Figure 5

Growth status of ground and root of maize under different amounts of HA and PHA (a) and dry weight of maize with different amounts of HA and PHA (b). CK Hoagland's nutrient solution without humic acids, HA10, HA20, and HA50 Hoagland's nutrient solution with humic acids of 10, 20, and 50 mg C/L, PHA10, PHA20, and PHA50 Hoagland's nutrient solution with PHA of 10, 20, and 50 mg C/L. Bars represent mean ± SD (n = 5). Means with no letter in common are significantly different (P < 0.05), as indicated by the Tukey’s HSD test.