EVALUATION OF FOREST TREE PLANTING MACHINE EFFECTIVENESS

Soil preparation method - mounding (with varying depth of the pit and the mound height) - may be the solution for establishing new forests when the soil water regime is unfavourable, since the pit serves as a reservoir for water during rainy periods and can retain water for the dry season. Thus, seedlings planted on mounds may obtain water through the soil capillary system when needed. During the last decades extreme weather conditions have occurred more often. And as there is a labour shortage for simple forest management tasks and increased hourly labour cost mechanized planting on mounds could be a promising solution to advance tree planting practices in Latvia. The aim of this study was to compare the productivity, quality and cost of mechanized planting and manual planting in Latvian conditions, where planting density of 2-2.5 thousand seedlings per ha is used. The M-planter was selected for the mechanized establishment of forest sites on mounded soils. During field trials, when 2000 trees per ha were planted, the productivity of the M-planter was 11.2 h ha on drained peat soils, 11.6 h per ha on drained mineral soils and 14.1 h per ha on wet mineral soils. Average mechanized planting time per 1 ha was 11.9 h, while making mounds and manual planting together took 11.2 h per ha. The cost of mechanized planting experiments in Latvian conditions, depending on the number of seedlings planted and planting conditions varied between 450 and 550 EUR per ha. Tree establishment success did not differ between the sites with mechanized or manually planted seedling, but depended more on the local site conditions.