Publication Date
1997
Description
The objective of this study was to determine the horizontal and vertical variations in soil penetration resistance (PR) observed at tree-scale in silvopastoral plots that were grazed by sheep with and without trees. Sycamore trees (Acer pseudoplatanus L) were planted in the spring of 1988 at 10 m x 10 m spacing (100 stems/ha) at Glensaugh NE of Scotland on plots replicated over three blocks in Randomized Complete Block design on a predominantly rye grass (Lolium perenne L) pasture. Included in the design were pasture plots without trees (Control). The experiment is grazed by sheep yearly from April to October. Soil PR was measured in Mega Pascals (MPa) around two randomly selected trees in each plot in 8 directions of the compass - N, NE, E, SE, S, SW, W and NW at 1 m intervals starting at 0.5 m from the tree base to mid point of the separation distance (4.5 m) between the trees. The soil PR data were measured at 3.5 cm soil depth intervals at points around the tree up to depth limit of 21.0 cm. This gave six depth intervals of d1 (3.5), d2 (7.0), d3 (10.5), d4 (14.0), d5 (17.5) and d6 (21.0). In the Control plots, soil PR was measured as in the Sycamore plots around two hypothetical tree positions chosen randomly in each plot. The soil PR was found to decrease significantly within the horizontal distance of 4.5 m from the tree and depth for up to d3 (10.5 cm) only in the grazed Sycamore plots. Soil penetrometer resistance was found to increase significantly within the vertical distance of 0-14 cm of the soil around the tree in grazed Sycamore and Control plots. Beyond this soil depth, soil PR was no longer significant in these treatments.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Trees for Shelter: The Implications in Agroforestry System
The objective of this study was to determine the horizontal and vertical variations in soil penetration resistance (PR) observed at tree-scale in silvopastoral plots that were grazed by sheep with and without trees. Sycamore trees (Acer pseudoplatanus L) were planted in the spring of 1988 at 10 m x 10 m spacing (100 stems/ha) at Glensaugh NE of Scotland on plots replicated over three blocks in Randomized Complete Block design on a predominantly rye grass (Lolium perenne L) pasture. Included in the design were pasture plots without trees (Control). The experiment is grazed by sheep yearly from April to October. Soil PR was measured in Mega Pascals (MPa) around two randomly selected trees in each plot in 8 directions of the compass - N, NE, E, SE, S, SW, W and NW at 1 m intervals starting at 0.5 m from the tree base to mid point of the separation distance (4.5 m) between the trees. The soil PR data were measured at 3.5 cm soil depth intervals at points around the tree up to depth limit of 21.0 cm. This gave six depth intervals of d1 (3.5), d2 (7.0), d3 (10.5), d4 (14.0), d5 (17.5) and d6 (21.0). In the Control plots, soil PR was measured as in the Sycamore plots around two hypothetical tree positions chosen randomly in each plot. The soil PR was found to decrease significantly within the horizontal distance of 4.5 m from the tree and depth for up to d3 (10.5 cm) only in the grazed Sycamore plots. Soil penetrometer resistance was found to increase significantly within the vertical distance of 0-14 cm of the soil around the tree in grazed Sycamore and Control plots. Beyond this soil depth, soil PR was no longer significant in these treatments.
