moisture from plants through their leaves. Tuber A short thickened subterranean branch. Turf The upper stratum of soil filled with the roots and stems of low-growing grasses. Unisexual Containing either stamens or pistils, but not both. Unit character A hereditary trait that is transmitted by a single gene. Variation The occurrence of differences among individual plants of a species or variety. Variety (cultivar) A group of individuals within a species that differ from the rest of the species. Vein A bundle of threads of fibrovascular tissue in a plant leaf or other organ. Weed A plant that in its location is more harmful than beneficial. Glossary of Agronomic terms 113

Windrow Curing plant herbage that is dropped or raked into a row. Winter annual A plant that germinates in the fall of 1 year and matures in the spring or summer of the following year. References

Anderson MS, Keyes MG, Cromer GW (1942) Soluble material of soils in relation to their classification and general fertility. US Dep Agric Tech Bull 813, 54pp Arnon I (1972) Crop production in dry regions, vol 1. Hill Books, London, 650 pp Beatty MT, Peterson GW, Swindale LD (ed) (1979) Planning the uses and management of land. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America, Madison, Wisconsin, 1028 pp Black CA (1957) Soil-plant relationships. Wiley, New York, 332 pp Black CA, Van Riper GE, Burrows WC, Holland RF (ed) (1970) Agronomy in a changing world and research needs for the seventies. ASA Spec Pub119. American Society of Agronomy, Madison, Wisconsin, 65 pp Crowley JJ, (ed) (1986) Research for tomorrow; 1986 yearbook of . US Government Printing Office, Washington, DC, 336pp Day AD, Ludeke KL, (1987) Effects of soil materials, mulching treatments, and soil moisture on the growth and yield of western wheatgrass for coal mine reclamation. Desert Plants 8(3):136-139 Day AD, Ludeke KL (1988) Coal mine soil reclamation in the southwestern United States. Int Erosion Control Assoc Rep 20(1):13-15 Day AD, Ludeke KL (1990) Forest litter as a seed source in coal mine reclamation in the southwest. Desert Plants 10(2):58-60 Day AD, Thompson RK (1988) Effects of dried sewage sludge on wheat cultivars in the southwestern United States. J Arid Environ 14:93-99 Day AD, Tucker TC (1959) Production of small grains pasture forage using sewage effluent as a source of irrigation water and plant nutrients. Agron J 51:569-572 Day AD, Tucker TC (1960) Hay production of small grains utilizing city sewage effluent. Agron J 52:238-239 Day AD, Tucker TC, Vavich MG, (1962) Effects of city sewage effluent on the yield and quality of grain from barley, oats, and wheat. Agron J 54:133-135 Day AD, McFadyen JA, Tucker TC, Cluff CB (1981) Effects of municipal wastewater on the yield and quality of cotton. J Environ Qual 10(10):47-49 Day AD, Swingle RS, Tucker TC, Cluff CB (1982) Alfalfa hay grown with municipal wastewater and pump water. J Environ Qual 11(1):23-24 Day AD, Wilson JR, Katterman FR (1984) Bermudagrass grown with municipal waste• water. BioCycie 25(4):38-39 Day AD, Taylor BB, Pepper IL (1987a) Agricultural potential of municipal sewage. Agronomy Abstracts. American Society of Agronomy, Madison, 36pp Day AD, Taylor BB, Pepper IL, Minnich MM (1987b) Plant growth and seed cotton yield of upland cotton fertilized with liquid sewage sludge. Ariz Coop Ext Ser Agric Exp Stn Cotton Rep Ser P-69:19-21 Day AD, Thompson RK, Swingle RS (1987c) Effects of sewage sludge on yield and quality of wheat grain and straw in an arid environment. Desert Plants 8(3):104-105; 142-143 Day AD, Taylor BB, Pepper IL, Minnich MM (1988) Effects of sewage sludge on cotton lint quality. Ariz Coop Ext Ser Agric Exp Stn Cotton Rep Ser P-72:39-41 116 References

