Integrated Crop-Livestock Management Effects on Soil Quality Dynamics in a Semiarid Region: A Typology of Soil Change Over Time

Table 3

Mean values (±1 standard deviation) for soil properties in 2002, 2005, and 2008.

Variable	2002	2005	2008
Soil bulk density (Mg m^−3)	1.05 ± 0.08	1.09 ± 0.10	1.12 ± 0.11
Electrical conductivity (dS m^−1)	0.24 ± 0.04	0.30 ±0.06	0.41 ± 0.10
Soil pH (−log[H^+])	6.12 ± 0.38	6.23 ± 0.38	6.32 ± 0.55
Soil nitrate (mg kg^−1)	4 ± 3	5 ± 4	8 ± 9
Soil ammonium (mg kg^−1)	2 ± 1	2 ± 0	5 ± 3
Available phosphorus (mg kg^−1)	8 ± 3	5 ± 4	10 ± 6
Potentially mineralizable N (mg kg^−1)	74 ± 22	86 ± 24	86 ± 34
Soil organic carbon (g kg^−1)	30.1 ± 3.9	26.6 ± 3.6	29.6 ± 5.7
Total nitrogen (g kg^−1)	2.7 ± 0.3	2.3 ± 0.3	2.7 ± 0.5
C : N ratio	11.2 ± 0.4	11.4 ± 0.4	11.1 ± 0.4