Mobility and fractionation of copper in sandy soils

Figures & data

Table 1. Selected properties of the soils used in this study.

			Depth	Sand	Silt	Clay	Organic C	pH	Total
									Fe	Mn	Al
Soil Series	Classification	Horizon	(cm)	– – – – -% – – – –			(g kg^−1)	(1:1 H2O)	– – – mg kg^−1 – – –
Wabasso	Sandy, siliceous, hyperthermic Alfic Haploquods	Ap	0–25	93.8	4.8	1.4	19	6.46	102.2	69.3	72.3
		E	25–60	98.2	1.7	0.1	1	5.54	2.9	0.3	4.3
		Bh	60–85	88.6	9.3	2.1	47	4.75	196.5	0.8	13.6
Riviera	Loamy, siliceous, hyperthermic Arenic Glossaqualf	Ap	0–30	95.8	2.8	1.4	16	6.12	154.6	19.9	121.8
Candler	Hyperthermic, uncoated Typic Quartzipsamment	Ap	0–20	94.4	4.1	1.5	7	6.86	456.3	85.5	370.6

Figure 1. Cumulative amount of Cu recovered in eight pore volumes of leachate from five soil horizon samples expressed as percentage of Cu applied (50 kg Cu ha⁻¹). The vertical line on the top of each histogram represents the standard error of the mean.

Figure 2. Elution curves of Cu for five soil horizon samples amended with 50 kg Cu ha⁻¹ and leached continuously with eight pore volumes of water.

Figure 3. Distribution of soil Cu in soil columns following the addition of 50 kg Cu ha⁻¹ and leaching with eight pore volumes of water. The error bar at each data point represents the standard error of the mean.

Figure 4. Proportion of total Cu in various forms in three sandy soils with addition of 50 kg Cu ha⁻¹ and leached with eight pore volumes of water.

Table 2. Correlation coefficients between specific fractions of copper and some soil parameters.

				Total
Copper Forms	pH	Clay Content	Organic Carbon	Fe	Mn	Al
Exchangeable	−-0.37	−-0.87	−-0.45	−-0.61	−-0.55	−-0.47
Organically bound	−-0.46	0.90*	0.95**	0.16	−-0.20	−-0.20
Precipitated	0.99**	−-0.04	−-0.61	0.52	0.91*	0.80
Residual	0.77	0.52	−-0.11	0.86*	0.85*	0.90*

*, ** Significant at the P < 0.05 and 0.01 level, respectively.