Study on the Testing Conditions of Spectroscopic Analysis for Maturity Index of Composts

• Main Authors: Yung-Chang Lin, 林永章
• Other Authors: Yi-Hong Lin
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/96305507324035627482

碩士 === 國立屏東科技大學 === 機械工程系所 === 98 === The organic agriculture is one of important tasks in global recently, and the application of organic fertilizer is increasing. However, the mature degree of organic fertilizer is involved in the supplement of nutrients for crops and the improvement of soil properties. In the past, the mature index of compost was evaluated by instruments in the laboratory, it wasted much time and fund. This study was conducted to evaluate the feasibility of spectroscropic condition on the determination of compost maturity. Fourier Transform Infrared spectroscopy (FTIR) and 13C Nuclear- Magnetic- Resonance (13C NMR) were used to estimate five compost. At first, soybean, pig, lemon, chicken and cattle manure were adjusted with sawdust for moisture (60~65%) and carbon and nitrogen ratio (C/N,35~40), they were overturned two times at first week, and one time per week after first week. The nutritions,organic matter, humic acid, C/N ratio, the germination percentage of vegetable seeds and FTIR spectrum were analyzed after 0,2,4,6,8 weeks. And 13C NMR was analyzed after compost maturity. The results showed that C/N ratio of five composts were all below 20 after 8 weeks. The germination percentages of vegetable seeds were all higher than 85%, it showed that they were mature after 8 weeks. Organic matter and total nitrogen of five composts were increasing and than dercreasing with compost time. The contents of phosphate, potassium, calcium, magnesium, iron, manganese, copper, zinc and humic acid were increasing with composting time for five treatments. The content of humic acid was highest(5.0%) in the cattle manure after mature, and was lowest(about 1.3%) in the soybean manure after 6 weeks. FTIR analysis showed that aromatic groups were all found in the five composts, and the surface of compost contained carboxylic group, hydroxylic group and amino group. The decreases of peak between 2930cm-1 and 2820cm-1, i.e. aliphatic area, and the decrease of 1385cm-1, i.e. amino acid. On the other hand, the production of peak at 1650cm-1, i.e. aromatic area, and at 1385 cm-1, i.e. carboxylic group, phenolic group could be identified the mature index of five compost. The 13C NMR analysis showed that the mature compost was consisted with aliphatic and aromatic group, they contained the groups of CO bond, carboxylic and ester bonds, aldehydes and ketones. There are some different spectrum absorption at five composts, however, their degree of absorption showed apparently difference. These results may be the conditions for design of spectroscopic machine for determination of mature composts.