RANGELAND RESTORATION RESEARCH
Restoring Grasslands in the Chihuahuan Desert Using Cotton Bur/Burlap Wattles
A healthy rangeland is reliant upon retaining moisture in the soil. This is especially a concern in arid regions, such as the Chihuahuan desert. A wattle is a small man-made water obstruction that can help to reduce runoff and erosion and increase soil infiltration by rainwater. This increased infiltration makes more water available for vegetation growth, spring and creek flow, and ground water recharge.
While there are commercially available wattles, they can be quite expensive, and they are not ideal for use in a rangeland setting, as the material they are made of is not fully biodegradable, and installation requires digging a trench to avoid water flowing under the wattle. Given the highly erodible nature of many habitats in west Texas, we initiated research to determine the feasibility of constructing, installing and using biodegradable wattles as a restoration technique on a Brewster county grassland. Our objectives were to increase infiltration rates by slowing down runoff without using a highly intrusive technique and to begin revegetation of desirable species in order to maintain improvements.
Wattles were constructed of 100% biodegradable burlap bags filled with cotton burs. The wattles were laid along contour lines every 33 meters within the study site, and bands above each wattle were harrowed and reseeded with native species. Half of the wattles were kept in place by wooden stakes, and the other half by the more intrusive technique of bulldozing a small trench to support the wattles.
While the bulldozed treatment site showed the highest percent soil moisture, gain in soil height, and amount of revegetation, the staked treatment also showed increased soil moisture and revegetation as compared to the control site where no wattles were installed. We found that the wattles were successful at creating a microclimate conducive for seedling germination on a site where germination would not otherwise occur. This method shows promise as an affordable restoration technique for west Texas rangelands.