Day AD, Solomon MA, Ottman MJ, Taylor BB (1989) Crop response to sludge loading rates. BioCycle 30(8):72-75 Day AD, Ottman MJ, Taylor BB, Pepper IL,' Swingle RS (1990) Wheat responds to sewage sludge as fertilizer in an arid environment. J Arid Environ 18:239-244 Dean KC (1971) USBM finds many routes to stabilizing mining wastes. Mining Engin 23(12):61-63 Fuller WH (1975aj Soils of the desert southwest. University of Arizona Press, Tucson, 102pp Fuller WH (1975b) Management of southwestern desert soils. University of Arizona Press, Tucson, 195 pp Fuller WH (1983) Soil injection of sewage sludge. Univ Ariz Tech Bull 250, 20pp Fuller WH, Tucker TC (1977) Land utilization and disposal of organic wastes in arid regions. In: Elliott LF, Stevenson FJ (eds) Soils for management of organic wastes and waste waters. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America, Madison, Wisconsin, pp 473-489 Hambridge G (ed) (1938) Soils and men; 1938 yearbook of agriculture. US Government Printing Office, Washington, DC, 1232 pp Hambridge G (ed) (1941) Climate and man; 1941 yearbook of agriculture. US Govern• ment Printing Office, Washington, DC, 1248pp Hamilton H (ed) (1966) Our heritage of land and water resources; ASA Spec Publ 7. American Society of Agronomy, Madison, Wisconsin, 44 pp Haney RA Jr, Gonzales HJ, Paylor P (1985) College of agriculture; a century of dis• covery. University of Arizona, College of Agriculture, Tucson, 324pp Hayes J (ed) (1971) A good life for more people; 1971 yearbook of agriculture. US Government Printing Office, Washington, DC, 391 pp Hayes J (ed) (1972) Landscape for living; 1972 yearbook of agriculture. US Government Printing Office, Washington, DC, 376pp Hayes J (ed) (1977) Gardening for food and fun; 1977 yearbook of agriculture. US Government Printing Office, Washington, DC, 392 pp Hayes J (ed) (1978) Living on a few acres; 1978 yearbook of agriculture. US Government Printing Office, Washington, DC, 431 pp Hayes J (ed) (1983) Using our natural resources; 1983 yearbook of agriculture. US Government Printing Office, Washington, DC, 572 pp Hendricks DM (1985) Arizona soils. University of Arizona, College of Agriculture, Tucson, 244 pp Janick J, Schery RS, Woods FW, Ruttan VW (1969) Plant science: and introduction to world crops. Freeman, San Francisco, 740pp Katterman FRH, Day AD (1989) Plant growth factors in sewage sludge. BioCycle 30(3): 64-65 Kramer PJ (1949) Plant and soil water relationships. McGraw-Hill, New York, 347pp Martin JH, Leonard WH, Stamp DL (1976) Principles of field crop production. Macmillan, New York, 1118pp Miller CE, Turk LM (1943) Fundamentals of soil science. Wiley, New York, 462pp National Plant Food Institute (1962) Our land and its care. National Plant Food Institute, Washington, DC, 72pp Page AL, Gleason TL, Smith JE, Iskandar IK, Sommers LE (eds) (1983) Proceedings of the 1983 workshop on utilization of municipal wastewater and sludge on land. University of California, Riverside, 480 pp Pearson LC (1967) Principles of agronomy. Reinhold, New York, 434pp Schaller FW, Sutton P (eds) (1978) Reclamation of drastically disturbed lands. American Society of Agronomy, Crop Science Society of America and Soil Science Society of America, Madison, Wisconsin, 742 pp Sommers LE (1977) Chemical composition of sewages and analysis of their potential as fertilizers. J Environ Qual 6(2):225-232 Sopper WE, Kardos LT (eds) (1973) Recycling treated municipal wastewater and sludge through forest and cropland. Pennsylvania State University Press, University Park, Pennsylvania, 479 pp References 117

Sopper WE, Kerr SN (eds) (1979) Otilization of municipal sewage effluent and sludge on forest and disturbed land. Pennsylvania State University Press, University Park, Pennsylvania, 537 pp Sopper WE, Seaker EM, Bastian RK (1982) Land reclamation and biomas production with municipal wastewater and sludge. Pennsylvania State University Press, University Park, Pennsylvania, 524 pp Stefferud A (ed) (1955) Water; 1955 yearbook of agriculture. US Government Printing Office, Washington, DC, 751 pp Stefferud A (ed) (1957) Soil; 1957 yearbook of agriculture. US Government Printing Office, Washington, DC, 784pp Stefferud A (ed) (1958) Land; 1958 yearbook of agriculture. US Government Printing Office, Washington, DC, 605 pp Whyte W (ed) (1987) Our American land; 1987 yearbook of agriculture. US Government Printing Office, Washington, DC, 323 pp Woodward RW (1966) Response of some semi-dwarf spring to nitrogen and phosphorus fertilizer. Agron J 58:65-66