The usefulness of Maleic Hydrazide (MH) as a grass growth retardant when applied to urban, suburban and rural roadsides was evaluated from 1961 through 1964. The material was also tested on "hard-to-maintain" areas such as fence lines. MH was applied at various rates, in the spring and fall with and without an herbicide (weed killer). The areas on which the material was applied are normally mowed from 2 to 11 times a year, depending on the areas.
The application of MH at six pounds active material per acre in the spring generally retarded the height of grass. Lower rates and fall applications were generally ineffective. Depending on the area (rural or urban) and the effectiveness of the application, between zero and five mowings per year were saved.
When the turf was of other than excellent quality and the MH application was effective, annual weeds such as crabgrass, foxtail and ragweed tended to become very evident. When MH was used without an herbicide the roadside generally appeared more ragged than when not treated. When MH was applied with an herbicide and annual weed invasion, did not occur, a satisfactory appearing roadside was obtained. The period of time in the spring during which MH can be effectively applied is short, about two weeks. Rains, winds and springtime maintenance activities make proper timing of the application work very difficult under Minnesota conditions.
The Minnesota Department of Highways, Minnesota Local Road Research Board and U.S. Department of Transportation established a one year investigation in 1968 to evaluate Plant Species Survival On Landscape Planting Projects. Thirty-six planting contracts installed in the five year period between 1963 and 1967 were reviewed. These projects were located throughout the state on Interstate, State Primary and County roads.
This study was designed to evaluate the survival of different plant species and clones installed. Factors that affect survival were studied and evaluated. Included were: soils, plant hardiness, planting design, geographic
location, drainage, contract requirements and administration, slope exposure, competition from other vegetation, and maintenance. Facts and findings resulting from this research study, covered in this report, will be implemented by the Highway Department and other agencies in improving future landscape planting work.
It was determined that the survival and vigorous growth of plant materials was the result of a combination of factors, but the most important factor was directly related to the timing and amount of water applied during and following the planting operation. Without sufficient moisture during the first growing season, many plants failed to become established. They either die or become stunted and eventually die in the following years.
This study was initiated to evaluate the performance of various seed mixtures, fertilizers, mulches and other products which are used in the control of vegetation and erosion on roadside areas
As will be noted from the General Introduction 16 years has passed since the project started. Formal field work was terminated in 1970. However, casual observations of the field plots, research areas, procedures and/or materials have continued until now. About 11 formal reports, published articles or formal paper presentations have resulted from the work Three revised Standards and Specification books with three supplements issued since the start of the present work reflect the findings, along with a revised construction manual.
A formal research project such as this one, formally funded by another agency, in this case the former Bureau of Public Roads (now the Federal Highway Administration) requires a formal project completion. This report is that document for this project.
Herewith is a copy of the interim report covering a portion of the work performed on this research project in 1963, 1964 and 1965.
The report includes further observations regarding some of the materials covered in the 1962 Report, "Experiments on Seeding and Mulching for Roadside Erosion Control". A section on erosion basics is included to provide background knowledge on this important, and often costly natural process.
The mulch experiment, reported herein has resulted in the addition of another material (green wood excelsior) to the specifications. This new material is supplied in bales and applied like straw, but it does not require an asphalt tack.
Seeding trials, species trials and some soil sterilant studies are also reported. The species work has resulted in the inclusion of birdsfoot trefoil in most of the seeding mixtures in the new specification book and in a wider use of crownvetch on specific sites.
