a tract of land on which farm animals graze. A distinction is made between natural and manmade pastures. The vegetation of natural pastures consists of wild perennial herbs, lichens (tundra), subshrubs, and shrubs (tundra, semidesert, and desert). Manmade pastures are created by planting a mixture of perennial and annual legumes and grasses (seeCULTIVATED PASTURES).

Pastures are one of the principal sources of the most inexpensive yet nutritious green feed for livestock. Almost three-fourths of the green feed needed for agricultural animals in the USSR is provided by pastures. The productivity of agricultural animals kept in pastures is 25 to 40 percent higher than those fed by other means. The quality of products is significantly better, and their prime cost is 20 to 30 percent lower. Animals are put out to pasture when the plants are in the early stages of vegetation and contain the greatest amount of nutrients.

The livestock are pastured for 125 to 150 days in the forest zone, about 170 days in the forest-steppe zone, about 200 days in the steppe zone, about 250 days in the semidesert zone, and nearly year-round in the tundra and desert zones. In mountain regions, subalpine and alpine pastures are used for summer transhumant pasturing (for two or three months). In 1972, natural pastures in the USSR (for all types of farms) occupied 329 million hectares, (ha). In addition, reindeer pastures occupied 343 million ha. Pastures make up the majority of agricultural lands in Turkmenistan (more than 96 percent), Uzbekistan (84 percent), Kirghizia (83 percent), Kazakhstan (80 percent), and Tadzhikistan (more than 77 percent). Pastures occupy 10 to 15 percent of all agricultural land in the Ukraine, Latvia, Lithuania, Byelorussia, Moldavia, and the central regions of the RSFSR.

Several natural zones with characteristic types of pastures are identified in the USSR. In the tundra and forest-tundra zones, swamps, thickets, and other such areas are used for pastures. The yield of edible material ranges from 0.1 to 4 quintals per ha., depending on the type of pasture. In the forest zone, livestock are pastured in dry valleys, in swamps, and on floodplains. Cattle graze well on all types of pastures, whereas sheep prefer dry valleys. The yield of edible material ranges from 7 to 45 quintals per ha.

In the forest-steppe zone, pastures are confined primarily to the southern and eastern slopes and the bottoms of ravines and gulleys. The yield of edible material ranges from 12 to 16 quintals per ha in the Asian part and from 20 to 25 quintals per ha in the European part. The vegetation in the Asian part consists of mixed herbs and reed bent or reed bent and sheep fescue. Pastures in the European part consist of grasses, legumes, and mixed herbs.

As one moves from north to south in the steppe zone of the European part of the USSR, the mesophyllic grass and legume vegetation is replaced by feather grass and feather grass-sheep fescue. The yield of edible material ranges from 20 to 25 quintals per ha. Along with feather grass and sheep fescue, pastures in the Asian steppes contain wormwood, sedge, and other plants (the yield of edible material is 10–18 quintals per ha). There are good spring and autumn pastures for fattening cattle. In the southern part of the steppe, near where the terrain changes to semidesert, there are salt marshes that are used as pastures in dry years (yield of edible material is 20 to 40 quintals per ha).

The semidesert zone has wormwood-grass, sheep fescue-pyre-thrum, and wormwood-thistle pastures. The first two types are used primarily for grazing sheep, and the third is used for the autumn and winter grazing of sheep and camels. The yield of edible material is 8 to 10 quintals per ha.

In the desert zone there are several types of pasture for sheep and camels: ephemeral, wormwood-ephemeral, succulent-thistle, wormwood, wormwood-thistle, wormwood-cereal, and herb-scrub. The yield of edible material is 2 to 10 quintals per ha.

Mountain pastures in different regions of the USSR have their own characteristic features, but a vertical zonality in terms of composition is common to them all. Thus, the pastures of mountain regions are divided into semidesert (occupying the foothills and lowest parts of the mountains), mountain-steppe, meadow-steppe, mountain-forest, subalpine, and alpine types. The best among these are the mountain-forest and subalpine pastures. Mountain-forest pastures are used in the summer to graze dairy cattle; their yield of edible material is 30 to 45 quintals per ha.

Subalpine meadows are good summer pastures for cattle; they also produce good quality hay. The yield of edible green mass reaches 50 quintals per ha.

Agricultural animals are put out to graze in mountain pastures in the spring. They graze in semidesert and mountain-steppe pastures, and later the herds are driven to the forest-steppe and forested belts of the mountains and to the subalpine belt. Cattle stay at this elevation until the end of the season, but sheep and goats are driven directly to the alpine pastures.

The average productivity of natural pastures in the USSR as a whole is 13 quintals of edible materials per ha. The least productive pastures are the desert pastures of Turkmenistan, Uzbekistan, and Kazakhstan. The productivity of natural pastures may be increased through proper utilization and the application of meliorative measures. Pasture maintenance involves alternating livestock grazing, mowing, and implementing measures to control herbage. The pasture rotation system includes enclosed grazing, top-dressing with fertilizers, mowing uneaten plants, controlling weeds and noxious plants, leaving herbage with valuable fodder plants until the seeds are dropped (natural seeding), planting leguminous and cereal seeds to increase the number of such plants in the pasture, and retaining or diverting meltwater.

In foreign countries, natural feed lands are not divided into pastures and hayfields as is done in the USSR. Such lands are considered “nonarable” and, depending on the needs of the farms, are used for grazing, for hay, or for both. Such pastures make up the highest proportion of all agricultural land in Australia, New Zealand, Great Britain, the United States, and Spain (see Table 1).