Abstract
We performed traction resistance measurement tests to elucidate the appropriate working condition for using a soil-removal type subsoil breaker (Plowsoiler; SUGANO Co. Ltd., hereafter in this study, this subsoil breaker will be referred to as “soil-removal type”) on Jahgaru soil, which is a type of a heavy clay soil found in Okinawa. The traction resistance measurement tests were performed using 2 types of soils (Jahgaru and Andisol) and 2 types of implements (a soil-removal type subsoil breaker and a subsoiler). Our results showed the traction resistance was increased exponentially with an increase in the depth. The average traction resistance of the soil-removal type subsoil breaker at the average work depth of 45-50 cm was approximately 20% and 40-50% in the Andisol and Jahgaru soils respectively; these values were observed to be lower than those obtained using the subsoiler. On the Jahgaru soil, tractor pitching increased linearly with an increase in the work speed of the subsoil breaker.
