Demonstration of Rice "Strawlage" Production, 2013


Project Leader

Glenn Nader,
farm advisor, UC Cooperative Extension for Butte, Sutter, and Yuba counties

Previous research has documented the significant loss of rice straw forage quality during drying. At the time of harvest, energy values for rice straw can be near that of low-quality alfalfa but can decline quickly to a very low quality. The reasons for such dramatic changes are not well understood.

Haylage is the process of putting up forage under high moisture—45% to 65%. At the time of harvest, most rice straw is about 60% moisture. To clarify that the haylage process with rice straw utilizes harvest aftermath and not hay, researchers are calling it “strawlage.” Prior work on rice strawlage using plastic wrap on individual bales proved too costly. So field tests using tarps over bales were conducted at two ranches.

Rice straw was baled shortly after harvest at 49% moisture content at the Holzapfel ranch near Willows. Twenty one-ton bales were obtained from adjacent checks and stacked in the same north-south direction. A tarp covered three separate stacks—each received a different treatment.

One strawlage treatment was with a commercial hay preservative called Crop Saver™ that inhibits mold, fungi, and other microorganisms when baling at higher moistures than normal. A second strawlage treatment was with urea and UN 32 (a combination of urea and ammonium nitrate). The third stack received no treatment.

Core samples were taken when the strawlage was first put up and at 30, 60, 90, and 120 days after baling. Temperature, pH, density, and dry matter were analyzed at each sampling date.

A strawlage experiment also took place at the Ron LaGrande ranch near Williams. Bales from two checks were placed in two stacks.  One was treated with both UN 32 and urea, the other with a UN32 treatment on the outside of the stack only.

Strawlage treated with Crop Saver™ or the combination of urea and UN 32 did not have visible mold. At the Holzapfel ranch, even the control with no treatment appeared to have little mold. The field had been treated with Quadris®, which could have limited mold formation.

Preventing mold is an important first step in this line of research. At both locations the cattle aggressively consumed the strawlage.  Both ranches indicated they will use the process.  Utilization of strawlage may increase animal intake and, presumably, energy available to the cattle. Future research will examine animal intake and nutrition to assess any increase in forage value by this method of rice straw baling for cattle feed.