Can rice straw be composted or used as mulch, or is there a risk of it sprouting? I have rice straw wattles that were used for an erosion and stormwater runoff control project which is now complete, and I’d like to use the straw in them.
I checked a couple of our books on grain growing, Homegrown Whole Grains by Sara Pitzer (Storey, 2009) and Small-Scale Grain Raising by Gene Logsdon (Rodale Press, 1977). Both of them refer to using rice straw as a mulch, Logsdon saying it makes an excellent mulch and Pitzer saying it can be left in the field to enrich the soil after the grain is harvested. In general, composting books don’t make any distinction between different types of straw, but caution against the use of hay because it may contain more seeds.
I don’t know which rice wattle product you used in your project, but some of them claim to be weed-free. You would certainly need to liberate the straw from the binding material (plastic netting or geotextile) which gives it its wattle shape before composting or mulching it. Another consideration is the source of the rice straw: if you are gardening organically, you will want to be sure that the rice was not treated with pesticides.
If you are curious about the nutrient balance in rice straw, University of California, Davis’s publication, “Rice Producers’ Guide to Marketing Straw,” October 2010, includes discussion of this issue.