| Summary: | 碩士 === 國立屏東科技大學 === 環境工程與科學系 === 90 === Large amounts of agricultural wastes are produced in Taiwan, however, the crop residues with 700 million tons may be treated by composting. For the reuse of agricultural wastes to reduce their contamination, popular agricultural wastes were applied to prepare liquid fertilizers by controlling composting parameters and to assess the liquid fertilizers on the effects of soil fertility and crop yield in this study. The raw materials for preparing the liquid fertilizers are bean residue, rice bran, wine and sugarcane processing by-products, and leaf residue of cabbage. Two preparing methods are conducted, one is preparing liquid fertilizer transformed by solid composting, and the treatments are divided into without microorganism (S-1), with comprehensive microorganism (S-2), and with comprehensive microorganism and Bacillus thuringiensis (S-3). The other is liquid composting, and the treatments are divided into without microorganism (L-1), with maturely solid compost (L-2), and with comprehensive microorganism (L-3). All the liquid fertilizers were applied in a Typic Hapludorent planted with Chinese cabbage (Brassica Chinensis L.) in the pots.
Results indicate that C/N ratios decreased to 10 and pH values tended to 7.0-7.5 in all treatments by solid composting for 40 days. But in all treatments by liquid composting for 40 days, C/N ratios decreased to less than 6 and pH values were higher than those by solid composting. The wave number of aliphatic carbons in FTIR decreased with composting time, but the 1560cm-1 zone with aromatic carbons increased with the maturation of liquid fertilizer. All treatments include 18 essential amino acids, but phenylalanine is the dominant one. The addition of liquid fertilizer significantly (p<0.05) increased N, P, and K contents of the soil in the pot experiment. The yields of Chinese cabbage in liquid fertilizer treatments were also significantly higher than those of blank. However, there is no difference in nutrient composition among liquid fertilizer treatments. Therefore, The efficiency of the liquid fertilizer transformed by solid composting on soil fertility and crop yield is higher than that of liquid compositing.
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