An alternative to burial for cables is to run them through pipes laying on the ground. The pipes provide protection for the cable inside from physical impact damage but must be somehow held in place so they don't get shifted sideways by people or vehicle tires.

Irrigation pipes are one possible source for local pipe. If using metal pipes I would try to find some plastic pipe or hose to sleeve inside to keep the network cables from touching the metal pipe walls and avoid cable damage from sharp edges where the metal pipe sections join.

I wish you well with your project.

One method to pull cables through a long pipe is to use a vacuum cleaner at one end to suck a soft ball or sponge with a long string attached. The ball draws the thin string through the pipe, then attach a stronger rope to the string. Pull that through, then use the rope to pull the cables through. Draw another thin string through with the cables so that you can pull another cable later, should the need arise.

To reduce friction while pulling the cables through, dribble dish washing liquid hand soap onto the cable as it enters the pipe. The soap acts as a lubricant but should not attack the plastic materials of the cables. Grease and petroleum products should not be used with electrical and networking cables.