The objective ''hay in a day'' can be realized by the mat harvesting technique. The processing of forage through severe damaging of cuticle and formation of thin mats allows a safe moisture level to be reached in one day. The macerator used in this research consists of a toothed main cylinder and six counter rotating rolls. The macerator was tested first in a stationary experimental system to obtain design data for a prototype. Subsequently, a towable macerator was designed and built. Mowing and pressing units will be designed in further work. Drying experiments showed that a safe moisture content of under 20% m.c.w.b. could be reached in 5 to 6 h using the mat formation technique in the Cukurova region. (C) 1997 Silsoe Research Institute.