Effect of biosolids application on site productivity.

<p>Increase in 300 Index of trees treated with standard and high rates of biosolids versus untreated trees. The bars represent the least significant difference (LSD) values calculated for each age. Differences between the standard and high treatments, and between either of these and the control (zero line), which are greater than the LSD, are statistically significant (p = 0.05). The arrows show when biosolids treatments were applied.