Abstract
The authors reported a new ploughless method mainly using new machines. The main improvements of this method were cutting and crushing of native vegetation on the site for preparation of seedbed rich in crushed wood fragments. This method combined using a stumpcutter (SC) to cut stumps with bushcutter (BC) to crush bushes. The basic part of SC was a hydraulic shovel which was ordinarily used as an excavator in civil engineering work. Two scissor-like cutting edges were installed on the bracket part of the excavator in such a was as to be able to open and shut. This cutter was inserted around the stump and cut it. The BC was used to cut and crush young trees and tall bushes. At the same time it stirred the soil about 5cm below the surface, so it also cut and crushed rhizomes and roots of native perennial grasses. The limiting inclinations of operating of SC and BC were about 25 and 30°, respectively. The cutting time of SC was about 2.5min per stump and the total operating time was about 687min/ha. The total operating time of BC was about 35h/ha in the condition of repeated twice treatments. Most of the crushed wood fragments were less than 10cm in length after the treatment. This new method had no process of transferring of stumps, cut-branches and -trunks as well as soils. The altitude and roughness of the ground were almost the same as those established before. There was 581.9mm of precipitation in 29 times during 4 months after the establishment. However, soil erosion and the transfer of crushed wood fragments were not observed. There were no stumps and lines of excluded wood roots in the pasture so that tractor could be used freely.
