Organic Amendments and Earthworm Addition Improve Properties of Nonacidic Mine Tailings

Figure 2

Mean NO₃⁻-N concentrations in amended mine tailings; (a) treatments that included 10% biosolids addition; (b) treatments that included 20% biosolids addition. Error bars indicate (±1 SD; 𝑛=3). See Table 2 for explanation of treatment codes.

(a)

(b)