| Summary: | 碩士 === 朝陽科技大學 === 建築系建築及都市設計碩博士班 === 104 === In 2013, according to the statistics of the Environmental Protection Administration of the Executive Yuan, kitchen wastes account for 35.04% of the total amount of wastes, while recyclable kitchen wastes account merely 10.67%. Every year, there are approximately 2/3, that means 1.8 million tonnes, of kitchen waste not recycled and are treated as ordinary wastes cause certain impacts to the environment. Kitchen wastes contain the nutrients and organic matters required for the growth of the plants. After compost formation, they become organic fertilizers which can shrink down in volume. If we can handle it by ourselves, we can effectively reduce the volume of wastes for treatment as well as the environmental impacts. They may also be applied on the soil as they may increase soil fertility and stability, and promote plant growth.
This study aims to explore and test the differences of the efficiency of homemade solid fertilizers and commercially available organic fertilizer using cabbages. The efficiency of the organic fertilizers is usually assessed by soil fertility indicators after its application on the ground. These include the nutritional factors (nitrogen, phosphorus pentoxide, potassium hydroxide, calcium oxide and magnesium oxide) and chemical factors (pH, conductance and organic matters). In terms of the growth of the plants, nitrogen, phosphorus pentoxide, potassium are the leading element. However, the Agricultural Research and Extension Station of the Executive Yuan (2004) pointed out that there is no correlation between nitrogen and the amount of fertilizer in the soil fertility testing, so it shall not be included in our research. The homemade organic fertilizer provided for this experiment used the kitchen wastes of the lunch boxes from Chaoyang University of Technology as the raw materials. Single-slot food waste decomposer CF-100a was used for the manufacturing. Taipei Organic Fertilizer No. 1 was used as the commercial organic fertilizer. The experiment was divided into homemade fertilizer and commercial fertilizer in single, doubled and quadruple amounts of fertilizer respectively. The control group is one without fertilizer, so there were a total of seven groups. The time of the experiment consisted from April 24th, 2015, to May 28th, 2015, a total of 35 days. Soil testing were carried out during key days for the growth of the cabbage, such as the day of germination, seedling thinning, fix planting and top dressing (the 3rd, 7th, 10th, 15th, 20th, 25th, 30th and 35th day of the sowing). The samples of the soil and the fertilizers were sent to Taoyuan District Agriculture Research and Extension Station (Items of examination: PH, conductance, organic matters, phosphorus pentoxide and potassium hydroxide); the height of the plants were measured daily, while the follow-up used Pearson correlation between soil fertility factors.
The results of the experiment show: (1) after the harvest on the 35th day, the plants were placed in the order of the height. The best was the homemade doubled fertilizer group followed by commercial single fertilizer group, homemade quadrupled fertilizer group, homemade single fertilizer group, no fertilizer group, commercial doubled fertilizer group and commercial quadrupled fertilizer group; (2) at the early stage of the planting (the first 15 days), the growth of the control group without fertilizer was above all the other groups. But at the late stage (the last 15 days), the growth of the cabbages had significant changes having homemade doubled fertilized group and commercial single fertilizer group as the most notable ones; (3) excessive fertilization with collateral fertilizer damages occurred at homemade tripled fertilizer group, commercial doubled fertilizer group and commercial quadrupled fertilizer group affecting the growth of the plant. Among them, the homemade fertilizer group may increase the soil conductance due to the high level of soluble salt content causing salt damages. Fertilizer damages were caused at the commercial fertilizer groups due to the excessive level of potassium concentration; (4) relevant statistics show that there are correlations between the soil fertility factors. The PH value has negative correlation with the organic matters, the conductance, phosphorus pentoxide and potassium hydroxide, while the organic matters have positive correlation with conductance, phosphorus pentoxide and potassium hydroxide.
This research shows that in terms of homemade fertilizer, doubled amount is the best in efficiency. However, during the manufacturing of organic fertilizer with kitchen wastes, there is a higher concentration of soluble salt; an excessive application would cause salt damage. In terms of commercial organic fertilizer, single amount is the best in efficiency. Overdose would release excessive nutrients causing fertilizer damage. This study proves that the application of organic fertilizer manufactured with kitchen wastes have positive efficiency towards the soil and can effectively reduce the amount of wastes, so it is highly recommended for further promotion.
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