July 18, 2013

Putting up dry, high quality hay from summer annual grasses can be challenging.  Moist hay can lead to moldy, "hot" hay and increased deterioration.  This old rhyme captures the steps to success:  Cut it early, cut it high. Crimp the stems, and they will dry.

Summer annual grasses include sorghum-sudan hybrids, pearl millet, and forage sorghums, also know as cane hay. Most  harvest and storage problems start with handling the stems, which are low in protein and energy and unbearably slow to dry.  (Lower stems may even contain toxic nitrates.)  To solve the stem problem, cut early when plants are only waist high and contain more protein and energy than later. At this stage stems are smaller and will dry more easily.

Cutting these grasses high, leaving about eight inches of stubble, offers three benefits:

• it helps plants start regrowth quicker;
• it holds hay off the ground so air can help dry underneath; and
• it keeps many nitrates out in the field stubble rather then harvesting them in the hay.

The third thing to remember when harvesting a summer annual grass is to always crimp it. Even when stems are small, the waxy coating on the stems causes slow drying.  With crimping, the stems are broken open, allowing water to evaporate more quickly.

Bruce Anderson
Extension Forage Specialist