Response of Sorghum (Sorghum bicolor L.) to Residual Phosphate in Soybean-Sorghum and Maize-Sorghum Crop Rotation Schemes on Two Contrasting Nigerian Alfisols

Table 1

Precropping chemical and particle size analysis of the soils used in the study.

Properties	Soil A (strongly acidic Alfisol)	Soil B (slightly acidic Alfisol)
pH (1 : 1 soil/water ratio)	5.3	6.7
Bray-1-P (mg/kg)	5	9
Total N (g/kg)	2.0	2.0
Organic matter (g/kg)	27.1	26.5
Exchangeable base (cmol/kg)
K	0.2	0.3
Ca	1.6	1.8
Mg	0.7	0.7
Na	0.1	0.1
Exchangeable acidity (cmol/kg)	0.4	0.6
Exchangeable micronutrients (cmol/kg)
Fe	0.3	0.2
Mn	0.3	1.3
Cu	0.04	0.01
Zn	0.01	0.01
Particle size distribution (gkg^−1)
Sand	628.0	871.0
Silt	150.0	40.0
Clay	222.0	89.0
Texture	Sandy clay loam	Loamy sand