The owners or operators of any pipelines for which any right-of-way is obtained under the provisions of this act shall be entitled to erect and construct a telephone or telegraph line upon and along such right-of-way for use in the operation of such pipeline, and shall not be required to operate said telegraph or telephone line as a toll line, or to open same to the use of the public; provided, that the construction and maintenance of said telephone or telegraph line shall not unduly interfere with the cultivation of any agricultural land.