| 110 | Soil |
| 120 | Land |
| 199 | Soil and land, general |
| 210 | Water resources |
| 310 | River basins |
| 320 | Watersheds |
| 330 | Wetland and riparian systems |
| 399 | Watersheds and river basins, general |
| 410 | Air |
| 420 | Weather |
| 430 | Climate |
| 440 | Solar radiation |
| 499 | Atmosphere, general/other |
| 510 | Wilderness |
| 520 | Campgrounds and picnic areas |
| 530 | Parks and urban green space |
| 599 | Recreational resources, general/other |
| 610 | Conifer forests of the North |
| 611 | Conifer forests of the South |
| 612 | Conifer forests of the West |
| 613 | Mixed conifer-broadleaf forests |
| 620 | Broadleaf forests of the North |
| 621 | Broadleaf forests of the South |
| 622 | Broadleaf forests of the West |
| 630 | Chaparral and shrub lands |
| 640 | Tropical forests |
| 650 | Wood and wood products |
| 660 | Paper and pulp derived products |
| 670 | Short rotation woody crops, including holiday trees |
| 680 | Other products of the forest |
| 699 | Trees, forests, and forest products, general |
| 710 | Desert and semidesert shrub land and shinnery |
| 720 | Pinyon-juniper |
| 730 | Mountain grasslands, meadow, and alpine |
| 780 | Grasslands, other |
| 790 | Rangelands, other |
| 799 | Rangelands and grasslands, general |
| 810 | Finfish |
| 811 | Shellfish |
| 812 | Fish habitats |
| 819 | Natural fisheries, other |
| 820 | Wild birds |
| 830 | Wild animals |
| 840 | Fur-bearing animals |
| 850 | Wildlife habitats |
| 860 | Endangered species |
| 899 | Wildlife and natural fisheries, general/other |
| 910 | Grapefruit |
| 920 | Orange |
| 930 | Lemon |
| 999 | Citrus, general/other |
| 1010 | Banana |
| 1020 | Pineapple |
| 1030 | Papaya |
| 1040 | Mango |
| 1050 | Date |
| 1060 | Kiwi |
| 1099 | Tropical/subtropical fruit, general/other |
| 1110 | Apple |
| 1111 | Apricot |
| 1112 | Cherry |
| 1113 | Nectarine |
| 1114 | Peach |
| 1115 | Pear |
| 1116 | Plum |
| 1119 | Deciduous tree fruits, other |
| 1120 | Blueberry |
| 1121 | Cranberry |
| 1122 | Strawberry |
| 1123 | Raspberry |
| 1129 | Berries and cane fruits, other |
| 1130 | Table grapes |
| 1131 | Wine grapes |
| 1132 | Raisin grapes |
| 1139 | Grapes, other |
| 1199 | Deciduous and small fruits, general/other |
| 1210 | Filbert |
| 1211 | Pecan |
| 1212 | Almond |
| 1213 | Walnut |
| 1219 | Edible tree nuts, general/other |
| 1310 | Potato |
| 1410 | Beans (dry) |
| 1411 | Beans (fresh, fresh-processed) |
| 1412 | Peas (dry) |
| 1413 | Peas (fresh, fresh-processed) |
| 1414 | Lentil |
| 1419 | Leguminous vegetables, other |
| 1420 | Melons (includes cantaloupe, muskmelon, watermelon) |
| 1421 | Cucumber |
| 1429 | Cucurbits, other (includes pumpkin, squash, gourd) |
| 1430 | Greens and leafy vegetables (includes endive, lettuce, spinach, turnip-greens, celery, rhubarb, parsley, asparagus) |
| 1440 | Cole crops (includes cabbage, kale, broccoli, brussels sprouts, cauliflower, kohlrabi) |
| 1450 | Sweet potato |
| 1451 | Onion, garlic, leek, shallot |
| 1452 | Carrot |
| 1453 | Yam |
| 1454 | Taro |
| 1455 | Cassava (or manioc) |
| 1459 | Rhizomes, tubers, bulbs, and root crops, general/other (for potato use 1310) |
| 1460 | Tomato |
| 1461 | Peppers |
| 1462 | Eggplant |
| 1469 | Solanaceous and related crops, general/other (for potato use 1310) |
| 1470 | Mushrooms and other edible fungi |
| 1480 | Sweetcorn |
| 1499 | Vegetables, general/other |
| 1510 | Corn (for sweetcorn use 1480) |
| 1511 | Popcorn |
| 1520 | Grain sorghum |
| 1530 | Rice |
