June 6, 2008

With this spring's cool wet weather optimal conditions for making hay have been rare. You've heard the maxim a hundred times, but do you know why it's best to make hay when the sun shines?

Getting hay to dry fast is important for several reasons, including the most obvious, to avoid rain damage.

Alfalfa plant cells don't die immediately after cutting. Instead, the cells continue to respire until hay gets down to about 50% moisture, converting valuable carbohydrates into carbon dioxide gas. Under the best conditions, about 5% of hay's potential weight will be lost as gas. When hay dries slowly though, as much as 15% can simply disappear as carbon dioxide.

Growers also want to get hay off the field quickly so new growth isn't delayed by cut hay lying on top of it or damaged by harvest machinery.

Speeding Hay Dry-down

There are a couple things growers can can do -- in addition to cutting when it's sunny, hot, dry, and breezy -- to help hay dry faster.

First, spread recently cut hay in as wide a swath as possible. The more hay is exposed to direct sunlight, the faster it dries. After the top dries, turn hay gently by adjusting angles, speed, or position on the rake to expose moister hay under the swath, then fluff the swath for better internal air movement.

Fast hay dry-down is a goal of all haymakers. Good timing and proper equipment operations can help you achieve this goal.

Bruce Anderson
Extension Forage Specialist