Hay Dessicants and Preservatives By Dan Undersander, Extension Forage Agronomist Much interest has been expressed in compounds to reduce field curing time of forages. This means that hay, as we all know, initial drying is rapid and loss of the final few percentages of moisture before harvesting takes considerable time. The desiccants that are effective contain potassium or sodium carbonate. This compound disturbs the waxy cuticle of the alfalfa stem to allow it to dry faster. Desiccants work only on legumes such as alfalfa, trefoil and clovers.
Effectiveness varies with climatic conditions.
Desiccants reduce drying time, most when drying conditions are good. Thus, they tend to work better on second and third cuttings in Wisconsin. They are recommended for hay making and are of less usefulness when forage is harvested as haylage. Preservatives are applied to the hay as it is harvested and prevents heating and spoilage of hay baled at high moisture contents. Preservatives are cost effective if used only when needed to prevent rain damage to hay, and if applied uniformly to windrow as it is entering the baler.