CHEMICAL-COMPOSITION OF MUNICIPAL LEAF WASTE AND HAND-COLLECTED URBANLEAF-LITTER

Municipal leaf waste delivered to New Jersey farms was sampled to eval uate its chemical composition and suitability for land application. Fr eshly fallen leaf litter samples were also collected and analyzed from seven different urban landscape tree species. Municipal leaf waste da ta from 100 samples in this study was summarized using frequency distr ibutions to characterize its variability in composition. The chemical composition of municipal leaf waste was found to be quite variable. Th e minimum-maximum and median values were as follows: (g kg(-1)) C, 363 to 516, 480; N, 6.6 to 26.2, 9.4; P, 0.2 to 2.9, 1.0; K, 0.9 to 8.8, 3.6; Ca 1.3 to 30.4, 17.3; Mg, 0.2 to 4.6, 2.4; S, 0.1 to 2.1, 1.1; (m g kg(-1)) B, 7 to 72, 38; Fe, 46 to 9800, 733; Al, 58 to 10554, 602; M n, 19 to 1845, 406; Zn, 22 to 392, 67; Na, 36 to 325, 90; Cl, 68 to 39 95, 1083; Cu, 2.8 to 31.5, 8.1; Co, 0.9 to 10.9, 2.7; Cd, 0.1 to 6.8, 1.3; Pb, 3 to 400, 18; Ni, 1 to 58, 5; Cr, 0.9 to 35.1, 6.6; ha, 4.2 t o 142.0, 49.4. Although municipal leaf waste contains significant amou nts of valuable plant nutrients, the high C/N ratio (range: 26.8-71.8; median: 48.5) suggests that heavy applications are likely to cause im mobilization of available soil N. Concentrations of Fe, Al, Pb, and Cd were generally higher and more variable in municipal leaf waste than in hand-collected leaf litter. This suggests that contamination with u rban soil during collection contributes to elevated Pb and Cd concentr ations in municipal leaf waste. Given careful attention to N-fertilize r practice, municipal leaf waste is a suitable material for applicatio n to farm land.