Use of biosolids to enhance rangeland forage quality.
Biosolids land application was demonstrated to be a potentially cost-effective means for restoring forage productivity and enhancing soil-moisture-holding capacity on disturbed rangelands. By land-applying aerobically digested, anaerobically digested, composted, and lime-stabilized biosolids on rangeland test plots at rates of up to 20 times (20X) the estimated nitrogen-based agronomic rate, forage yields were found to increase from 132.8 kg/ha (118.2 lb/ac) (control plots) to 1182.3 kg/ha (1052.8 lb/ac). Despite the environmental benefits associated with increased forage yield (e.g., reduced soil erosion, improved drainage, and enhanced terrestrial carbon sequestration), the type of forage generated both before and after biosolids land application was found to be dominated by invasive weeds, all of which were characterized as having fair to poor nutritional value. Opportunistic and shallow rooting invasive weeds not only have marginal nutritional value, they also limit the establishment of native perennial grasses and thus biodiversity. Many of the identified invasive species (e.g., Cheatgrass) mature early, a characteristic that significantly increases the fuel loads that support the increased frequency and extent of western wildfires.
McFarland
Michael J
MJ
U.S. Environmental Protection Agency, Region 8, Denver, Colorado, USA. farlandm@msn.com
Vasquez
Issaak Romero
IR
Vutran
MaiAnh
M
Schmitz
Mark
M
Brobst
Robert B
RB
D003247:Conservation of Natural Resources / Q000379:methods*; D005308:Fertilizers; D063245:Plant Development; D012722:Sewage; D012987:Soil; D014481:United States; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water
D005308:Fertilizers; D012722:Sewage; D012987:Soil; D014867:Water