Effect of fertilizer applications and grazing exclusion on species composition and biomass in wet meadow restoration in eastern Washington.

Fertilizer applications and grazing exclusion were used as restoration strategies in degraded wet meadows in eastern Washington to grow biomass in the root systems where it could not be grazed. We used a split-block design to test vegetation responses to six fertilizer rates, eight fertilizer types, and three grazing treatments after three growing seasons. Little change in plant composition was detected, but weed biomass was reduced by 50 percent in cattle plus elk grazing. Although forb shoot biomass did not increase, grass shoot biomass doubled but was influenced by grazing treatments. Root biomass doubled under fertilizer applications. A 10-percent decline in soil bulk density suggested a reduction in soil compaction. These responses were attributed to the increased root biomass. Optimum fertilization rates of 100 kg/ha were recommended along with carefully administered grazing schedules for meadow community restoration.