Land preparation before planting
Since all the
land was previously planted with agricultural crops, 92 percent of the
respondents cleared land, and eight percent
prepared bedding and terraces/platforms before planting (Table 27).
Table 27. Land preparation before planting
Type of land
preparation |
Companies (n =6) |
Individual
planters (n = 21) |
Total (n = 27) |
|||
No. |
% |
No. |
% |
No. |
% |
|
Clearing |
5 |
83 |
20 |
95 |
25 |
92 |
Bedding |
0 |
0 |
1 |
5 |
1 |
4 |
Terraces/platforms |
1 |
17 |
0 |
0 |
1 |
4 |
Total |
6 |
100 |
21 |
100 |
27 |
100 |
Fertilizer application
All respondents
applied fertilizer during and after planting. Common fertilizers applied during
planting were chicken manure, phosphate, NPK and urea (Table 28). After
planting, companies discontinued chicken manure application while the
individual planters continued to apply this type of fertilizer. NPK was the
most common fertilizer used during and after planting by companies and
individual planters. All companies applied NPK only after planting.
Table 28. Types of fertilizer used during and after planting
Type of
fertilizer |
Companies (n = 6) |
Individual
planters (n = 21) |
Total (n = 27) |
During planting |
|||
Chicken manure |
3 |
4 |
7 |
Phosphate |
1 |
5 |
6 |
NPK |
3 |
11 |
14 |
Urea |
0 |
1 |
1 |
After planting |
|||
Chicken manure |
0 |
2 |
2 |
Phosphate |
0 |
3 |
3 |
NPK |
6 |
15 |
21 |
Urea |
0 |
1 |
1 |
Note: One company applied more than one type of fertilizer during planting.
Various reasons were given for choosing a specific fertilizer during and after planting (Table 29). Cost considerations were most important for companies. Of the six companies, four percent indicated that a particular fertilizer was used because of low cost while 17 percent attributed their choice to its availability and another 17 percent to ease of application. Two-thirds of the individual planters applied the fertilizer recommended by RISDA. Other reasons included low cost, availability, ease of application and perceived positive impact.
Table 29. Reasons for choosing the type of fertilizer
Reason |
Companies (n = 6) |
Individual
planters (n = 21) |
Total (n = 27) |
|||
No. |
% |
No. |
% |
No. |
% |
|
Cheap |
4 |
66 |
0 |
0 |
4 |
16 |
Easily available |
1 |
17 |
2 |
11 |
3 |
12 |
Easy to use |
1 |
17 |
1 |
5 |
2 |
8 |
Proposed by RISDA |
0 |
0 |
12 |
63 |
12 |
48 |
Good in terms of
growth |
0 |
0 |
6 |
29 |
6 |
22 |
Total |
6 |
100 |
21 |
100 |
27 |
100 |
In general, the
frequency of fertilizer application is about the same for companies and the
individual planters (Table 30). Except for the first year when companies
applied fertilizer three times (compared to two for individual planters), the
number of fertilizer applications was the same from year 2 onwards. The average
number of fertilizer applications declined to once a year
from year 5 onwards.
Table 30. Average number of fertilizer applications per year
Average number of fertilizing per year |
||
Year |
Companies (n = 6) |
Individual planters (n = 21) |
Year 1 |
3 |
2 |
Year 2 |
2 |
2 |
Year 3 |
2 |
2 |
Year 4 |
2 |
2 |
Year 5 |
1 |
1 |
Year 6 |
1 |
1 |
Year 7 |
- |
1 |
Year 8 |
- |
0 |
Year 9 |
- |
0 |
Weeding
Weeding was done
in various ways (Table 31): over the total area (56 percent), using line
weeding (22 percent), by circle weeding (11 percent) and by chemical
spraying (four percent). Not all of the respondents weeded every
year. The extent of weeding depended on the perception of the
need to do so. In a certain year, no weeding
would be done.
For example, in year 1 of planting, one company and three individual planters
did not weed as weed pressure was low.
Table 31. Types of weeding
Type of
weeding |
Companies (n = 6) |
Individual
planters (n = 21) |
Total (n = 27) |
|||
No. |
% |
No. |
% |
No. |
% |
|
Total land area |
4 |
66 |
11 |
52 |
15 |
56 |
Line weeding |
0 |
0 |
6 |
28 |
6 |
22 |
Circle weeding |
1 |
17 |
2 |
10 |
3 |
11 |
No weeding |
0 |
0 |
2 |
10 |
2 |
7 |
Chemical spraying |
1 |
17 |
0 |
0 |
1 |
4 |
Total |
6 |
100 |
21 |
100 |
27 |
100 |
The average
number of weedings per year generally declined after the third year
(Table 32). Weeding was discontinued from the fifth year onwards.
Table 32. Average number of weedings per year
Average
weeding intensity |
Companies (n = 6) |
Individual
planters (n = 21) |
Total (n = 27) |
Year 1 |
2 |
2 |
2 |
Year 2 |
2 |
2 |
2 |
Year 3 |
2 |
2 |
2 |
Year 4 |
1 |
1 |
1 |
Year 5 |
1 |
1 |
1 |
Year 6 |
0 |
0 |
0 |
Two individual
planters did not weed at all. They perceived that weeding would reduce soil
moisture especially during the dry period and this would increase pest
infestations and diseases. They also felt that weeds retain soil moisture,
which is important for tree growth especially during dry spells. Consequently,
they attribute the good growth performance of their trees to lack of weeding.
Climber cutting
On average, companies cut climbers once a year during the first three years of planting. The individual planters rarely cut climbers.
