Table 1 Mineralogical combinations and their related amount of aluminous clay (clay) and dithionite-citrate-bicarbonate-extractable Fe (Fe_d), and respective Fe_d to aluminous clay ratios (Fe_d/clay).

Forest

Low aluminous clay‒

0‒5

149^b (19)

21^d (4)

0.15^b,A (0.04)

76.0^ab,A (27.4)

27.1^a,A (2.9)

Low pedogenic Fe oxides

5‒10

181^b (19)

38^b (13)

0.21^bc,A (0.09)

34.1^a,A (6.2)

23.2^ab,A (5.5)

Forest

Low aluminous clay‒

0‒5

182^b (38)

78^a (14)

0.45^a,A (0.12)

57.3^b,A (14.4)

36.0^a,A (4.9)

High pedogenic Fe oxides

5‒10

174^b (42)

77^a (4)

047^a,A (0.13)

37.2^a,A (6.6)

28.3^a,B (5.3)

Forest

High aluminous clay‒

0‒5

298^a (41)

36^c (5)

0.12^b (0.01)

43.2^b (6.1)

24.5^a (1.1)

Low pedogenic Fe oxides

5‒10

374^a (24)

44^b (7)

0.12^c (0.02

23.0^b (5.0)

14.6^c (0.8)

Forest

High aluminous clay‒

0‒5

318^a (41)

67^b (5)

0.22^b,A (0.03)

95.1^a,A (31.1)

36.1^a,A (15.7)

High pedogenic Fe oxides

5‒10

349^a (40)

81^a (6)

0.23^b,A (0.02)

34.9^a,A (4.5)

22.6^b,A (2.6)

Cropland

Low aluminous clay‒

0‒5

227^b (6)

30^c (2)

0.13^b,A (0.01)

18.7^c,B (0.2)

10.5^c,B (2.7)

Low pedogenic Fe oxides

5‒10

213^b (24)

29^c (4)

0.14^b,A (0.03)

18.8^c,B (1.3)

13.7^c,B (0.2)

Cropland

Low aluminous clay‒

0‒5

198^b (29)

101^a (4)

0.51^a,A (0.06)

47.1^a,A (0.9)

38.2^a,A (4.7)

High pedogenic Fe oxides

5‒10

215^b (23)

100^a (5)

0.47^a,A (0.07)

48.1^a,A (4.8)

36.7^a,A (1.3)

Cropland

High aluminous clay‒

0‒5

434^a (18)

63^b (3)

0.15^b,B (0.01)

33.7^b,B (1.2)

20.0^b,A (0.9)

High pedogenic Fe oxides

5‒10

438^a (17)

66^b (4)

0.15^b,B (0.01)

28.9^b,A (2.9)

18.8^b,A (3.0)