The use of composted oil palm wastes in the oil palm nursery as an organic component of growing medium for oil palm seedlings seems promising in sustainable oil palm seedling production. This study was conducted to investigate the effects of six oil palm waste compost rates (0, 20, 40, 60, 80, and 100%) on the growth performance of oil palm seedling and nutrient uptake in the prenursery stage (0–3 months). The addition of oil palm compost reduced the soil bulk density (1.32 to 0.53 g cm−3) and increased soil pH (4.7 to 5.1) of growth media. Oil palm waste compost treatment produced positive growth performance up to 70%. A regression analysis indicated in 72% of compost and topsoil mixture as a polybag growth medium was optimum in producing best growth performance of oil palm seedling in the prenursery stage. Foliar analysis implied highest nutrients uptake (N, P, K, Mg, Ca, Fe, Zn, and Cu) for seedlings grown in 60 to 100% compost media.
Oil palm (
Topsoil has been conventionally used as the growing medium for oil palm seedling during nursery stage. However, it is not practical for long term due to the increasing nutrient demand of oil palm seedling and depletion of fertile soils. The production of high quality seedlings is dependent on good growing media. The physicochemical and biological properties of a growing medium will affect plant growth and directly influence roots growth. Furthermore, the planting medium must be porous and well drained to permit free roots penetration, secure anchorage, and have sufficient nutrients to support crop growth [
Amendment materials such as dry effluent and coir dust [
Earlier reports of oil palm waste application on oil palm seedling were mainly on raw EFB during the main nursery stage. In this study, a different type of oil palm waste, the oil palm mesocarp, was utilized and focused on the prenursery stage (rather than the main nursery stage) to produce high quality seedlings. Thus, the aims of this study were to investigate the effects of oil palm waste compost which consisted of pressed oil palm fruit mesocarp and palm oil mill effluent (POME) as a component of polybag medium on growth performance of oil palm seedlings and nutrients uptake during the prenursery stage (0–3 months) in the double stage nursery system.
This study was conducted under shelter in Universiti Putra Malaysia (2°59′59N, 101°42′25E) with air temperature of 24–33°C. Oil palm waste of pressed oil palm fruit mesocarp and POME were obtained from Golden Hope Plantation Berhad and composted in Universiti Putra Malaysia. Oil palm seeds, GH500, a cross-breed product between Elite Deli Dura and second generation of Pesifera, BM119, were used in this study. Polybag media were prepared by mixing compost with the Serdang series topsoil (Ultisol, Tipik Lutualemkuts) at the ratio of 0 (C0), 20 (C20), 40 (C40), 60 (C60), 80 (C80), and 100% (C100). The characteristics of the topsoil and oil palm waste compost were similar to C0 (topsoil only without compost) and C100 (solely compost), respectively. The experiment was carried out in a randomized complete block design (RCBD) with six replications.
Planting distance between each of the poly bags in the block was 30 cm and was 50 cm between each of the blocks. One germinated oil palm seed (GH500) was sown in each polybag of 15 cm × 23 cm with equal volume of media. The seedlings were watered twice a day and weeding was done manually. A compound fertilizer, N-P-K-Mg (14 : 7 : 9 : 2.5), was applied weekly (1.0 g per polybag) from week 7 to week 12 after sowing.
Plant height was recorded during the 12 weeks of prenursery period at weeks 1, 2, 4, 6, 8, 10, and 12. All seedlings were left to grow until the 12th week (Figure
Each medium treatment was analyzed for bulk density, pH (1 : 4, soil : water), and macro- and micronutrient contents as shown in Table
Selected physical and chemical characteristics of growing media.