Survival rate and replanting
In general, the survival
rate of trees was very high (Table 33). It was about 95 percent during the
first three years of planting. Consequently, replanting was not done. There was
no obvious difference in survival rate between mixed and single species
plantations. The survival rate of teak that was inter-cropped with banana was
low. This might be related to waterlogging on clay soils.
Table 33. Average survival rates (%)
Year planted |
Teak +
banana |
Teak only |
Teak + oil
palm |
Teak +
tongkat ali |
Sentang only |
Sentang +
rubber |
Mixed forest
species |
Maesopsis eminii |
Year
1 |
75.0 |
93.3 |
82.0 |
92.5 |
84.0 |
94.7 |
90.0 |
95.0 |
Year
2 |
65.0 |
97.5 |
96.5 |
97.5 |
97.1 |
95.0 |
95.0 |
95.0 |
Year
3 |
- |
98.3 |
97.7 |
98.5 |
97.5 |
91.9 |
97.0 |
90.0 |
Year
4 |
- |
100 |
99.0 |
97.0 |
100 |
97.0 |
97.0 |
- |
Year
5 |
- |
100 |
100 |
97.0 |
100 |
- |
97.0 |
- |
Year
6 |
- |
100 |
100 |
97.0 |
- |
- |
- |
- |
Year
7 |
- |
100 |
100 |
97.0 |
- |
- |
- |
- |
Year
8 |
- |
- |
100 |
97.0 |
- |
- |
- |
- |
Year
9 |
- |
- |
100 |
97.0 |
- |
- |
- |
- |
Height
and diameter increment
Table 34 shows that for
single-species plantations, the average annual height increment was about 1.9 m
(teak), 1.5 m (sentang) and 3.3 m (Maesopsis
eminii). For mixed plantations, it
was 1.7 m (teak and banana), 0.8 m (teak
and oil palm), 0.8 m (teak and tongkat ali), and 1.3 m (sentang and rubber).
This seems to indicate that in single-species plantations trees grew faster
than when they were inter-cropped, although the differences were not very
pronounced for sentang.
Table 34. Average tree height (m)
Year planted |
Teak +
banana |
Teak only |
Teak + oil
palm |
Teak +
tongkat ali |
Sentang only |
Sentang +
rubber |
Mixed forest
species |
Maesopsis eminii |
Year
1 |
2.5 |
2.9 |
2.2 |
2.0 |
1.9 |
2.4 |
n.a. |
n.a. |
Year
2 |
3.3 |
4.7 |
2.7 |
2.5 |
3.0 |
3.6 |
n.a. |
7.6 |
Year
3 |
- |
6.3 |
3.5 |
3.3 |
4.0 |
4.6 |
n.a. |
10.0 |
Year
4 |
- |
8.7 |
4.7 |
4.0 |
5.6 |
5.0 |
n.a. |
- |
Year
5 |
- |
10.8 |
5.7 |
4.5 |
7.5 |
- |
n.a. |
- |
Year
6 |
- |
12.3 |
6.5 |
5.0 |
- |
- |
- |
- |
Year
7 |
- |
13.0 |
7.3 |
5.5 |
- |
- |
- |
- |
Year
8 |
- |
- |
8.0 |
6.0 |
- |
- |
- |
- |
Year
9 |
- |
- |
9.0 |
- |
- |
- |
- |
- |
Average
annual growth |
1.7 (0.8–2.5) |
1.9 (0.7–2.4) |
0.8 (0.5–2.2) |
0.8 (0.5–2) |
1.5 (1–1.9) |
1.3 (0.4–2.4) |
- |
3.3 (3–4.6) |
Figures in parentheses are the range. n.a. = not available.
There were also some differences in the diameter growth trees planted in mono- and mixed cultivation (Table 35). In monocultivation, the average annual dbh increment was 2 cm (teak), 2.4 cm (sentang) and 1.6 cm (Maesopsis eminii). In the case of inter-cropping, the values were 3.3 cm (teak and banana), 1.4 cm (teak and oil palm), 1.2 cm (teak and tongkat ali), and 1.9 cm (sentang and rubber).
Table 35. Average diameter at dbh (cm)
Year planted |
Teak +
banana |
Teak only |
Teak + oil
palm |
Teak +
tongkat ali |
Sentang only |
Sentang +
rubber |
Mixed forest
species |
Maesopsis eminii |
Year 1 |
4.0 |
2.8 |
2.9 |
3.0 |
4.1 |
3.8 |
n.a. |
n.a. |
Year 2 |
6.5 |
4.7 |
4.9 |
3.8 |
6.2 |
5.2 |
n.a. |
13.7 |
Year 3 |
- |
6.6 |
6.4 |
4.5 |
7.9 |
6.9 |
n.a. |
15.3 |
Year 4 |
- |
8.8 |
7.9 |
5.5 |
10.8 |
7.5 |
n.a. |
- |
Year 5 |
- |
10.8 |
9.6 |
6.5 |
12.1 |
- |
n.a. |
- |
Year 6 |
- |
12.3 |
11.8 |
7.5 |
- |
- |
- |
- |
Year 7 |
- |
14.0 |
12.7 |
8.5 |
- |
- |
- |
- |
Year 8 |
- |
- |
15.0 |
9.5 |
- |
- |
- |
- |
Year 9 |
- |
- |
17.0 |
- |
- |
- |
- |
- |
Average annual growth |
3.3 (2.5–4.0) |
2 (1.5–2.8) |
1.4 (0.9–2.9) |
1.2 (0.8–3.0) |
2.4 (1.3–4.1) |
1.9 (0.6–3.8) |
- |
- |
n.a. = not available.