Hay is the dried above-ground biomass of grassland plants such as grasses, herbs and legumes. It is usually used as fodder for livestock and domestic animals. The hay is to be distinguished from the straw. Straw is the name given to the dried, above-ground biomass of threshing plants (cereals, legumes and oil plants) after threshing, i.e. after their seeds have been removed (ears of corn, pods, oilseed).
In order to conserve the growth of grassland, for example, meadows consisting of grasses and usually also meadow herbs by drying, the mown development must be dried as quickly as possible, but at the same time gently, to a dry matter content of over 80% in the form of the Floor drying, scaffolding drying or under-roof drying with the use of ventilation methods.
In the case of soil drying, the growth remains on the grassland for several days after mowing for air drying. During this time, the mowing material is first tedded (spread apart) after cutting, raked together again overnight to reduce moisture penetration from dew to form so-called night swaths, and usually also turned one or more times during the day to then be swathed again for removal to become.
In modern agriculture, tedding, turning and raking are done mechanically using hay tedders and rakes. Still, in exceptional cases (e.g. for hobby farmers or on steep slopes), it is also done by hand with a hay fork and hay rake. Three to four days of favourable, dry weather are usually required for soil drying. Soil drying is associated with relatively high substance losses from the harvested crops due to the breaking off of flakes of the harvested crops, the so-called crumbling losses.
In modern agriculture, to remove the hay, it is usually pressed with baling presses into small bales weighing between 10 and 30 kg and sizes around 35 × 25 × 100 cm or into large round or square bales weighing up to several hundred kilograms. If stored dry, the hay can be used as feed for farm animals for over a year.
In order to reduce the weather risk, methods of haymaking have been developed on scaffolding instead of on the ground, especially in areas with a lot of precipitation, through which the negative influences of rain on drying and, at the same time, the crumbling losses could be reduced.
However, A disadvantage in rational agriculture by today’s standards is that all scaffold drying processes require a high degree of manual work. Various forms of hay riders are used for drying the scaffold, namely Heinzen(individual posts with crossbars), Schwedenreuter (strings or wires stretched to posts), hay huts (slatted frames set up opposite each other in the form of a tent) or Dreibockreuter (pyramid-shaped constructions made of three posts connected with crossbars).
In the case of the Heinzen and Schwedenreutern, the harvested crop can be hung on these immediately after the cut, while in the case of the Heuhütten or Dreibockreutern, pre-drying to around 50% dry matter content on the ground is required.