Treatments | Bulk density | pH | C : N | C | N | P | K | Ca | Mg | Mn | Zn | Cu |
---|---|---|---|---|---|---|---|---|---|---|---|---|
(g cm−3) | (H2O) | Ratio | (%) | mg kg−1 | ||||||||
C0 | 1.32 |
4.68 |
23.89 |
2.75 |
0.12 |
0.24 |
0.56 |
0.11 |
0.09 |
18.25 |
22.25 |
11.75 |
C20 | 1.24 |
4.85 |
26.05 |
5.72 |
0.22 |
0.31 |
0.56 |
0.15 |
0.13 |
22.00 |
29.25 |
13.00 |
C40 | 1.11 |
5.08 |
28.23 |
10.65 |
0.38 |
0.35 |
0.57 |
0.18 |
0.15 |
24.25 |
25.50 |
12.00 |
C60 | 0.95 |
5.13 |
31.33 |
18.47 |
0.59 |
0.49 |
0.53 |
0.22 |
0.22 |
19.50 |
23.75 |
9.75 |
C80 | 0.75 |
5.15 |
29.78 |
28.32 |
0.95 |
0.83 |
0.56 |
0.26 |
0.28 |
21.75 |
32.25 |
13.75 |
C100 | 0.56 |
5.10 |
61.51 |
73.19 |
1.19 |
1.24 |
0.55 |
0.26 |
0.35 |
21.50 |
46.25 |
23.00 |
Note: means with the same letter within row are not significantly different at
Analysis of variance (ANOVA) was performed for all parameters with the statistical analysis system, SAS version 9.2 (SAS Institute, Inc., Cary, NC, USA). Differences between treatments were analysed using LSD at
The pH value of growing media significantly increased from 4.68 in C0 and peaked at 5.15 in C80. Thus, the pH value for mixture of compost and topsoil of C60 and C80 was significantly higher than pure compost (C100). Mixing the compost with topsoil reduced the bulk density by up to 43% from the original topsoil (C0) and there was no significant difference between C80 and C100 (Table
PCA of the chemical properties of growth media was generated (Table
Factor pattern, eigenvalues, and percentages of the variance explained by each factor, obtained from the first PCA performed on the physicochemical properties of growing media.
PC 1 | PC 2 | PC 3 | |
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Soil pH |
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Bulk density (g cm−3) |
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C : N ratio |
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C% |
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N% |
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P% |
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K% |
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Ca% |
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Mg% |
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Cu (mg/kg) |
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Zn (mg/kg) |
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Mn (mg/kg) |
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Na (mg/kg) |
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Eigenvalue |
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% variance |
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(a) Scree plot of eigenvalue. (b) Principal components analysis (PCA) of initial physicochemical properties of growing media (–⋅– broken stick. C0, C20, C40, C60, C60, C80, and C100 represent 0, 20, 40, 60, 80, and 100% of compost, resp.).
The nutrients uptake of oil palm seedlings is shown in Table
Effect of compost addition in growing media on nutrients uptake by oil palm seedlings.
Treatments | N | P | K | Ca | Mg | Cu | Zn | Mn | Fe |
---|---|---|---|---|---|---|---|---|---|
mg plant−1 | |||||||||
C0 | 12.60 |
8.39 |
11.43 |
3.00 |
2.83 |
25.86 |
53.35 |
110.12 |
509.79 |
C20 | 16.80 |
11.78 |
13.52 |
3.09 |
4.45 |
28.42 |
49.67 |
110.63 |
373.19 |
C40 | 19.30 |
14.53 |
15.66 |
3.42 |
4.28 |
28.10 |
57.63 |
121.83 |
436.94 |
C60 | 29.66 |
25.72 |
19.70 |
5.12 |
6.44 |
44.48 |
86.73 |
142.56 |
739.40 |
C80 | 33.68 |
24.21 |
24.01 |
5.71 |
6.53 |
52.50 |
92.00 |
135.35 |
675.38 |
C100 | 32.48 |
27.76 |
21.38 |
4.89 |
6.44 |
43.91 |
85.15 |
105.74 |
752.78 |
Note: means with the same letter within row are not significantly different at
Based on the regression studies, the shoot dry weight, root dry weight, plant height, and SPAD reading of oil palm seedlings were related to the amount of compost added (Figure
Effect of compost application rates on (a) shoot dry weight, (b) root dry weight, (c) plant height, and (d) chlorophyll meter readings (SPAD value) of oil palm seedlings. Note:
Relationship between SPAD value and plant nitrogen (N) uptake. Note:
Growth of seedlings at the 12th week in prenursery stage.
