Planting of trees can be done by hand or machine. The choice between the two depends on a number of factors, including the number of trees to be planted, roughness and/or steepness of the terrain and, in some cases, the availability of a planting machine.
In all methods of planting, these guidelines should be observed: (1) seedlings should be planted slightly deeper (never shallower) than the depth in the nursery bed, (2) long roots should be pruned to about 8 inches in length (or not longer than the depth of the planting hole) using a sharp knife or clippers (never torn); (3) the tree should be planted with the main root straight down- never twisted, doubled up or sharply bent in the planting hole; (4) soil should be pressed firmly around roots to hold the tree firmly in place and (5) seedlings should be planted in a vertical position (see Fig. 24).
Efforts should be made during planting to ensure that trees within rows are lined up and spacing between rows is fairly uniform. This facilitates movement of equipment between rows without damaging trees and promotes uniform applications of herbicides, fertilizers, insecticides, fungicides, etc. It can be done in a number of ways. Stakes placed at intervals in rows can be used, particularly when trees are to be hand planted. Marking rows with lime or a slit in the soil made with a disk or planting machine is also helpful. Bars mounted on the tractor can be used when machine planting. The tip of the bar or a rope dangling from it is kept even with the previously planted row, regulating distance between rows. When laying out areas for planting, rows of trees should be as long as possible (depending on size and configuration of area, terrain, etc.) to reduce delays associated with turning equipment, etc.
Hand planting methods fall into two general groups- hole and slit methods. Techniques used with these methods are illustrated in Fig. 24. Hole planting can be done with a mattock, hoe or shovel. It is particularly adapted to rough, rocky land, trees with large, spreading root systems, finer textured (clay) soils and for interplanting in previously planted areas. Slit planting is much faster than hole planting and is especially adapted for tap-rooted species and use on coarse (sandy) and medium textured loam and silt loam soils. Hand planting rates generally vary from 200 to 500 trees per man day, although faster rates may be possible under optimum conditions. Average time requirements for hand planting are listed in Table 4.
Fig. 24:Planting methods. Correct and incorrect depths. L. to R., correct: at same depth or 1/2 deeper than seedling grew in nursery; incorrect: too deep and roots bent; incorrect: too shallow and roots exposed.
Dibble planting. Clockwise from upper left, 1) insert the dibble as shown and pull toward planter; 2) remove dibble and place seedling at correct depth, 3) insert dibble 2 inches toward planter from seedling; 4) pull handle of dibble toward planter, firming soil at bottom of roots; 5) push handle of dibble forward from planter, firming soil at top of roots and 6) firm soil around seedling with feet.
Mattock planting. Clockwise from upper left, 1) insert mattock-lift handle and pull; 2) place seedling along straight side at correct depth, 3) fill in and pack soil to bottom of roots; 4) finish filling in soil and firm with heel and 5) firm around seedling with feet.
If a tree planting machine is available, planting can be done more quickly and efficiently than hand planting (see Fig. 25). The planting machine is either attached to a tractor by a standard three-point hitch or is pulled behind a tractor on wheels attached to the planting machine. Although designs vary considerably, several components are common to all mechanical planters-a rolling courter or cutting blade that cuts through the ground surface, a trenching plate or plow that opens a furrow, a pair of packing wheels that firm the soil after planting, some type of carrier (usually a tray) for planting stock and a seat for the person doing the planting. Some planters accommodate two people. With most machines, the roots of the seedlings are placed by hand in the hollow created by the trencher and are held until the packing wheels compress the soil around the roots. Some machines have clips arranged on a rotating arm or chain. Seedlings are placed in the clips, and the trees are moved into position in the furrow and held by the clips until the packing wheels close the trench. Such machines do not require the planter to bend down each time a tree is planted. Planting depth and spacing between trees can be controlled closely with this type of machine. Those without clips can be equipped with a spacing wheel that makes a sound when a tree is to be planted.
|Fig. 25: Two types of tree planting machines. Upper photo, planter where seedlings and placed by hand in the planting slit. Lower photo, planter mechanically places seedlings in the planting slit by use of mechanical "fingers" attached to a rotating chain. Parts of the machines include seedling carrier, seat, packing wheels, courter, trencher or plow, spacing wheel and contour adjustment.|
Topography is one of the major factors limiting use of planting machines. On sloping ground, trees are usually planted along the contour. Slopes up to 20 to 25 percent can be planted safely, depending on tractor type and the particular planting machine. Machine planting may also be difficult on stony and fine textured soils because it is difficult for the machine to open a suitable trench and pack the soil firmly around the roots (see section "Chemical Control of Woody Plants"). A crew of two (one on the tractor and one on the planter) can plant 2,000 to 5,000 or more seedlings per day, depending on soils, terrain, planting stock, etc. Table 4 gives typical time requirements for equipment and labor for machine planting.
Regardless of the planting method, care must be taken to keep seedlings moist while planting. When trees are taken from bundles, cold storage or heel-in beds, they should be placed in containers filled with wet sphagnum moss, water or moist soil. The former is preferred. When hand planting, seedlings should not be removed from the container until after the planting hole is prepared. While using a machine, it may be necessary to take several seedlings from the planting box at one time because of the speed of the operation. However, every effort must be made to keep roots moist.