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| Author(s): |
Bruna de Oliveira Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Jaboticabal. 2017-08-15. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal |
| Defense date: | 2017-07-17 |
| Advisor: | Newton La Scala Junior; Carolina Fernandes; Daniel De Bortoli Teixeira |
| Abstract | |
The development of the Brazilian agricultural sector necessarily implies a greater concern with diverse environmental impacts caused by the sector, among them the CO2 emissions from soil and crop management in the production systems. This study aimed to investigate the CO2 emission associated to physical properties in the short term after soil management submitted to different intensities. The study was conducted in three adjacent areas, measuring 10 × 3 m each, in which two soil tillage systems were performed: (i) rotary hoe + conventional harrow representing a much more intense soil tillage (PI); (ii) disc plowing + disc harrowing, characterizing a reduced soil tillage (PR), and in the third area was no-tillage (SD), without disturbance. They were carried out daily evaluations of soil CO2 emissions (FCO2), temperature and soil moisture, bulk density, soil resistance to penetration, water-free porosity, mean weight diameter, stability indices of soil aggregates, total organic carbon and particulate organic carbon, over a period of 29 days. On the first day after management, FCO2 was 87% higher in PI (3.86 μmol m-2 s-1) when compared to PR (2.06 μmol m-2 s-1) and was 147% higher when compared to area without disturbance (1.56 μmol m-2 s-1).The physical soil attributes: bulk density, resistance to penetration; showed lower variation from day 12 after soil management, this effect was considered in this study as a natural process of soil consolidation, and this process may also have influenced the temporal variation of soil CO2 emission. However, future studies involving a longer period of time are necessary in order to establish more concrete relationships. However, future studies involving a longer period of time are necessary to fortify the interrelations observed in this study. The distribution of pore classes are important physical attributes to explain the temporal variations of the soil CO2 emission, and these classes are influenced by the adopted management. Therefore, the study of these attributes should be taken into account when evaluating the variation of CO2 emission in agricultural soils. (AU) | |
| FAPESP's process: | 15/25615-3 - Soil CO2 emission after management associated to soil physical properties under no-tillage system |
| Grantee: | Bruna de Oliveira Silva |
| Support Opportunities: | Scholarships in Brazil - Master |