0.81 g/cm
3 on clayey shale and 1.18 g/cm
3 on clastic sediment). These were not
grouped for analysis, but the cultivated sites were compared individually based on
each parent material. All the sites were subject to compaction after land use
changed from forest to arable land, while bulk density was higher by 7 % in
cultivated soils on limestone, 23 % on clayey shale and 18 % on clastic sediments,
when compared to the reference sites. Compaction was thus observed between the
reference sites and cultivated sites.
When grouping all the soil profiles according to parent material – limestone
(n ¼ 5), clayey shale (n ¼ 5) and clastic sediment (n ¼ 19) – significant
differences were found in stocks of Corg, Nt and in bulk density. Stocks of Corg
were highest in soils on limestone (13.8 Æ 2.2 kg m
À2 ), followed by soils on clayey
shale (8.9 Æ 2.2 kg m
À2 ) and finally clastic sediments (5.8 Æ 2.6 kg m
À2 ). Stocks
of Nt were highest in soils on limestone (1.4 Æ 0.1 kg m
À2 ), followed by soils on
clayey shale (1.1 Æ 0.1 kg m
À2 ) and on clastic sediments (0.6 Æ 0.3 kg m
À2 ). Bulk
density in the clastic sediments (1.4 Æ 0.1 g/cm
2 ) was significantly different when
compared to the other two parent materials; however, between the limestone
(1.0 Æ 0.2 g/cm
2 ) and clayey shale (0.9 Æ 0.2 g/cm
2
) sites, bulk densities were
not significantly different.
S-values were not significantly different between the parent materials and
showed a large variation in the cases of clayey shale and clastic sediments. The
S-values were highest on limestone (128.6 Æ 15.5 mol m
À2 ), followed by clastic
sediments (81.1 Æ 65.2 mol m
À2 ) and clayey shale (72.8 Æ 59.4 mol m
À2 ).
Comparisons according to land use change and parent material revealed that both
variables were responsible for the degree of change in Corg, Nt, S-value and bulk
density figures. As the variation among reference sites was not high for Corg and
Nt, we conclude that land use change had a more pronounced influence on Corg and
Nt stocks than did parent material. The negative impact of erosion on soil bulk
density was strongest for soils derived from clastic sediments, followed by soils
derived from clayey shale.
2.6.4 Properties of Soils at Different Slope Positions
The effects of erosion are best detected based on landform, e.g., rills and gullies,
and soils exhibiting deposition, whereas soil profiles and the sequencing of horizons
are less effective. At the case study sites, parent materials were found to be deeply
weathered (saprolithe) and the solum thickness, even on steep slopes, was very deep
in general (>18 dm) and only shallow (<6 dm) on hill tops. No E-Horizons were
observed. The upper boundary of the argic horizons ranged from 12 to 16 cm in
most cases, but in two soils on the upper and lower slopes of catena 2, those with
soils derived from sandstone, it was only 5–6 cm. Buried horizons were found in
two soils at the base slope position for catenas 1 and 2 (profiles: catena 2 – basal
slope, catena 1 – basal slope/home garden), each having a colluvial horizon with a
thickness of 12.5 and 18 cm respectively. The higher organic material content down
2 Beyond the Horizons: Challenges and Prospects for Soil Science and Soil. . .
99
3 on clayey shale and 1.18 g/cm
3 on clastic sediment). These were not
grouped for analysis, but the cultivated sites were compared individually based on
each parent material. All the sites were subject to compaction after land use
changed from forest to arable land, while bulk density was higher by 7 % in
cultivated soils on limestone, 23 % on clayey shale and 18 % on clastic sediments,
when compared to the reference sites. Compaction was thus observed between the
reference sites and cultivated sites.
When grouping all the soil profiles according to parent material – limestone
(n ¼ 5), clayey shale (n ¼ 5) and clastic sediment (n ¼ 19) – significant
differences were found in stocks of Corg, Nt and in bulk density. Stocks of Corg
were highest in soils on limestone (13.8 Æ 2.2 kg m
À2 ), followed by soils on clayey
shale (8.9 Æ 2.2 kg m
À2 ) and finally clastic sediments (5.8 Æ 2.6 kg m
À2 ). Stocks
of Nt were highest in soils on limestone (1.4 Æ 0.1 kg m
À2 ), followed by soils on
clayey shale (1.1 Æ 0.1 kg m
À2 ) and on clastic sediments (0.6 Æ 0.3 kg m
À2 ). Bulk
density in the clastic sediments (1.4 Æ 0.1 g/cm
2 ) was significantly different when
compared to the other two parent materials; however, between the limestone
(1.0 Æ 0.2 g/cm
2 ) and clayey shale (0.9 Æ 0.2 g/cm
2
) sites, bulk densities were
not significantly different.
S-values were not significantly different between the parent materials and
showed a large variation in the cases of clayey shale and clastic sediments. The
S-values were highest on limestone (128.6 Æ 15.5 mol m
À2 ), followed by clastic
sediments (81.1 Æ 65.2 mol m
À2 ) and clayey shale (72.8 Æ 59.4 mol m
À2 ).
Comparisons according to land use change and parent material revealed that both
variables were responsible for the degree of change in Corg, Nt, S-value and bulk
density figures. As the variation among reference sites was not high for Corg and
Nt, we conclude that land use change had a more pronounced influence on Corg and
Nt stocks than did parent material. The negative impact of erosion on soil bulk
density was strongest for soils derived from clastic sediments, followed by soils
derived from clayey shale.
2.6.4 Properties of Soils at Different Slope Positions
The effects of erosion are best detected based on landform, e.g., rills and gullies,
and soils exhibiting deposition, whereas soil profiles and the sequencing of horizons
are less effective. At the case study sites, parent materials were found to be deeply
weathered (saprolithe) and the solum thickness, even on steep slopes, was very deep
in general (>18 dm) and only shallow (<6 dm) on hill tops. No E-Horizons were
observed. The upper boundary of the argic horizons ranged from 12 to 16 cm in
most cases, but in two soils on the upper and lower slopes of catena 2, those with
soils derived from sandstone, it was only 5–6 cm. Buried horizons were found in
two soils at the base slope position for catenas 1 and 2 (profiles: catena 2 – basal
slope, catena 1 – basal slope/home garden), each having a colluvial horizon with a
thickness of 12.5 and 18 cm respectively. The higher organic material content down
2 Beyond the Horizons: Challenges and Prospects for Soil Science and Soil. . .
99