structural:scholar_edition, stylistic:tone
Modern mechanized techniques

Modern mechanized hay production today is usually performed by a number of machines. While small operations use a tractor to pull various implements for mowing and raking, larger operations use specialized machines such as a mower or a swather, which are designed to cut the hay and arrange it into a windrow in one step. Balers are usually pulled by a tractor, with larger balers requiring more powerful tractors.

Mobile balers, machines that gather and bale hay in one process were first developed around 1940. The initial balers produced rectangular bales that were small enough for an individual to lift, typically weighing between 70 and 100 pounds (32 to 45 kg) each. The size and shape of these bales allowed for manual handling, including lifting, stacking on transport vehicles, and constructing a haystack by hand. To reduce labor and enhance safety, loaders and stackers were subsequently developed to mechanize the transportation of small bales from the field to the haystack or hay barn. Later in the 20th century, balers were developed capable of producing large bales that weigh up to 3,000 pounds (1,400 kg).

Conditioning of hay crop during cutting or soon thereafter is popular. The basic idea is that it decreases drying time, particularly in humid climates or if rain threatens to interfere with haying. Usually, rollers or flails inside a mower conditioner crimp, crack or strip the alfalfa or grass stems to increase evaporation rate. Sometimes, a salt solution is sprayed over the top of the hay (generally alfalfa) that helps to dry the hay.