The pilot submitted a written statement. He indicated that he was landing at a 1,800-foot long grass airstrip. The pilot flared the airplane approximately one-fourth of the way down the runway, the airplane bounced, and he added power to soften the second touchdown. The pilot felt that a go-around was too dangerous so he applied the brakes. Just as the airplane came to a stop, it slid into a ditch at the end of the runway. The pilot and a friend built the airplane and he had flown about 10 hours in it. He stated that he should have been more familiar with the short-field landing characteristics of this particular airplane. He had been into the airstrip numerous times in his other airplane of the same make/model, but the previous airplane was equipped with a constant speed propeller and seemed to float less down the runway.