Straw Mulching
The Straw Mulching process is a three-step operation.
First, the area requiring revegetation is seeded by hydroseeding, or by tractor drawn equipment such as seed drills or spinner broadcasters if the area is readily accessible.
A layer of chopped cereal straw is blown over the seeded area, using a specially manufactured straw-blower unit, and the resulting straw mat is approximately 20mm thick. Cereal straw is used to avoid the introduction of weed seed, because meadow hay or grass hay can contain several species of weeds.
Finally, a spray of anionic slow-setting Bitumen Emulsion is sprayed over the straw to form a cohesive blanket. By spraying the straw with a hand held hose the bitumen can be placed more accurately to avoid overspraying of kerbs, fences, and other structures.
The mat formed by the chopped straw and bitumen emulsion retains moisture and warmth around the seed promoting germination.
Bitumen straw mulch is easily damaged by pedestrian and vehicular traffic which breaks the bitumen bond between the straw particles, and this allows wind damage to occur. Treated areas should always be protected against traffic by barriers and signs.