Palawan肥料使用和薄虫产量的评价
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- 爱思唯尔——哈佛大学
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- MLA
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摘要
Palawan在1993 - 94年的乳鱼产量低,平均只有595公斤/公顷,而且在50个农场的35个农场的35岁的范围内达到100-700公斤/千年。只有七场农场的产量在1,000至1,800公斤/千年之间。在更深的池塘里,产量较高,池塘的杨氏度是高产的主要约束。农场的乳鱼价格从P25到P55和平均p42。百草鱼的价格平均低于有机肥料(鸡粪)的价格和6倍超过无机肥料的价格。来自麦田的收入增加了10-95%,平均为农民总收入的53%。一年的一个作物循环是50个农场中的28个的做法;20个农场有两种作物,每年有两个农场3-4家农村。作物周期为14个农场3-4个月,29个农场5-6个月,7个农场7-9个月。作物循环开始于排水和干燥池塘,涂抹肥料以种植天然食物。 Most of the farms were supplied by tidal water and water exchange in the ponds was done every spring tide in 33 farms. The other farms changed water once a month, once or twice in a crop cycle, or once a year. Application rates of organic fertilizers were mostly less than 1 ton/ha-yr and averaged 515 kg/hayr, but three farms used as much as 1,250 kg/ha-yr, and one farm used 3,000 kg/ha-yr. Half as much inorganic fertilizers were used; the average for the 50 farms was only 211 kg/ha-yr, but one farm used as much as 1,350 kg/ha-yr. The fertilizers encouraged natural food to grow in the ponds. Two of the farms grew mostly plankton, 15 grew the benthic mat lablab, and 33 grew the green filamentous algae lumut. None of the farms used commercial feeds. Stocking rates varied widely among the farms, ranged from 1,000 to 60,000 fry or fingerlings per hectare per year and averaged 8,000/ ha-yr. Two-thirds of the farms stocked less than 7,000/ha-yr, but eight farms stocked fry or fingerlings at much higher rates of 13,000–60,000/ ha-yr. An input use variation model showed that milkfish yield was a function of the ratios of prices of milkfish to prices of organic and inorganic fertilizers; pond water depth and salinity; milkfish income as percent of total income; family size; membership in aquaculture association; and contacts with government‘s extension services and information dissemination system. The surveyed farms ranged from 3 to 40 years old, with 92% under 20 years; they had been in operation 1–23 years, 76% of them for less than eight years. Of the 50 farms in the survey, only nine were private (titled) lands, 34 were covered by fishpond lease agreements (FLA issued by the Bureau of Fisheries and Aquatic Resources), and the others had only survey documents or no papers at all. Farm sizes ranged 0.8–50 ha (average 12.5 ha), and 52% of them were smaller than 6 ha. The private farms were small, only 1–7 ha except one that was 25 ha. The FLA farms were much larger, and 23 of them were 5–50 ha. Large parts of the large farms were not operational, and 90% of the farms used effective areas of less than 7 ha. The low lease fees for FLAs evidently did not encourage farm development to increase yields. The farms had mostly shallow ponds 25–100 cm deep (average 68 cm).
建议引用
Dumada-UG,E. B.,&塞维利亚·罗尔,R。(2007)。Palawan肥料使用和薄鱼产量的评价。在T. U.Bagarinao(ED。),渔业部门计划的研究产出(Vol.2。关于渔业和水产养殖的报告,第138-149页)。奎松市菲律宾:农业科学局,农业部。