The 148-hour private pilot lost control of the single-engine airplane while landing on a private turf airstrip. The pilot reported that while landing on runway 9, which was reported as a 2,000-foot long by 20-foot wide turf and concrete runway, the wheel brakes did not properly respond to his input. The pilot added in the accident report (NTSB Form 6120.1/2) that "during my ground roll, I attempted to apply the brakes. I noted no braking. I pumped the brake pedal and then noted slight braking in the right wheel only." The airplane continued beyond the departure end of the runway, which was described as wet and muddy, until impacting a small ditch and coming to rest in the inverted position. The pilot exited the airplane from the canopy window without injuries. Weather reported at the Slidell Airport, located approximately 20 miles west of the accident location, was clear skies, 10 miles visibility, with light and variable winds.