Characterisation of soils under long-term crop cultivation without fertilisers: a case study in Japan

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Table 3 Profile descriptions for the four soils on Eniwa and Narita farms

Horizon	Depth (cm)	Colour	Texture (USDA)	Rock fragments^a	Structure^b	Compactness^c (MPa)	Roots^d
E-UF
Oi	+1–0
Ap	0–9	10YR2/1	SL	W/C	3/M/Cr	0.096	Vf/M, F/Vf
A1	9–25	10YR2/1	SL	W/C	3/F/Cr, 2/M/Sb	0.137	Vf/M, F/Vf
A2	25–40	10YR2/1	SL	W/C	3/M/Cr, 2/M–C/Sb	0.296	Vf/M, F/Vf, M/F
2A3	40–55	10YR1.7/1	CL	None	2/F/Sb	0.396	VF/C, F/F
3AB	55–75	10YR2/2	CL	ST/M	2/F–C/Sb	0.617	Vf/F, F/Vf
4Bw	75–100+	10YR4/6	L	ST/A	2/F–C/Sb	1.156	None
E-CF
Ap1	0–12	10YR2/1	SL	W/C	3/F–C/Cr	0.161	Vf/C, F/Vf
Ap2	12–30	10YR2/1	SL	W/C	2/F–C/Cr	0.116	Vf/C, F/F, M/Vf
Ap3	30–40	10YR2/1	SL	W/A	2/F–C/Cr, 1/M–C/Sb	0.342	Vf/F, F/Vf
2A	40–50	10YR1.7/1	CL	ST/F	2/M–C/Sb	0.718	Vf/Vf
3AB	50–70	10YR3/4	CL	ST/M	2/M–C/Sb	0.532	Vf/Vf
4Bw	70–100+	10YR4/6	SL	ST/A	1/C/Sb	1.370	None
N-UF
Ap	0–8	7.5YR2/3	SIC	None	3/F/Cr, 1/M/Sb	0.038	Vf/M, F/M
A1	8–21	7.5YR2/2	C	None	2/F–C/Sb	0.459	Vf/M, F/M
A2	21–45	7.5YR2/2	C	None	2/F–C/Sb	0.459	Vf/F, F/F
AB	45–61	7.5YR3/2	SIC	None	2/F–C/Sb	0.396	Vf/F, F/F
Bw1	61–87	7.5YR4/4	SIC	None	2/F–C/Sb	0.459	Vf/F, F/F
Bw2	87–100+	7.5YR4/6	SIC	None	2/F–C/Sb	0.718	Vf/F, F/F
N-CF
Ap	0–17	7.5YR2/2	C	None	3/M/Cr	0.050	Vf/F, F/F
A1	17–30	7.5YR2/2	C	None	2/F–C/Sb	1.636	Vf/VF
A2	30–44	7.5YR3/2	SIC	None	2/F–C/Sb	0.396	Vf/F, F/F
AB	44–62	7.5YR4/4	SIC	None	2/F–C/Sb	0.617	Vf/VF, F/Vf
Bw	62–100+	7.5YR4/6	SIC	None	2/F–C/Sb	0.718	Vf/Vf, F/Vf

Profiles are described according to a soil description system of United Soil Classification System of Japan (The Fourth Committee for Soil Classification and Nomenclature in the Japanese Society of Pedology 2010)
^aState of wethering (W weathered, ST strongly weathered)/abundance (F few, C common, M many, A abundant), all rock fragments were gravel or stone size and shape ware rounded
^bGrade (1: weak, 2: moderate, 3: strong)/size (F fine, M medium, C course)/type (Cr crumb, Sb subangular blocky)
^cCompactness was measured by using soil hardness tester (DIK-5553, Daiki)
^dSize (Vf very fine, F fine, M medium)/abundance (Vf very few, F few, C common, M many)