نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه رازی، کرمانشاه، ایران
2 گروه علوم و مهندسی خاک، دانشکده کشاورزی،دانشگا رازی، کرمانشاه، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Humic acid is an organic compound that can improve the physical, chemical and biological properties of soil. In addition, it plays an important role in increasing plant growth and yield. This composition can be extracted from various sources that are rich in organic materials such as composts, coal, humus materials and soil. In order to know the spectral and structural characteristics of this compound, humic acid was extracted from different organic sources in 2021. The amounts of carbon, oxygen, hydrogen and nitrogen elements in the extracted humic acids were determined by elemental analyzer, functional groups by FTIR and the spectrophotometric absorption ratios of E3/E5 and E4/E6 were determined by spectrophotometer in Department of Soil Science and Engineering laboratory, Razi University, Kermanshah. The lowest H/C ratio in the extracted humic acids was observed from municipal waste compost (1.05) and vermicompost (1.09), the highest O/C ratio was in humic acid extracted from municipal waste compost (0.70) and vermicompost (0.59), and the lowest C/N ratio was in humic acid of chicken manure (11.84). According to the results of FTIR analysis, the strongest absorption bands were observed at 3400 cm-1, 2900-3000 cm-1, 1600- 1700 cm-1 and 1000-1100 cm-1. The highest ratio of E3/E5 was found in humic acid extracted from chicken manure (12.81) and sheep manure (10.61) and the lowest amount was observed in municipal waste compost (2.00). The highest ratio of E4/E6 was obtained in humic acid extracted from chicken manure (7.31) and the lowest amount of E4/E6 was observed in humic acid obtained from municipal waste compost (4.70).
کلیدواژهها [English]
EXTENDED ABSTRACT
Humic acid is an organic compound that can improve the physical, chemical and biological properties of soil. In addition, it plays an important role in increasing plant growth and yield. This composition can be extracted from various sources that are rich in organic materials such as composts, coal, humus materials and soil.
In order to know the spectral and structural characteristics of this compound, humic acid was extracted from different organic sources in the Department of Soil Science and Engineering of Razi University, Kermanshah, Iran in 2021.
Two organic sources of cow manure compost and vermicompost were the result of the composting process in previous researches in the Faculty of Agriculture. Municipal waste compost was prepared from Kermanshah city waste recycling and compost production factory. Sheep and chicken manure were also obtained from the farm of the Faculty of Agriculture. The amounts of carbon, oxygen, hydrogen and nitrogen elements in the extracted humic acids were determined by elemental analyzer, functional groups by FTIR and the spectrophotometric absorption ratios of E3/E5 and E4/E6 were determined by spectrophotometer.
The amount of carbon was between 47.61 and 57.67 %, hydrogen between 4.19 and 7.16 %, nitrogen between 3.30 and 5.68 %, and oxygen between 30.18 and 44.90 %. The lowest H/C ratio in the extracted humic acids was observed from municipal waste compost (1.05) and vermicompost (1.09), the highest O/C ratio was in humic acid extracted from municipal waste compost (0.70) and vermicompost (0.59), and the lowest C/N ratio was in humic acid of chicken manure (11.84). According to the results of FTIR analysis, the strongest absorption bands were observed at 3400 cm-1, 2900-3000 cm-1, 1600- 1700 cm-1 and 1000-1100 cm-1. The results of this part showed that the extracted humic acids had aromatic rings in addition to aliphatic compounds and included COOH, COO-, OH, C=O and C-O functional groups in their structure. The results of analysis of variance showed that there was a significant difference between the absorbance ratios of E3/E5 and E4/E6 in humic acids extracted from different sources at 1% level. The highest ratio of E3/E5 was found in humic acid extracted from chicken manure (12.81) and sheep manure (10.61) and the lowest amount was observed in municipal waste compost (2.00). The highest ratio of E4/E6 was obtained in humic acid extracted from chicken manure (7.31) and the lowest amount of E4/E6 was observed in humic acid obtained from municipal waste compost (4.70).
In general, humic acid extracted from municipal waste compost had higher degree of polymerization, aromatic compounds, degree of condensation and humification than the other organic sources, and humic acid obtained from chicken manure had the lowest degree of humification and decomposition.
Keywords: Elemental analysis E3/E5, E4/E6, FTIR, Humic acid