Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

Figure 9

Treatments (C1: soil alone, C2: soil + complete fertilization, CHS1: soil + complete fertilization + 20 g rice straw compost + 2 g sawdust ash, CHS2: soil + complete fertilization + 40 g rice straw compost + 4 g sawdust ash, and CHS3: soil + complete fertilization + 60 g rice straw compost + 6 g sawdust ash) effect on selected soil exchangeable cations (K⁺, Ca²⁺, Mg²⁺, Na⁺, Cu²⁺, Zn²⁺, Fe²⁺, and Mn²⁺) content at 90 days after seeding. Different alphabets indicate significant difference between means using Tukey’s test at . The error bars are the ± standard error of quadruplicates.