Soil nutrient management is necessary to maintain the constant productivity of nursery systems as well as good quality soil. This study investigated the effects of organic manure and chemical fertilizer treatments on growth performance and soil and tissue chemical properties. Two-year-old yellow poplar (Liriodendron tulipifera L.) seedlings were treated with an organic manure (1000 g/m²; mixture of poultry manure, cattle manure, swine manure, and sawdust), nitrogen–phosphorus–potassium (NPK) chemical fertilizer (urea, 30 g/m²; fused superphosphate, 70 g/m²; potassium chloride, 15 g/m²), and organic manure plus NPK chemical fertilizer. Control seedlings were left untreated. Growth of seedlings, soil properties, and nutrient concentrations were measured to compare the treatments. Organic manure significantly increased the soil pH and the concentrations of nitrogen, available phosphorus, exchangeable potassium, calcium, and magnesium. In contrast, the NPK chemical fertilizer decreased the soil pH and exchangeable calcium concentration, did not affect the soil concentrations of nitrogen and magnesium, and increased the concentrations of available phosphorus and exchangeable potassium. Fertilization treatments increased the seedling height and root collar diameter by 21% and 29%, respectively, and the mean dry weight of the stems and leaves by 72% and 123%, respectively; but a synergistic effect of the organic manure and NPK fertilizer was not observed. Compared to the effects of the fertilization treatments on the soil properties, the effects on nutrient concentrations in the leaves, stems, and roots were relatively small. These findings indicate that organic manure derived from livestock byproducts and sawdust can be utilized in seedling production systems.

Coring methods cannot reveal the distribution of roots with depth in rocky soil, and fine roots are typically sampled without regard to the location of trees. We used quantitative soil pits to describe rooting patterns with soil depth and distance to trees in northern hardwood stands. We sited three 0.5 m² quantitative soil pits in each of three young (19–27 years) and three older (56–69 years) stands developed after clear-cutting. Live roots were divided into diameter classes delimited at 0.5, 1, 2, 5, 10, 20, and 100 mm; dead roots were not distinguished by size. Mean total live-root biomass was 2900 ± 500 g·m^–2 in older stands and 1500 ± 400 g·m^–2 in young stands. The root mass in the 2–20 mm class was 2.7 times greater in the older stands (p = 0.03); fine-root (<2 mm) biomass was 1.5 times greater (p = 0.12), suggesting that fine-root biomass continues to increase past the age of canopy closure in this forest type. Root biomass density declined with soil depth, with the finest roots (<0.5 mm) declining most steeply; roots were found at low densities well into the C horizon. We analyzed root biomass density as a function of the influence of nearby trees (represented as the sum of basal area divided by the distance from the pit) and found that fine as well as coarse roots reflected this influence. In systems where this is the case, root measurements should be made with attention to patterns of tree distribution.