ADAPTATION OF CERTAIN HERBACEOUS MATERIALS FOR HIGHWAY SLOPE CONTROL

PROBLEMS RELATED TO THE ESTABLISHMENT OF VEGETATION TO CONTROL EROSION ON ROADSIDE AREAS WERE STUDIED AT PENN STATE'S ENGINEERING EXPERIMENT STATION. FACTORS CONSIDERED WERE: ADAPTABILITY OF CERTAIN GRASSES AND LEGUMES FOR SLOPE EROSION-CONTROL PURPOSES, RATES OF APPLYING GRASS SEED-HAY, EFFECT OF DATES OF SEEDING AND SLOPE EXPOSURE ON THE SEEDLING POPULATION, AND THE DEVELOPMENT OF A SATISFACTORY GROUND COVER FROM A MIXTURE OF ONE GRASS AND ALL COMBINATIONS OF TWO GRASSES AND A LEGUME. THE STUDY OF ADAPTABILITY OF HERBACEOUS MATERIALS WAS MADE ON AN EXPERIMENTAL AREA HAVING A SOUTHERN EXPOSURE WITH A GRADIENT FROM 1:1 TO 2:1 NEAR PORT MATILDA, PENNSYLVANIA. THE DURATION OF THE EXPERIMENT WAS FROM THE FALL OF 1947 THROUGH THE FALL OF 1950. EXCELLENT GROUND COVER WAS PRODUCED IN THREE YEARS. GROUND COVER PRODUCED BY INDIVIDUAL GRASSES DURING THE THREE-YEAR PERIOD WAS IN THE FOLLOWING ORDER FROM HIGHEST TO LOWEST PERCENT: (1) CREEPING RED FESCUE, (2) ALTA FESCUE, (3) TALL OATGRASS (4) ORCHARDGRASS, AND (5) POVERTY OATGRASS. (3) CROWN VETCH WITH ORCHARDGRASS, RED FESCUE, AND ALTA FESCUE, SHOWED HIGHEST PERCENT PLANT SURVIVAL FROM SUMMER SEEDINGS; WITH DOMESTIC RYEGRASS FROM WINTER SEEDING; AND WITH TALL OATGRASS FROM SPRING SEEDING. SUMMER SEEDING GAVE THE HIGHEST AVERAGE PERCENT CROWN VETCH PLANT SURVIVAL; DOMESTIC RYEGRASS GAVE THE HIGHEST AVERAGE PERCENT PLANT SURVIVAL FOR ALL THREE SEASONS. /AUTHOR/