The cultivated area decreased to 20.1% of the total (19.9% of arable land and 0.2% of tree crops), while it was 24.7% at the end of the 1950s. The area devoted to meadows and pastures also decreased (from 37% to 25.8%) and the extension of the forest cover also slightly decreased (from 33.1% to 31.0%). Consequently, only uncultivated and unproductive increased (from 5.8% to 23.1%), in relation to a progressive abandonment by American farmers of marginal lands less susceptible to intensive exploitation through the use of cars. The fleet of machines available for agricultural activities has grown in an exceptional way: there are as many as 4,380,000 tractors and 645,000 harvesters-threshing machines.
The reorganization of the agricultural enterprise on an increasingly efficient competitive basis has led to the number of farms (farms) from 6,350,000 in 1940 to 2,850,000 in 1972, while the average area of the farms has more than doubled, exceeding 150 hectares. The number of tenants (350,000) has contracted particularly, so that today they represent only 10% of the peasants of the USA. The increase in specialization has meant that 60% of farms now derive more than half of their income from farming alone or from the practice of a single crop (especially when it comes to cereals, tobacco, cotton or fruit trees). The share of farms with a turnover of more than $ 20,000 doubled in 1970 compared to ten years earlier (20% against 9%) and the share of the market pertaining to these large companies has become by far the most prevalent (74% of the entire turnover of the agricultural sector; 51% ten years earlier). The massive capitalist surge of agricultural enterprises has resulted in a great increase in labor productivity over the course of twenty years: a farmer who produced food for fifteen people is now producing nearly fifty of them; of the 10 million farmers in 1950, in fact, less than a third remained in the farms and even less is the share of those left to cultivate the fields.
The irrigated area has now reached 8.5 million ha, with peaks in the Pacific strip, where the systematic enhancement of the large water reserves formed by the rivers on the western slope of the Rocky Mountains has continued.
Among crops, cereals continue to dominate, even if their incidence on the total of arable land has fallen below 40%. Corn prevails above all, grown mainly in the Central States (Jowa, Illinois, Indiana, Minnesota, Nebraska). For wheat, the states of Kansas and North-Dakota are worth mentioning, which alone supply over a third of the product. Almost half of the cotton comes from the southern states (Texas, New Mexico, Arizona, Nevada and California): Texas alone accounts for a third of production. Most of the tobacco (about 65%) is sourced from N. Carolina and Kentucky. In comparison with the past there is an increased specialization of the various territories with regard to the different crops, many of which show strong contractions of the surfaces concerned (cotton: −30% in 15 years; tobacco −50%), especially where yields are less competitive; after all, one of the characteristic features of US agriculture is the dizzying increase in productivity per hectare, which has generally made it possible to maintain or increase the overall levels of production (see table 3).
Horticulture has had a very notable development; in some fields the USA has acquired a solid position of supremacy in world production: thus, for example, for grapefruit (73%), oranges and mandarins (26%), lemons (20%) and peaches (33 %) (see table 4).
The forest cover covers over 296 million hectares, about two thirds of which are considered accessible for commercial exploitation. Over 25% of the forests are administered by the federal government or local administrations, while the rest of the forest area belongs to private individuals (about half of this share falls within the boundaries of the farms). Every year the fire attacks over 1 million hectares of forest, which requires a strong commitment and a complex organization of the fire-fighting services; almost 500,000 hectares of wood are currently covered by a capillary protection against fires. The average area reforested in the years 1970-71 was around 650,000 hectares.
The systematic enhancement of the forest mantle allows a production of wood on average higher than 300 million m 3 (especially coniferous wood, among which Douglas fir stands out with over 20% of the total).
The zootechnical patrimony has been strengthened through a very marked rationalization of the breeding practices, with the use of particular cross breeds and with the adoption of selected feeds; in this field too, specialization has become the norm. The most enhanced sector was that of beef cattle, which rose from 96 to 122.8 million head between 1960 and 1977. On the other hand, the number of pigs contracted (from 59 to 54.9 million head). dairy cows (from 19.5 to 12 million heads) and sheep (from 33 to 12.8 million); horses and mules, which before the last conflict were over 14 million, are now less than 10 million. Both for milk and meat, the yields per head increased significantly (see table 5).
Fishing activity has for some time stabilized at good production levels (3,101,544 tonnes of catch in 1977, slightly higher than 10 years ago), but the USA have lost various positions in the world ranking due to the enormous development. which has affected this sector in other countries (such as Peru, the Soviet Union and Norway).
