Soil organic matter in oxisols of the Brazilian cerrados
Little is known about the sustainability of cultivation systems in the Brazilian savannas, also known as the Cerrados, despite its increasing significance for that country`s agriculture. To characterize management effects and follow alterations of organic compounds in different fractions, we studied...
| Main Authors: | , , , |
|---|---|
| Format: | Book Chapter |
| Language: | Inglés |
| Published: |
International Center for Tropical Agriculture
1999
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/55130 |
| _version_ | 1855531513209159680 |
|---|---|
| author | Neufeldt, Henry Resck, DVS Ayarza, Miguel Angel Zech, W. |
| author_browse | Ayarza, Miguel Angel Neufeldt, Henry Resck, DVS Zech, W. |
| author_facet | Neufeldt, Henry Resck, DVS Ayarza, Miguel Angel Zech, W. |
| author_sort | Neufeldt, Henry |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Little is known about the sustainability of cultivation systems in the Brazilian savannas, also known as the Cerrados, despite its increasing significance for that country`s agriculture. To characterize management effects and follow alterations of organic compounds in different fractions, we studied whole-soil samples and particle-size separates from clayey and loamy Oxisols under crops, pastures, reforested sites, and savanna. We assessed soil organic carbon (SOC), polysaccharides, and CuO oxidation products (VSC-lignin). Few changes were found in SOC contents of topsoil (0-12 cm) under different land uses after 10-20 years. But organic carbon clearly diminished under continuous cropping on the loamy soil and under reforestation with pine on the clayey soil. Management effects on SOC were more apparent in sand fractions, suggesting that particulate organic matter (POM) was affected most. In the clay fraction, only minor effects were noted. Carbon-normalized polysaccharide contents were enriched under pastures and depleted under pine, but generally followed a similar distribution to that of SOC. Overall, both polysaccharides and VSC-lignin were closely related to soil porosity. Plant-derived polysaccharides and lignin contents were probably regulated by water availability to soil microbes, so that decomposition was usually more advanced in the clayey soils. Ten years of continuous cropping lowered litter inputs, thus reducing POM, whereas humified organic matter (OM) was unaffected. Planting eucalyptus or well-managed pastures, which produce high amounts of POM, would thus rapidly reverse soil degradation. Continuous cropping does eventually reduce the humified fraction and results in a substantial loss of soil fertility, which is only slowly reversible. |
| format | Book Chapter |
| id | CGSpace55130 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 1999 |
| publishDateRange | 1999 |
| publishDateSort | 1999 |
| publisher | International Center for Tropical Agriculture |
| publisherStr | International Center for Tropical Agriculture |
| record_format | dspace |
| spelling | CGSpace551302024-01-09T09:49:01Z Soil organic matter in oxisols of the Brazilian cerrados Neufeldt, Henry Resck, DVS Ayarza, Miguel Angel Zech, W. savannas particle size polysaccharides soil organic matter lignins sabanas oxisoles tamaño de la partícula estructura del suelo polisacáridos materia orgánica del suelo ligninas Little is known about the sustainability of cultivation systems in the Brazilian savannas, also known as the Cerrados, despite its increasing significance for that country`s agriculture. To characterize management effects and follow alterations of organic compounds in different fractions, we studied whole-soil samples and particle-size separates from clayey and loamy Oxisols under crops, pastures, reforested sites, and savanna. We assessed soil organic carbon (SOC), polysaccharides, and CuO oxidation products (VSC-lignin). Few changes were found in SOC contents of topsoil (0-12 cm) under different land uses after 10-20 years. But organic carbon clearly diminished under continuous cropping on the loamy soil and under reforestation with pine on the clayey soil. Management effects on SOC were more apparent in sand fractions, suggesting that particulate organic matter (POM) was affected most. In the clay fraction, only minor effects were noted. Carbon-normalized polysaccharide contents were enriched under pastures and depleted under pine, but generally followed a similar distribution to that of SOC. Overall, both polysaccharides and VSC-lignin were closely related to soil porosity. Plant-derived polysaccharides and lignin contents were probably regulated by water availability to soil microbes, so that decomposition was usually more advanced in the clayey soils. Ten years of continuous cropping lowered litter inputs, thus reducing POM, whereas humified organic matter (OM) was unaffected. Planting eucalyptus or well-managed pastures, which produce high amounts of POM, would thus rapidly reverse soil degradation. Continuous cropping does eventually reduce the humified fraction and results in a substantial loss of soil fertility, which is only slowly reversible. 1999 2015-01-28T14:17:27Z 2015-01-28T14:17:27Z Book Chapter https://hdl.handle.net/10568/55130 en Open Access International Center for Tropical Agriculture Neufeldt, Henry; Resck, Dimas Vital Siqueira; Ayarza, Miguel Angel; Zech, Wolfgang. 1999. Soil organic matter in oxisols of the Brazilian cerrados. In: Thomas, Richard J.; Ayarza, Miguel Angel (eds.). Sustainable land management for the oxisols of the Latin American savannas: Dynamics of soil organic matter and indicators of soil quality. Centro Internacional de Agricultura Tropical (CIAT), Cali, CO. p. 89-109. (CIAT publication no. 312) |
| spellingShingle | savannas particle size polysaccharides soil organic matter lignins sabanas oxisoles tamaño de la partícula estructura del suelo polisacáridos materia orgánica del suelo ligninas Neufeldt, Henry Resck, DVS Ayarza, Miguel Angel Zech, W. Soil organic matter in oxisols of the Brazilian cerrados |
| title | Soil organic matter in oxisols of the Brazilian cerrados |
| title_full | Soil organic matter in oxisols of the Brazilian cerrados |
| title_fullStr | Soil organic matter in oxisols of the Brazilian cerrados |
| title_full_unstemmed | Soil organic matter in oxisols of the Brazilian cerrados |
| title_short | Soil organic matter in oxisols of the Brazilian cerrados |
| title_sort | soil organic matter in oxisols of the brazilian cerrados |
| topic | savannas particle size polysaccharides soil organic matter lignins sabanas oxisoles tamaño de la partícula estructura del suelo polisacáridos materia orgánica del suelo ligninas |
| url | https://hdl.handle.net/10568/55130 |
| work_keys_str_mv | AT neufeldthenry soilorganicmatterinoxisolsofthebraziliancerrados AT resckdvs soilorganicmatterinoxisolsofthebraziliancerrados AT ayarzamiguelangel soilorganicmatterinoxisolsofthebraziliancerrados AT zechw soilorganicmatterinoxisolsofthebraziliancerrados |