七吋步犁犁身较长,小块土地中操作及转向时较困难,贵州群众使用不习惯,希望改短使用。1954年,贵州省农具药械实验站根据七吋步犁设计原理,结合贵州耕畜以牛为主,牛的拉力点较骡、马的拉力点低些;马多用长套绳,牛习惯短套绳;及农村使用旧式犁等情况进行了犁身改短的研究试验,获得成功。改短后的七吋 Seven-inch plow plow longer, small land operation and steering more difficult, Guizhou people are not accustomed to use, hoping to shorten the use. In 1954, according to the seven-inch step-plow design principle and the principle of Guizhou poultry farming, Guizhou’s farm machinery and pharmacy experimental station was mainly dominated by cattle. The pulling force of the cattle was lower than that of the mules and the horse’s pulling force. Rope; and the use of the old plow and other rural areas of the plow to shortening the research trials, success. Seven inches shorter