During haying season, one of the challenges producers face is reducing drying times, especially in regions experiencing more frequent rainfall events. Frequent rainfall events limit the opportunity to make hay without moisture damage. Fresh cut forage ranges from 70 to 80 per cent moisture which must be reduced to safely bale. The primary goal is to reduce the amount of time required to field cure hay to the desired moisture content of 14 to 18 per cent to prevent heating and moulding. Rain and humidity can extend drying times, thereby increasing dry matter losses due to respiration within the plant after cutting, microbial activity and oxidation of vitamins and minerals. Research has shown that four steps are required to increase field drying times.
Generally, hay should be cut between three to four inches above ground (two to four inches for alfalfa and three to four inches for grasses). At this height, the swath will be off the ground to allow for air to flow underneath enhancing the air circulation for drying.
Mechanical conditioning at the time of cutting has been shown to half the drying time under ideal conditions. Conditioning is the process of cracking or splitting the stem, which allows for moisture to be released. The idea is to try and dry the leaves and stems at the same rate. Types of conditioners include rollers and flail/impellers.
Research has shown that swath widths that cover a minimum of 60 per cent of the cut area will increase drying compared to narrower widths. Swath density is reduced as the swath windrows increases. Increased windrows expose the forage to more sun and air movement, which improves drying time. The narrower the windrows the denser it is and increases the chances for the swath to contact the ground reducing air flow and increases drying time. A drawback to wider windrows is that they must be raked or merged prior to baling.
If drying conditions are good, raking multiple swaths into a windrow will further improve the drying time. Moisture levels for alfalfa should be between 40 to 60 per cent and above 25 per cent for grasses to reduce leaf loss. Raking in the early morning, avoiding the heat of the day, may also help minimize leaf loss.
Hay moisture levels between 14 to 18 per cent are generally the target but bale type and size can factor into safe moisture levels for storage. Large round hard-core bales can be baled at 16 to 17 per cent moisture. Large round soft-core bales can be baled at 18 to 20 per cent moisture. Large square bales require moisture content between 12 to 14 per cent while small square bales can be baled at slightly higher moisture, around 18 per cent.
Properly cured hay is important for preserving forage quality at the time of cutting so pay attention to moisture levels. If hay is to be baled at a higher moisture level preservative can be applied at baling to prevent heating and spoilage/moulding by making moisture unavailable to microbes. Preservatives are recommended for use on hay with moisture levels below 35 per cent.
Information on hay management and hay preservatives can be found on the ministry website. If you have any questions about hay management or have other forage related questions, please contact your regional range management extension specialist or the Agriculture Knowledge Centre in Moose Jaw at 1-866-457-2377.