PART III
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| Sago Trees (Improve The Best Claim) |
The experiment was conducted at the National Timber and Forest Product sago palm plantation located in Tebing Tinggi Island, Riau Province, Indonesia (1_300N, 103_400E; Jong 2001). The mean annual maximum and minimum air temperatures in the 1996–2000 period, which were recorded at the nearest meteorological station, were 31.9 and 23.3_C, respectively. Annual precipitation was 1,700 mm with the maximum rainfall in December (222 mm) and minimum in July (79 mm). The plantation was initialized in 1996 on deep peat (Histosols) consisting of complex woody materials (100% peat). Tropical swamp forest that covered the plantation area was cleared ca 35 years ago, and thereafter the area was secondary forest. The map of the plantation is shown in Fig. 1. The southwestern border of the plantation is approximately 2.4 km from the coast. The plantation area is divided into 20 phases. One phase consists of 20 blocks, and each block has a land area of 0.5 km2 Fig. 1 Map of sago palm plantation in Tebing Tinggi, Indonesia.
(0.5 9 1 km). Each block is surrounded by roads (5 m width) and facilitated with canals (5 m width). Since 1996, two phases with smaller code numbers have been established per year. Conservation belts (100 m width) of the secondary forest are maintained at two-block intervals (2 km) in the east–west direction, which also face the roads and canals. Major plant species in the secondary forests included Cratoxylon arborescens, Callophyllum inophyllum, Shorea spp., Palaquium burckii, Eugenia spp., Tristania spp., Gonystylus bancanus, and Tetrameristra glabra. Plant density was 156 plants ha-1 (8 9 8 m) in Phase (P) 1 Block (B) 10 and 100 plants ha-1 (10 9 10 m) in the other blocks. Dolomite, urea,
rock phosphate, and KCl were applied at the rates of 30–46.8, 5–7.8, 5–7.8, and 5–7.8 kg ha-1 year-1, respectively, in the first year, and then were gradually increased to 400–624, 80–125, 40–62, and 40– 62 kg ha-1 year-1 for 4-year-old sago palms. CuSO4, ZnSO4, and borate were also applied at the rates of 5–7.8, 5–7.8, and 2–3.1 kg ha-1 year-1 irrespective of palm age (Jong 2001). Fertilizer was applied three times a year. Dolomite was topdressed around a palm so as to draw a circle with a 10 cm width and 1 m radius, and other chemicals in granule
form were introduced via four holes (10 cm depth) made at evenly spaced points on the dolomite circle. The ranges in the application rate of each chemical were derived from the difference in plant density. This manner of fertilization was expected to increase the efficiency of absorption by plants and reduce the leaching to canal. Because some of fertilizer remained in the application spot at next application, fertilizer components may be dispersed throughout a year. Collection of water samples Water samples were collected in triplicate from drainage canals along the sago palm cultivationblocks in December 2002, July 2003, and January, July, and November 2004. November, December, and January are rainy season and July is dry season, although we have not met a shower within 2 days before each sampling. Sampling was conducted in all or some blocks including P1B10 (transplantation of sago palm suckers was conducted in 1997), P3B3 and P3B8 (transplantation in 1998), P4B13 and P4B18 (in 1999), P7B4 (in 2000), and P8B19 (in 2001) at each time (Fig. 1). Total period of sago palm growth (13–15 years in peatland) is divided into three stages of rosette, trunk formation, and ripening. All the plants in this plantation were in the rosette stage throughout the research period. Canal water along the secondary forests adjacent to P3B3 and P7B4 was also collected on the same days except for December 2002. Groundwater samples (triplicates) were collected from holes made at 1 m distance from sago palm plant in P3B3, P7B4, and P8B19 two or three times during canal water sampling days. pH of water samples was measured in the field with a pH meter (D-24, HORIBA, Japan). The water samples brought back to the laboratory were filtrated successively through a glass fiber filter (GB-140, pore size 0.40 lm, ADVANTEC, Japan) and a hydrophilic polyvinylidene fluoride membrane (DURAPORE, pore size 0.45 lm, Millipore, USA). The filters were washed in ultra-pure water before use.
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| Sago pearl |
rock phosphate, and KCl were applied at the rates of 30–46.8, 5–7.8, 5–7.8, and 5–7.8 kg ha-1 year-1, respectively, in the first year, and then were gradually increased to 400–624, 80–125, 40–62, and 40– 62 kg ha-1 year-1 for 4-year-old sago palms. CuSO4, ZnSO4, and borate were also applied at the rates of 5–7.8, 5–7.8, and 2–3.1 kg ha-1 year-1 irrespective of palm age (Jong 2001). Fertilizer was applied three times a year. Dolomite was topdressed around a palm so as to draw a circle with a 10 cm width and 1 m radius, and other chemicals in granule
form were introduced via four holes (10 cm depth) made at evenly spaced points on the dolomite circle. The ranges in the application rate of each chemical were derived from the difference in plant density. This manner of fertilization was expected to increase the efficiency of absorption by plants and reduce the leaching to canal. Because some of fertilizer remained in the application spot at next application, fertilizer components may be dispersed throughout a year. Collection of water samples Water samples were collected in triplicate from drainage canals along the sago palm cultivationblocks in December 2002, July 2003, and January, July, and November 2004. November, December, and January are rainy season and July is dry season, although we have not met a shower within 2 days before each sampling. Sampling was conducted in all or some blocks including P1B10 (transplantation of sago palm suckers was conducted in 1997), P3B3 and P3B8 (transplantation in 1998), P4B13 and P4B18 (in 1999), P7B4 (in 2000), and P8B19 (in 2001) at each time (Fig. 1). Total period of sago palm growth (13–15 years in peatland) is divided into three stages of rosette, trunk formation, and ripening. All the plants in this plantation were in the rosette stage throughout the research period. Canal water along the secondary forests adjacent to P3B3 and P7B4 was also collected on the same days except for December 2002. Groundwater samples (triplicates) were collected from holes made at 1 m distance from sago palm plant in P3B3, P7B4, and P8B19 two or three times during canal water sampling days. pH of water samples was measured in the field with a pH meter (D-24, HORIBA, Japan). The water samples brought back to the laboratory were filtrated successively through a glass fiber filter (GB-140, pore size 0.40 lm, ADVANTEC, Japan) and a hydrophilic polyvinylidene fluoride membrane (DURAPORE, pore size 0.45 lm, Millipore, USA). The filters were washed in ultra-pure water before use.
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