Pyramidal indentations as a microsite preparation for direct seeding of Pinus sylvestris L.

Four field experiments are described in which Scots pine (Pinus sylvestris L) seed was sown in indentations made by pyramidal tools of different form (square base = 4 cm; angles from 44 to 90°; depths from 1 to 5 cm). The indentations were made in the ridges and furrows of a conventional harrow track. Overall, the best treatment was to make shallow indentations (tools: 90°‐1 or 2 cm; 67°‐1 or 2 cm; 44°‐1 cm deep) in ridges of the harrow track. In three experiments these indentations gave at least twofold seedling emergence compared with the control in ridges (seeds sown on soil surface). Soil texture in combination with precipitation affected the emergence results of the different indentation treatments. Indentations in ridges made by tools with a depth of 3 cm or even more gave good results if the soil was stable. For operational purposes the wear‐resistant form “90°‐1 or 2 cm” should be advantageous. The loss of seedlings, as measured up to the end of the third growing period, was significantly more rapid in furrows than in ridges.