Addition of oil palm waste compost decreased the bulk density of topsoil-compost growing medium. This could be attributed to the dilution effect [
Adding compost also improved the chemical properties of the growing medium as shown by various studies, which reported the ability of compost to reduce soil acidity [
Furthermore, compost could also supply the seedlings with additional N, P, Ca, Mg, and Zn, functioning as a source of nutrients beside applied fertilizers. Another plausible mechanism was compost retaining the nutrients in the growing media by surface adsorption and increased nutrient recovery [
The oil palm seedling growth and physiology improved with the application of compost. This was majorly attributed to the alteration of physicochemical properties of the growing medium. Multiple regression study showed that root and shoot growth and macronutrients uptake were highly significantly related to the pH of the growing media (Table
Relationship between shoot and root dry weight, nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), and magnesium (Mg) uptake and soil pH as affected by compost addition in growing media.
Interaction between soil pH and | Equation |
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Shoot dry weight, g−1 |
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0.86 |
Root dry weight, g−1 |
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0.78 |
N uptake, mg plant−1 |
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0.84 |
P uptake, mg plant−1 |
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0.84 |
K uptake, mg plant−1 |
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0.85 |
Ca uptake, mg plant−1 |
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0.85 |
Mg uptake, mg plant−1 |
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0.88 |
Note:
Furthermore, the seedling root growth was clearly associated with the bulk density, reflected by the increasing pore space and soil aeration. Addition of composted agricultural waste had been reported to significantly improve root growth [
Correlation matrix between dry shoot and root, nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), and magnesium (Mg) in soil and plant nutrient uptake as affected by compost addition in growing media.
Parameter | Root | Shoot | N | P | K | Ca | Mg | N | P | K | Ca | Mg | |
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Dry weight (g) | Uptake (mg plant−1) | Soil before treatment (%) | |||||||||||
Root | Dry weight (g) | 1.00 | 0.57 |
0.81 |
0.68 |
0.84 |
0.78 |
0.40 |
0.68 |
0.58 |
−0.22 |
0.79 |
0.63 |
Shoot | 0.80 |
0.84 |
0.74 |
0.86 |
0.67 |
0.70 |
0.61 |
−0.27 |
0.73 |
0.67 |
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N | Uptake (mg plant−1) | 0.87 |
0.92 |
0.88 |
0.55 |
0.83 |
0.75 |
−0.31 |
0.86 |
0.84 |
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P | 0.82 |
0.82 |
0.57 |
0.84 |
0.77 |
−0.38 |
0.83 |
0.77 |
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K | 0.88 |
0.55 |
0.82 |
0.72 |
−0.17 |
0.86 |
0.80 |
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Ca | 0.61 |
0.74 |
0.64 |
−0.27 |
0.77 |
0.71 |
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Mg | 0.50 |
0.44 |
−0.31 |
0.54 |
0.45 |
Notes:
Apart from promoting nutrient uptake, compost addition also influenced nutrient availability and retention in the growing medium. The surface of organic matter like compost is rich in negative functionalities such as phenolic, carboxylic, carbonyl, and alcohol which serve as exchange sites that ultimately increased the CEC of growth media [
However, growth of oil palm seedling is negatively affected by compost application, solely due to the high C : N ratio, causing N immobilization. However, C : N value would decrease gradually when microorganisms start breaking down the compost and slowly release plant available nutrients to the soil throughout the seedlings growth period. Similar results have been reported by [
Prenursery polybag medium amended with oil palm waste compost up to 70% increased oil palm seedling growth. Meanwhile, 72% of the compost mixed with topsoil could produce the best planting material with respect to the high DMW production, oil palm seedlings growth, and development as well as greater nutrient uptake. Further study is required to investigate whether the amount of chemical fertilizer employed during nursery stage could be reduced, thus cutting operational cost by making use of oil palm waste compost as polybag growth medium.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors would like to thank Universiti Putra Malaysia for providing the facilities and Golden Hope Plantation Bhd., Banting, for the oil palm waste that was used to produce the compost.