|Special Public Works Programmes - SPWP - Planting Trees - An Illustrated Technical Guide and Training Manual (ILO - UNDP, 1993, 190 p.)|
|4. Planting techniques|
Hoe an area of about 1 square metre around the planting holes. The area should be cleared of all vegetation to eliminate competition for nutrients and water. Dig the planting holes. Holes are required for all containerized plants and for big bare-rooted seedlings. The digging can be done at the same time as planting or some weeks in advance. If holes are dug before the rainy season, labour demand will not interfere with the agricultural season and the actual planting work will be faster. Even when the holes are dug in advance, the plantation worker should bring a hoe to be able to make the holes deeper or to adjust them.
For containerized forest trees the holes should be about 20-40 centimetres in diameter and slightly deeper than the length of the container. For fruit trees the hole should be larger (up to 60 x 60 x 60 cm). The harsher the site, the deeper the holes should be.
For bare-rooted seedlings make sure that the hole is deep enough to allow the taproot to hang down vertically without bending its tip.
Pile the soil on the sides of the hole without scattering it too much. Loosen, if necessary with a pickaxe, the bottom of the hole to make it easier for the plant roots to penetrate the soil.
On favourable sites small bare-rooted seedlings and cuttings may also be planted by just making a slot with a planting hoe (see 5.1).
Digging the holes
Hole for containerized seedling
Hole for bare-rooted seedling
Bigger hole for fruit trees
Tools required for digging
Normal agricultural tools are often not suitable for forestry work. Agricultural hoes, for example, have a wide, straight-edged blade and are heavy. They are therefore difficult to use on most tree planting sites. Suitable tools include the following:
An oval-blade planting hoe is the best planting tool for general purposes The oval blade penetrates the soil more easily than a blade with a straight edge. For containerized seedlings a hoe with a narrow blade can be used; for bare-rooted seedlings a hoe with a wider blade is preferable.
An open-angle hoe has an angle of 100-120° between the blade and the handle. The open angle makes it easier to plant bare-rooted seedlings straight, thus increasing productivity.
The "grubbing mattock" and the "planting mattock" have sturdy narrow blades with straight edges. They should be used if the planting site is stony and difficult.
A pickaxe which has one pointed and one narrow blade edge and a shovel can be used in hard soil when digging deep, big holes. The soil can be loosened with the pickaxe and removed with the shovel.
A wooden dibble or an iron bar can be used when planting cuttings. If loose soil is not available all over the site, extra soil has to carried for filling the holes. Dibbles or bars should only be used in sandy soil, which is not likely to become compacted.
Tools should be adapted to body sizes and for work in particular soils or terrains. The length of the handle should be adapted to the length of the worker. A hoe with a long handle is generally more efficient since it will allow work to be done in an upright standing position. When planting on a steep slope, it is preferable to use a short handed hoe to get a good work posture. Women and elderly workers should have lighter tools than fit male adults. The handle should provide a good grip, and an oval handle is preferable to a round one.
The edges of the planting hoes must be kept sharp with a file, to maintain them in good working condition. The handle should have an oval shape so that it does not twist in the hand. It should have a raised grip to prevent the hands from sliding off. Always keep the handle tightly fastened to the head.
Tools required for digging
Open angle hoe
Straight back planting hoe
Oval blade planting hoe