with front-mounted loader, a tractor New Holland T-5060
was used. Front-mounted loader MX 10 was mounted on
the tractor, as well as 500 kg ballast mass on the rear
hydraulic lift. Fig. 1 represents the general shape of the
tractor-loader unit that was used for the study, and in
Table 1 characteristics and indicators of this unit are
presented.
The standard test methodologies were not followed
strictly, because the intention was to test variation in tire
interaction with terrain rather than variation in draft and
its maximum value.
Tests were carried out on a plain clover stubble field by
moving in a straight path. Stubble height did not exceed 3–
6 cm. The soil was light loam. The cone index in 5–15 cm
depth was 1.14–1.75 MPa. The soil moisture content on
the test field varied between 9.05% and 16.15%. The
detailed specifications of measurement devices are presented
in Table 2.