Variation in soil properties under different land use types managed by smallholder farmers in central Ethiopia

Figures & data

Figure 1. Location map of the study area.

Figure 2. Climatic condition of the study area (Source: NMSA, 2015).

Figure 3. Soil sampling points from the five different land use systems; WL = wood lot; EF: enset field; GL: grazing land; FL: annual crops field (farmland).

Figure 4. Open and closed grazing lands are located close and far from homestead.

Figure 5. Enset system receives large amount of organic inputs.

Table 1. Description of the studied land use types in the central highlands of Ethiopia

Land use	Description
Enset system	Enset system is field located close to home and used for growing enset plant and often fertilized with manure and other household waste for more than 50 years. Enset is a perennial herbaceous species of flowering plant in the banana family, Musaceae and one of the staple crops which has been feeding about 20 million peoples in southern Ethiopia. It also hosts diverse multipurpose tree, shrub as well as crops and grass.
Closed grazing land	Closed grazing land is privately owned pasture land located far from home. Served as pasture land for more than 50 years. It is used as closed grazing land in wet season (June-November) and open grazing land in dry season. It is located down the slopes; hence it is subjected to waterlogging during wet season.
Open grazing land	Open grazing land is privately owned pastureland, located close to home and used as open grazing land for more than 25 years. It is established on the degradedfarm land and often few park land trees are retained where the cattle use as shade during the day time.
Eucalyptus Woodlots	Woodlot is small-scale plantation of Eucalyptus camaldulensis. It is established on the degraded cropped land where farmers abandoned because of their poor soil fertility some 15–17 years ago.
Cereal farmland	Cereal farmland is a low input cereal cropping system, located far from home and dominantly used for growing annual cereal crops such as wheat, teff, and maize. The field has been used for cereal farming for more than 50 years and fertilized with inorganic fertilizers (DAP and Urea). It is intensively and frequently plowed, and crop residues are often removed for feed and fuel.

Table 2. Soil physical properties across different land use types at 0 − 45 cm soil depth in central Ethiopia

Soil property	Land use types
	Enset System	Closed grazing land	Open grazing land	Eucalyptus Woodlots	Cereal farmland
Clay (%)	35 ± 1.85b	40.9 ± 1.96a	35.7 ± 1.95ab	35.7 ± 1.95ab	41.96 ± 1.25a
Silt (%)	35 ± 2a	35.3 ± 2.2a	37.88 ± 2.2a	38.5 ± 2a	30.64 ± 2a
Sand (%)	30 ± 2a	23.57 ± 2.2a	26.44 ± 2.2a	25.67.4 ± 2a	27.39 ± 2a
Textural class	Clay loam	Clay loam	Clay loam	Clay loam	Clay loam
MC (%)	31.1 ± 1.19ab	34.79 ± 1.19a	29.9 ± 1.19c	26.14 ± 1.19c	32.41 ± 1.19 ab
BD (g cm^−3)	1.15 ± 0.09ab	1.14 ± 0.09a	1.19±±0.09ab	1.15 ± 0.09ab	1.23 ± 0.09a

*Values followed by the same letters in a row are not significantly different at P < 0.05; MC and BD refer to moisture content and bulk density, respectively

Table 3. Soil chemical properties across different land use types at 0 − 45 cm soil depth in central Ethiopia

Soil property	Land use types
	Enset system	Closed grazing land	Open grazing land	Eucalyptus Woodlots	Cereal farmland
OC (%)	2.48 ± 0.67a	2.23 ± 0.98ab	1.67 ± 0.63c	1.79 ± 0.44bc	1.39 ± 0.3c
TN (%)	0.21 ± 0.06a	0.20 ± 0.08ab	0.14 ± 0.06c	0.16 ± 0.04bc	0.12 ± 0.03c
Av. P (mg kg^−1)	187.52 ± 15.8a	18.12 ± 1.5b	62.49 ± 10.2b	52.55 ± 5.5b	44.87 ± 5.6b
pH	6.38 ± 0.46a	5.81 ± 0.64ab	6.12 ± 0.57ab	5.61 ± 0.57b	5.82 ± 0.64ab
K+ (cmole kg^−1)	1.63 ± 0.46a	0.32 ± 0.02b	0.85 ± 0.26ab	0.68 ± 0.03ab	0.58 ± 0.04ab
CEC (cmole kg^−1)	29.45 ± 1.03a	29.64 ± 0.85a	28.93 ± 1.09a	29.03 ± 0.7a	29.09 ± 0.88a

