Objective

Develop economical systems of crop residue management which enhance environmental quality

Our residue management research, cooperatively planned and conducted with the California Air Resources Board and the Solid Waste Management Board, has clearly demonstrated to the public our long-term interest in maintaining good environmental conditions. This research has enabled us to retain field burning as a management tool to control stem rot and has provided information on other residue management practices.

The now widely-used strip, into-the-wind firing method of burning rice fields to con trol stem rot disease organisms and reduce straw to manageable levels was developed by UCD agricultural engineers George Miller, John Goss and Jim Thompson. This procedure reduces atmospheric emissions by 50 to 90 percent.

 

Most studies on utilizing rice straw for fuel or livestock feed have concentrated on ways to gather, transport, and stockpile straw. At current costs, fuels such as coal have proved to be far more economical energy sources than straw delivered to point of use. UCD and USDA scientists have found that rice straw treated with sodium hydroxide or ammonium compounds becomes a useable roughage for sheep, beef and dairy cattle. Research has recently been funded to attempt to convert rice straw into sugar syrup.

 

Many systems of incorporating straw into the soil were tried by UCD agricultural engineers. Chopping straw into 11/2- to 4-inch lengths before incorporation facilitated the process and speeded decomposition. Complete fall soil incorporation of rice straw reduces stem rot buildup but is not as effective as burning. The studies by Drs. Robert A. Kepner and John B. Dobie showed that the best of incorporation methods may cost up to 150 times more than disposing of straw by open field burning.