Research Article

Compost and Crude Humic Substances Produced from Selected Wastes and Their Effects on Zea mays L. Nutrient Uptake and Growth

Table 8

Total and exchangeable cations (mg kg−1) in crude humins from different composts.

CationsRice strawRice huskSawdustEFB

K (%)2.33b (±0.06)1.79c (±0.06)1.95c (±0.02)2.84a (±0.08)
Ca (%)1.46a (±0.16)1.03ab (±0.11)0.76b (±0.06)1.44a (±0.09)
Mg (%)0.79a (±0.08)0.53bc (±0.05)0.33c (±0.03)0.73ab (±0.06)
Na (%)0.18a (±0.00)0.14b (±0.01)0.17a (±0.01)0.18a (±0.01)
Fe (%)0.21a (±0.01)0.07c (±0.00)0.05c (±0.00)0.13b (±0.01)
Cu (mg kg−1)39.70c (±2.23)29.43d (±2.23)86.53b (±1.21)97.50a (±2.82)
Mn (mg kg−1)226.60a (±16.93)232.83a (±15.87)46.57c (±6.42)148.50b (±6.63)
Zn (mg kg−1)164.43b (±5.27)81.33d (±2.65)117.60c (±1.21)184.93a (±3.63)
Exchangeable K (cmol kg−1)38.25a (±1.16)28.95b (±0.44)25.79b (±1.83)37.57a (±1.01)
Exchangeable Ca (cmol kg−1)12.58b (±0.46)12.60b (±0.05)12.45b (±1.13)21.50a (±0.53)
Exchangeable Mg (cmol kg−1)6.96b (±0.16)6.81b (±0.09)9.50a (±0.58)10.04a (±0.20)
Exchangeable Na (cmol kg−1)4.11a (±0.09)3.10b (±0.04)3.14b (±0.21)3.55b (±0.08)

Different alphabets within a row indicate significant difference between means using Tukey’s test at .
( ) values in parenthesis represent standard error of the mean.