*Values followed by the same letters in a row are not significantly different at P < 0.05; where OC ‒ organic carbon; TN ‒ total nitrogen, Av P ‒ available phosphorus; K+ ‒ exchangeable potassium; and CEC ‒ cation exchange capacity

Table 4. Effects of land use types on soil organic carbon (SOC) and total nitrogen (TN) stocks in central Ethiopia

Soil Property	Soil depth (cm)	Land use types
		Enset system	Closed grazing land	Open grazing land	Eucalyptus Woodlots	Cereal farm land
SOC (Mg/ha)	0–15	49.41 ± 2.0	49.25 ± 5.58	36.47 ± 7.8	37.17 ± 4	27.59 ± 2.24
	15–30	43.11 ± 4.91	32.67 ± 2.5	28.06 ± 2.35	29.15 ± 2.16	25.34 ± 3.38
	30–45	34.86 ± 4.17	26.15 ± 1.90	24.05 ± 2.13	26.23 ± 1.46	23.72 ± 6.97
	Mean	42.45 ± 2.5a	36.02 ± 2.8ab	29.52 ± 2bc	30.85 ± 1.8bc	25.55 ± 1.3c
	Total	127.36 ± 7.54a	108.07 ± 8.7ab	88.57 ± 7.97bc	92.55 ± 5.54bc	76.65 ± 3.8c
TN (Mg/ha)	0–15	4.11 ± 0.4	4.31 ± 0.5	3.18 ± 0.68	3.23 ± 0.0.32	2.49 ± 0.0.26
	15–30	3.55 ± 0.68	2.76 ± 0.3	2.32 ± 0.22	2.47 ± 0.2	2.12 ± 0.18
	30–45	2.94 ± 0.36	2.4 ± 0.47	2.06 ± 0.16	2.34 ± 0.14	2.13 ± 0.18
	Mean	3.53 ± 0.21a	3.16 ± 0.12ab	2.52 ± 0.25bc	2.68 ± 0.16bc	2.25 ± 0.32c
	Total	10.6 ± 0.69a	9.47 ± 0.72ab	7.56 ± 0.69bc	8.04 ± 0.45bc	6.73 ± 0.36c

*Values followed by the same letters in a row are not significantly different at P < 0.05; where SOC ‒ Soil carbon stock; TN ‒ Total nitrogen stocks

Analysis of Variance (ANOVA) for soil bulk density.

Source	Df	Mean Square	F	Sign.
Corrected Model	14.00	0.05	3.90	0.00
Intercept	1.00	132.93	10,403.93	0.00
LUT	4.00	0.03	2.57	0.04
Soil depth	2.00	0.19	14.65	0.00
LUT * Soil depth	8.00	0.03	2.19	0.06
Error	84.00	0.01
Total	99.00
Corrected Total	98.00

Analysis of Variance (ANOVA) for clay content.

Source	Df	Mean Square	F	Sign.
Corrected Model	14.00	78.24	1.80	0.06
Intercept	1.00	95,094.38	2193.24	0.00
LUT	4.00	174.91	4.03	0.01
Soil depth	2.00	102.92	2.37	0.10
LUT * Soil depth	8.00	22.57	0.52	0.84
Error	54.00	43.36
Total	69.00
Corrected Total	68.00

Analysis of Variance (ANOVA) for silt content

Source	df	Mean Square	F	sign
Corrected Model	14.00	72.08	1.34	0.22
Intercept	1.00	84,485.84	1571.17	0.00
LUT	4.00	130.32	2.42	0.06
Soil depth	2.00	69.72	1.30	0.28
LUT * Soil depth	8.00	40.78	0.76	0.64
Error	53.00	53.77
Total	68.00
Corrected Total	67.00

Analysis of Variance (ANOVA) for sand content

Source	Df	Mean Square	F
Corrected Model	14.00	45.07	1.58	0.12
Intercept	1.00	46,555.52	1626.95	0.00
LUT	4.00	60.63	2.12	0.09
Soil depth	2.00	0.56	0.02	0.98
LUT * soil depth	8.00	42.80	1.50	0.18
Error	53.00	28.62
Total	68.00
Corrected Total	67.00

