Figure 3. Effects of mulching with composted yard waste and recycled wood pallets on
(a) total extractable soil nitrogen, (b) percent of total soil nitrogen immobilized by soil
microbes, (c) rate of nitrogen mineralization, and (d) plant available nitrogen (sum of
NH4, NO3, and dissolved organic nitrogen pools) in early October 1998 and late April
1999. Data are expressed as mean ± standard error. Means within a year with the same
letter are not significantly different (protected LSD test, P < 0.05).