Table 5.

Effect of planting pit modifications and of open soil surface on leaf mineral content (percent on dry matter).^{^z}

	Nitrogen	Phosphorus	Potassium	Calcium	Magnesium
Substrate
Topsoil + compost 25%	1.48 a	0.18 a	0.91 a	1.354 a	0.15 a
Topsoil + compost 50%	1.65 a	0.19 a	0.90 a	1.67 a	0.15 a
Topsoil + compost 75%	1.35 a	0.13 a	0.42 a	1.80 a	0.13 a
Topsoil (control)	1.65 a	0.16 a	0.44 a	2.20 a	0.19 a
P	0.488	0.693	0.239	0.433	0.500
Size of nonpaved surface
1 m² (10.8 ft²) + metal grate	1.20 b	0.12 b	0.52 a	1.40 b	0.14 a
6.25 m² (67.5ft²) + pine bark and groundcover	1.85 a	0.19 a	0.71 a	2.20 a	0.18 a
P	0.027	0.019	0.290	0.014	0.056
Interactions substrate × size
P	0.702	0.000	0.002	0.008	0.000

↵^zData represent the average of 2 years’ analyses. Values differ significantly when followed by different letters at P ≤ 0.05 (least significant difference test).