| 1540 | Hard red winter wheat |
| 1541 | Hard red spring wheat |
| 1542 | Soft red wheat |
| 1543 | Soft white wheat (includes club, western) |
| 1544 | Hard white wheat |
| 1545 | Durum wheat |
| 1549 | Wheat, other |
| 1550 | Barley |
| 1560 | Oats |
| 1570 | Rye |
| 1599 | Grain crops, general/other (includes buckwheat, millet, triticale) |
| 1610 | Pasture |
| 1620 | Warm season perennial grasses (includes dallisgrass, bluestems, bermudagrass) |
| 1621 | Cool season perennial grasses (includes bluegrass, bromegrass, fescue, orchardgrass, perennial ryegrass, timothy, wheatgrass) |
| 1629 | Perennial grasses, other |
| 1630 | Summer annual grasses (includes forage sorghums, sudangrass, sorghum-sudangrass hybrids) |
| 1631 | Winter annual grasses (includes annual ryegrass) |
| 1639 | Annual grasses, other |
| 1640 | Alfalfa |
| 1641 | Trefoil |
| 1642 | Red clover |
| 1643 | Crownvetch |
| 1644 | Winter annual legumes (includes subterranean clover, arrowleaf clover) |
| 1649 | Forage legumes, other |
| 1699 | Pasture and forage crops, general/other |
| 1710 | Upland cotton |
| 1711 | Long fiber cotton |
| 1719 | Cotton, other |
| 1720 | Kenaf |
| 1730 | Hemp |
| 1740 | Ramie |
| 1750 | Agave |
| 1799 | Fiber crops, general/other |
| 1810 | Cottonseed (for meal, oil, etc.) |
| 1820 | Soybean |
| 1830 | Peanut |
| 1840 | Castor |
| 1841 | Crambe |
| 1842 | Flax |
| 1843 | Safflower |
| 1844 | Sunflower |
| 1845 | Jojoba |
| 1846 | Coconut |
| 1847 | Palm |
| 1848 | Canola |
| 1849 | Cuphea |
| 1850 | Lesquerella |
| 1851 | Meadowfoam |
| 1852 | Rape |
| 1853 | Sesame |
| 1854 | Chinese tallow |
| 1855 | Tung |
| 1899 | Oilseed and oil crops, general/other |
| 1910 | Flue-cured tobacco |
| 1920 | Burley tobacco |
| 1930 | Cigar-type tobacco |
| 1999 | Tobacco, general/other |
| 2010 | Sugar beet |
| 2020 | Sugar cane |
| 2030 | Sweet sorghum |
| 2099 | Sugar crops, general/other |
| 2110 | Ornamental trees and shrubs |
| 2120 | Herbaceous perennials and decorative greens |
| 2121 | Cut flowers, foliage, and greens |
| 2122 | Potted plants |
| 2123 | Bedding/garden plants |
| 2129 | Florist crops, other |
| 2130 | Turf (includes bentgrass, bermudagrass, bluegrass, dichondra, fescue, ryegrass, zoysia) |
| 2140 | Ground covers |
| 2150 | Aquatic plants |
| 2160 | Arboreta and botanical gardens |
| 2199 | Ornamentals and turf, general/other (includes cacti) |
| 2210 | Chemurgic crops |
| 2220 | Medicinal crops, non-narcotic |
| 2221 | Narcotic plants |
| 2230 | Hops |
| 2231 | Mint |
| 2232 | Coffee |
| 2233 | Cocoa |
| 2234 | Tea |
| 2235 | Herbs and spices |
| 2239 | Flavoring and beverage plants, other |
| 2240 | Guayule |
| 2241 | Hevea |
| 2242 | Gums |
| 2249 | Rubber, gum, and resin plants, other |
| 2299 | Miscellaneous and new crops, general/other |
| 2410 | Cross-commodity research--multiple crops |
| 2420 | Noncrop plant research |
| 2499 | Plant research, general |
| 3010 | Honey bees |
| 3020 | Honey and honey products |
| 3030 | Non-honey apiary products |
| 3090 | Other Pollinators |
| 3099 | Bees, honey, and other pollinators, general |
| 3110 | Insects |
| 3120 | Spiders, mites, ticks, and other arthropods |
| 3130 | Nematodes |
| 3199 | Invertebrates, general/other |
| 3210 | Egg-type chicken, live animal |
| 3220 | Meat-type chicken, live animal |
| 3230 | Turkey, live animal |
| 3240 | Duck and goose, live animal |
| 3250 | Ratites (e.g., ostrich, emu, rhea), live animal |
| 3260 | Poultry meat |
| 3270 | Eggs |
| 3280 | Other poultry products |
