Silva Fennica

Fig. 1. A typical planting stick (left), consisting of a wooden rod with an iron planting tip, and iron wire with bolts indicating precise planting spots. Photo on the right shows a worker in the middle stretching a wire line to prepare the next row, a worker on the left waiting for her turn, and a worker on the right doing actual planting and soil compaction work.

Table 1. Description of work elements of the two planting methods.
Method	Work phases	Work elements	Description
Planting stick	Preparation	Moving	Begins when the worker starts walking towards a new location and ends when s/he reaches it
	Preparation	Aligning	Begins when the worker starts looking at colleagues to set the marking chains perpendicular to each other (visually) and ends when workers have finished putting marking sticks in the ground
	Planting	Walking	Begins when the worker starts walking to a marked location and ends when s/he reaches it
		Preparing	Begins when the worker puts a planting stick in the soil and ends when s/he moves to the next spot
		Planting	Begins when the worker takes a seedling from his/her bag and ends when s/he is back in the standing position
		Tamping	Begins when the worker starts to compact the soil by foot and ends when s/he is ready to move on
Planting tube	Preparation	Measuring	Begins when the worker starts to measure the correct distance for the next row from the previous row and ends when the location is defined
		Walking	Begins when the worker starts walking towards the new location of a marking stick and ends when s/he reaches it
		Locating	Begins when the worker puts a marking stick in the ground and ends when it is checked and corrected, to ensure that it is parallel with others
		Moving	Begins when the worker starts to walk ahead of a marking stick to the next location and ends when s/he reaches it
	Planting	Walking	Begins when the worker starts walking to a planting spot and ends when s/he reaches the spot
		Preparing	Begins when the worker presses the planting tube to the ground and ends when the jaws are opened
		Planting	Begins when the worker moves his/her hand to the basket and ends when a seedling is dropped out of the tube
		Pulling up	Begins when the worker starts to pull up the tube and ends when the jaws are closed
		Tamping	Begins when the worker compacts soil by foot and ends when s/he is ready to move on
		Navigating	Begins when the worker sets the tube next to the planted seedling and ends when s/he lifts up the tip of the dimension stick from the next planting spot

Fig. 2. Alignment layout applied in the planting stick method by using two wires (20 m). The three meters indicates space between the rows and the two meters indicates the space between planting spots.

Fig. 3. Photos showing a planting tube with a measuring rod used to indicate the correct distance between the seedlings (left panel), and a planter using marker sticks for correct alignment (right panel).

Table 2. Cost factors used for both planting methods.
	Cost factor	Planting stick	Planting tube	Unit
Fixed cost	Purchase price of the tool	8.00	141.30	€
	Number of tools	10	1
	Purchase price of the iron wires per seedling basket	10.70	48.00	€
	Total purchase price	90.70	189.30	€
	Service life	2	5	a
	Salvage value	15	15	%
	Total salvage value	13.60	28.40	€
	Interest on capital	6	6	%
Variable cost	Hourly wage	1.00	1.00	€ h^–1
	Number of workers	10	1	Person per method
	Duration of a working day	8	8	Hours day^–1
	Number of working days	120	120	Days year^–1

Table 3. Productivity of the planting stick method, performed by a group of workers, and average time for each work element.
Planting stick	Work element	s seedling^–1
	Moving	0.59
	Aligning	0.78
Preparation	Subtotal	1.37
	Walking	4.39
	Preparing	4.82
	Planting	3.12
	Tamping	2.90
Planting	Subtotal	15.23
	Total	16.60

Table 4. Productivity of the planting tube method, performed by one person. The preparation time was calculated for a planting row, which consisted of 48 seedlings.
Planting tube	Work element	s seedling^–1
	Measuring	0.29
	Walking	0.08
	Locating	0.09
	Moving	0.59
Preparation	Subtotal	1.05
	Walking	3.01
	Preparing	3.24
	Planting	2.4
	Pulling up	1.37
	Tamping	7.03
	Navigating	2.90
Planting	Subtotal	19.95
	Total	21.00

Table 5. Fixed, variable, hourly, and unit costs of the two planting methods, based on the productivity study and cost calculation.
	Planting stick	Planting tube
Fixed costs, € h^–1	0.0446	0.0413
Variable costs, € h^–1	9.99	1.00
Hourly cost, € h^–1	10.04	1.04
Unit cost, € seedling^–1	0.0463	0.0061

Table 6. Results of REBA evaluation of work-related stress incurred using the planting stick method. Values in the ‘additional’ row include waiting time. The letter n in the first row indicates the respective number of observations.
Work phase	Work element	Negligible		Low		Medium		High		Very High		Total
Work phase	Work element	%	n	%	n	%	n	%	n	%	n	%	n
Preparation	Moving			9.5	6	14.3	9					23.8	15
	Aligning	27.0	17	39.7	25	6.3	4	3.2	2			76.2	48
	Total	27.0	17	49.2	31	20.6	13	3.2	2			100	63
Planting	Walking			23.1	24	4.8	5					27.9	29
	Preparing			1.0	1	16.3	17	3.8	4			21.1	22
	Planting					3.8	4	20.2	21			24.0	25
	Tamping			5.8	6	5.8	13					18.3	19
	Additional			8.7	9							8.7	9
	Total			38.5	40	37.5	39	24.0	25			100	104

Table 7. Results of REBA evaluation of work-related stress for the planting tube method. Values in the ‘additional’ row includes addition of seedlings to a container.
Work phase	Work element	Negligible		Low		Medium		High		Very High		Total
Work phase	Work element	%	n	%	n	%	n	%	n	%	n	%	n
Preparation	Measuring			15.2	7	19.6	9	4.4	2			39.2	18
	Walking	8.7	4	2.2	1							10.8	5
	Locating	8.7	4	8.7	4							17.4	8
	Moving	32.5	15									32.6	15
	Total	49.9	23	26.1	12	19.6	9	4.4	2			100	46
Planting	Navigating	1.4	2	9.4	13	0.7	1					11.5	16
	Walking	2.2	3	10.1	14	0.7	1					13.0	18
	Preparing	2.2	3	10.1	14	9.4	13					21.5	30
	Planting	3.6	5	6.5	9	7.2	10					17.3	24
	Pulling up
	Tamping	3.6	5	15.8	22	13.7	19					33.1	46
	Additional	2.9	4			0.7	1					3.6	5
	Total	15.8	22	51.8	72	32.4	45					100	139