PROBLEMS IN ESTABLISHING OR MAINTAINING VEGETATION ON ROADSIDES

TESTS WERE INSTALLED DURING 1968-70 TO INVESTIGATE THE MODIFICATION OF ROADSIDE SOIL MATERIALS RESTRICTED BY PHYSICAL OR CHEMICAL CHARACTERISTICS LIMITING PLANT GROWTH, TO DETERMINE THE UTILITY OF PLANT MATERIALS FOR ROADSIDE USE, AND TO DEVELOP CHEMICAL TREATMENTS FOR CONTROLLING UNWANTED VEGETATION. A PLASTICITY INDEX (PI) VALUE GREATER THAN 16 SIGNIFIES A POOR TENDECNY TOWARD GRANULATION AND OTHER PROPERTIES DESIRABLE IN A PLANT GROWT MEDIUM. THIS PHYSICAL CONDITION CAN BE MODIFIED IN SOME, BUT NOT ALL, CASES BY ADMIXING AGRICULTURAL GYPSUM, CERTAIN CATIONIC POLYMERS AND POLYURETHANE. SEDIMENTS CONTAINED IN MATERIALS FROM THE WECHES AND QUEEN CITY FORMATIONS MAY SHOW PH AS LOW AS 1.8. THIS EXTREME ACIDITY CAN BE NEUTRALIZED BY LIME APPLICATIONS AS HIGH AS 50 TONS PER ACRE, BASED ON POTENTIOMETRIC TITRATION, TO ESTABLISH A VEGETATIVE COVER. MAINTENANCE SURFACE LIME APPLICATIONS, BEGINNING 3 YEARS AFTER INITIAL TREATMENT, WILL BE REQUIRED TO RETAIN THE SOD COVER. SEEDINGS IN TEXAS FOR EROSION CONTROL CAN BE EXTENDED TO THE 15-INCH ISOHYET PROVIDED THE SOIL MATERIAL IS SANDY, NOT EXTREMELY SALINE, AND COMPETITIVE PLANTS ARE CONTROLLED. BUFFALOGRASS, AT THIS TIME, SHOULD BE SEEDED IN A MIXTURE OF OTHER MATERIALS ADAPTED TO NORTHWESTERN TEXAS, RATHER THAN ALONE. PERENNIAL WEEDS GROWING IN SHOULDER PAVEMENTS WERE CONTROLLED BY PROGRAM SPRAYS OF FENAC-DICAMBA COMBINED WITH EITHER PROMETONE OR BROMANIL. MOWING ADJACENT TO MEDIAN PLANTINGS MAY BE FACILITATED BY A COMBINATION CONTACT- PRE-EMERGENCE TREATMENT.

  • Supplemental Notes:
    • 18 PP
  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  United States  76011
  • Authors:
    • Mccully, W
    • Bowmer, W
    • Stubbendieck, J
  • Publication Date: 1970-12

Subject/Index Terms

Filing Info

  • Accession Number: 00204648
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Files: TRIS, ATRI, USDOT
  • Created Date: Jun 28 1972 12:00AM