| 3299 | Poultry, general/other |
| 3310 | Beef cattle, live animal |
| 3320 | Meat, beef cattle |
| 3330 | Other beef cattle products |
| 3399 | Beef cattle, general/other |
| 3410 | Dairy cattle, live animal |
| 3420 | Butter |
| 3430 | Cheese |
| 3440 | Meat, dairy cattle |
| 3450 | Milk |
| 3460 | Ice cream |
| 3470 | Other dairy cattle products |
| 3499 | Dairy cattle, general/other |
| 3510 | Swine, live animal |
| 3520 | Meat, swine |
| 3530 | Other swine products |
| 3599 | Swine, general/other |
| 3610 | Sheep, live animal |
| 3620 | Meat, sheep |
| 3630 | Wool fiber |
| 3699 | Sheep and wool, general/other |
| 3710 | Catfish |
| 3711 | Trout |
| 3712 | Salmon |
| 3713 | Striped bass |
| 3714 | Tilapia |
| 3715 | Baitfish (minnows and shiners) |
| 3716 | Ornamental finfish |
| 3719 | Other cultured finfish |
| 3720 | Crawfish |
| 3721 | Marine shrimp |
| 3722 | Freshwater shrimp |
| 3723 | Oysters |
| 3724 | Clams and mussels |
| 3725 | Ornamental shellfish |
| 3729 | Other cultured shellfish |
| 3799 | Cultured aquatic animals, general/other |
| 3810 | Horses, ponies, and mules |
| 3820 | Goats, meat and mohair |
| 3830 | Pets (companion animals) |
| 3840 | Laboratory animals |
| 3899 | Other animals, general |
| 3910 | Cross-commodity research--multiple animal species |
| 3999 | Animal research, general |
| 4010 | Bacteria |
| 4020 | Fungi (includes yeast) |
| 4030 | Viruses |
| 4040 | Viroids, mycoplasmas, spiroplasmas, etc. |
| 4050 | Protozoa |
| 4099 | Microorganisms, general/other |
| 5010 | Food (not readily associated with specific plant and animal products) |
| 5110 | Clothing/apparel |
| 5120 | Textiles |
| 5199 | Clothing and textiles, general |
| 5210 | Fertilizers |
| 5220 | Pesticides (includes herbicides, insecticides, fungicides, etc.) |
| 5230 | Feed and feed additives |
| 5240 | Seeds and other plant propagules |
| 5299 | Agricultural supplies, general/other |
| 5310 | Machinery and equipment |
| 5320 | Houses (human residences), furniture, household equipment, non-textile furnishings |
| 5330 | Farm structures and related facilities |
| 5340 | Nonfarm structures and related facilities, including those used in marketing, storing, processing, and distributing functions, and for recreational uses |
| 5350 | Domestic and community water supply facilities and systems |
| 5360 | Drainage and irrigation facilities and systems |
| 5370 | Sewage and waste disposal facilities and systems |
| 5399 | Structures, facilities, and equipment, general/other |
| 6010 | Individuals (as workers, consumers, members of society) |
| 6020 | The family and its members |
| 6030 | The farm as an enterprise |
| 6040 | Real estate |
| 6050 | Communities, areas, and regions, including states and their institutions and organizations |
| 6099 | People and communities, general/other |
| 6110 | Economy of the United States and sectors thereof |
| 6120 | International economy and sectors thereof |
| 6199 | Economy, general/other |
| 6210 | Farmer cooperatives |
| 6220 | Marketing, processing, and supply firms other than cooperatives |
| 6230 | Marketing systems and sectors thereof |
| 6299 | Marketing, general/other |
| 7010 | Biological Cell Systems |
| 7110 | Research on research management (not research management per se) |
| 7210 | Remote sensing equipment and technology |
| 7220 | Sensory evaluation/analysis methods (human senses) |
| 7299 | Research equipment and methods, general/other |
| 7310 | Experimental design and statistical methods |
| 7410 | General technology |