HUMUS-SOIL MINERAL INTERFACE IN ORCHARD AND FARM SOILS: NANOSCALE APPROACH
| dc.contributor.author | GURJIT SINGH | |
| dc.date.accessioned | 2017-02-21T06:52:15Z | |
| dc.date.available | 2017-02-21T06:52:15Z | |
| dc.date.issued | 2012 | |
| dc.description.abstract | Clay-Humus complexes are pivotal for understanding long-term carbon retention in soils and founding protocols for nutrients, water and tillage management. Very little attempts were made to decipher the complexes formed under cultivation. Therefore, the study was undertaken for looking at bonding that different clay-minerals made with humus, imaging and deciphering interfaces of clay–humus complexes, and their association with land-use. For this, clays were extracted from surface soils of mango orchard (S1), guava orchard (S2) and ricewheat cultivated field (S3) of Bahadurgarh (30°21 45 N; 76°28 03 E; 255 m) in Punjab, India. Clays were untreated, organic matter (OM) was removed, CaCO3 was removed, and both OM and CaCO3 were removed. They were analyzed by chemical means, by Infra-Red Spectroscopy (IR), and by Scanning Electron Microscopy and Energy Dispersive Spectroscopy. IR spectroscopy identified dioctahedral and trioctahedral illites, and vermiculite, kaolinite, Al-chlorite, and montmorillonite in clays. Humic acids, amides, quinine, ketones and polysaccharides, and fulvic acids were identified in OM. S1 had phenol, and CH2 and CH3 groups, while S2 had aliphatic humic and fulvic acids, and aldehyde of humic acids, and carboxyl and ketonic groups in fulvic acid, and alkenes. The ratio of Oxydizable OC to clay-humus OC was: S1 (0.049) < S3 (0.054) < S2 (0.060). Micrographs portrayed uniform spread, irregular spread, and scattered lump of humus on various clayminerals. The humus from guava field had higher C content (15.60 by atom %) than humus from mango (12.1 by atom %), and cultivated fields (9.78 by atom %). Strong bond between clay minerals and humus deforms OH of clay minerals, and causes COO- anti-symmetric stretching in humus. Presence of phenol compounds in humus on clay surfaces tender resistance of these complexes to microbial degradation, and could be a crucial factor for N management in soils. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810001923 | |
| dc.keywords | Clay humus complexes, clays, electron microscopy, inorganic carbon, IR spectroscopy, organic carbon | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | Punjab Agricultural University, Ludhiana | en_US |
| dc.sub | Soil Science | en_US |
| dc.subject | Soil Science | en_US |
| dc.theme | MINERAL | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | HUMUS-SOIL MINERAL INTERFACE IN ORCHARD AND FARM SOILS: NANOSCALE APPROACH | en_US |
| dc.type | Thesis | en_US |