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The forest regeneration phase in Sweden commonly involves mechanical soil preparation followed by the planting of Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) Karst) seedlings. The prepared soil offers planting positions with different properties, including reduced damage by pine weevils (Hylobius abietis L.). Nitrogen fertilization can be applied at the time of planting to aid establishment of the seedlings. In this study, we compared the effects of different planting positions, organic nitrogen fertilization, and different seedling sizes on the early survival and growth of Scots pine and Norway spruce seedlings. The main planting positions were capped mound, hinge, and mineral soil. Seedlings planted close to organic material were categorized as being in "low-quality positions", since proximity to organic material increases pine weevil attraction. Higher mortality rates related to pine weevil damage were recorded for the seedlings planted in the low-quality positions, regardless of seedling size or N fertilization. Pine weevil attack rates increased with increasing seedling size. Growth was, in general, lowest in the mineral soil positions. The effect of organic N fertilization on growth was positive for the spruce regardless of the planting position or seedling size, while it depended on the planting position and seedling size for the pine, indicating that the effects of organic N fertilization depend on the seedling species, seedling size, and planting position. [ABSTRACT FROM AUTHOR]

The forest regeneration phase in Sweden commonly involves mechanical soil preparation followed by the planting of Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) Karst) seedlings. The prepared soil offers planting positions with different properties, including reduced damage by pine weevils (Hylobius abietis L.). Nitrogen fertilization can be applied at the time of planting to aid establishment of the seedlings. In this study, we compared the effects of different planting positions, organic nitrogen fertilization, and different seedling sizes on the early survival and growth of Scots pine and Norway spruce seedlings. The main planting positions were capped mound, hinge, and mineral soil. Seedlings planted close to organic material were categorized as being in “low-quality positions”, since proximity to organic material increases pine weevil attraction. Higher mortality rates related to pine weevil damage were recorded for the seedlings planted in the low-quality positions, regardless of seedling size or N fertilization. Pine weevil attack rates increased with increasing seedling size. Growth was, in general, lowest in the mineral soil positions. The effect of organic N fertilization on growth was positive for the spruce regardless of the planting position or seedling size, while it depended on the planting position and seedling size for the pine, indicating that the effects of organic N fertilization depend on the seedling species, seedling size, and planting position.

Nitrous oxide (N2O) emissions from pastures can vary significantly depending on soil and environmental conditions, nitrogen (N) input, as well as the plant’s ability to take up the N. We tested the hypothesis that legume-based N sources are characterized by significantly lower emission factors than mineral N based dairy systems. Therefore, this study monitored N2O emissions for a minimum of 100 days and up to two growing seasons across a gradient of plant species diversity. Emissions were measured from both grazed pastures and a controlled application of urine and dung using the static chamber method. About 90% of the simulated experiments’ accumulated N2O emissions occurred during the first 60–75 days. The average accumulated N2O emissions were 0.11, 0.87, 0.99, and 0.21 kg ha−1 for control, dung, urine patches, and grazed pastures, respectively. The N uptake efficiency at the excreta patch scale was about 70% for both dung and urine. The highest N2O-N emission factor was less than half compared with the IPCC default (0.3 vs. 0.77), suggesting an overestimation of N2O-N emissions from organically managed pastures in temperate climates. Plant diversity showed no significant effect on N2O emission. However, functional groups were significant (p < 0.05). We concluded that legume-containing pasture systems without a fertilizer addition generally appear capable of utilizing nitrogen inputs from excreta patches efficiently, resulting in low N2O emissions.