Two-Way Analysis of Variance (ANOVA) for exchangeable K

Source of variation	Df	Mean Square	F	Sing
Corrected Model	14.00	1.30	1.39	0.19
Intercept	1.00	45.50	48.64	0.00
LUT	4.00	3.25	3.47	0.01
Soil depth	2.00	0.80	0.86	0.43
LUT * Soil depth	8.00	0.37	0.40	0.92
Error	53.00	0.94
Total	68.00
Corrected Total	67.00

Analysis of Variance (ANOVA) for CEC level

Source variation	Df	Mean Square	F	Sign.
Corrected Model	14.00	14.57	1.26	0.26
Intercept	1.00	59,927.86	5175.47	0.00
LUT	4.00	7.02	0.61	0.66
Soil depth	2.00	16.33	1.41	0.25
LUT * Soil depth	8.00	17.79	1.54	0.17
Error	55.00	11.58
Total	70.00
Corrected Total	69.00

Analysis of Variance (ANOVA) for organic carbon content

Source	Df	Mean Square	F	Sign.
Corrected Model	14.000	2.697	12.156	0.000
Intercept	1.000	362.447	1633.831	0.000
LUT	4.000	3.711	16.730	0.000
Soil depth	2.000	9.404	42.391	0.000
LUT * Soil depth	8.000	0.753	3.392	0.002
Error	84.000	0.222
Total	99.000
Corrected Total	98.000

Analysis of Variance (ANOVA) for total nitrogen content

Source	Df	Mean Square	F	Sign.
Corrected Model	14.000	0.019	12.254	0.000
Intercept	1.000	2.675	1750.397	0.000
LUT	4.000	0.024	15.592	0.000
Soil depth	2.000	0.069	45.095	0.000
LUT * Soil depth	8.000	0.005	3.537	0.001
Error	84.000	0.002
Total	99.000
Corrected Total	98.000

Analysis of Variance (ANOVA) for available P content

Source	Df	Mean Square	F	Sign
Corrected Model	14.00	31,334.53	2.91	0.00
Intercept	1.00	519,661.95	48.23	0.00
LUT	4.00	86,788.57	8.05	0.00
Soil depth	2.00	23,900.86	2.22	0.12
LUT * Soil depth	8.00	4487.61	0.42	0.91
Error	84.00	10,774.56
Total	99.00
Corrected Total	98.00

Analysis of Variance (ANOVA) for organic carbon stocks

Source	Df	Mean Square	F	Sign.
Corrected Model	14.000	523.735	6.519	0.000
Intercept	1.000	107,411.615	1336.875	0.000
LUT	4.000	833.943	10.379	0.000
Soil depth	2.000	1693.306	21.075	0.000
LUT * Soil depth	8.000	101.607	1.265	0.273
Error	84.000	80.345
Total	99.000
Corrected Total	98.000

Analysis of Variance (ANOVA) for total nitrogen stocks

Source	Df	Mean Square	F	Sign.
Corrected Model	14.000	3.556	6.245	0.000
Intercept	1.000	794.961	1396.023	0.000
LUT	4.000	5.032	8.836	0.000
Soil depth	2.000	12.630	22.179	0.000
LUT * Soil depth	8.000	0.730	1.282	0.264
Error	84.000	0.569
Total	99.000
Corrected Total	98.000

ANOVA soil organic carbon stocks for entire soil profile (0–45 cm)

Source	Df	Mean Square	F
Corrected Model	14.000	29.130	4.557	0.000
Intercept	1.000	6993.372	1093.938	0.000
LUT	4.000	48.713	7.620	0.000
Soil depth	2.000	93.593	14.640	0.000
LUT * Soil depth	8.000	5.003	0.783	0.619
Error	84.000	6.393
Total	99.000
Corrected Total	98.000

Analysis of variance(ANOVA) for total nitrogen stocks for entire soil profile

Source	Df	Mean Square	F
Corrected Model	14.000	4338.965	4.871	0.000
Intercept	1.000	945,944.645	1061.879	0.000
LUT	4.000	7922.220	8.893	0.000
Soil depth	2.000	12,600.119	14.144	0.000
LUT * Soil depth	8.000	729.803	0.819	0.588
Error	84.000	890.821
Total	99.000
Corrected Total	98.000