Emissão de CO² e atributos físicos em diferentes sistemas de preparo do solo

• Autor(a) principal: Simon, Carla da Penha
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/8231
• topic: Geoestatistic; No-tillage; Conventional tillage; Minimum tillage; Native forest; Geoestatística; Preparo convencional; Cultivo mínimo; Sistema de plantio direto; Mata nativa; Agronomia; Atmosfera do solo; Geologia - Métodos estatísticos; 63

Soil from the agricultural environment can be as a carbon emitter or sink. Soil CO2 emissions (FCO2) depend on the adoption of management practices, such as soil preparation systems. The objective of this study was to evaluate the influence of different tillage systems, no-tillage (NT), conventional tillage (CT), minimum tillage (MT) and native forest area as reference (NF) for FCO2 and relationship with soil attributes. The study was carried out at the IFES Campus Santa Teresa-ES, between the months of August / 2016 and March / 2017. To evaluate the FCO2, an infrared gas analyzer LI-8100A was used, with the simultaneous reading of the temperature and humidity of the soil; and removal of soil samples close to the installed FCO2 collars, in the depth range 0 - 0.20 m, in order to determine soil attributes: density (Bd), total pore volume (TPV), macroporosity (Ma), microporosity (Mi) and mechanical resistance to soil penetration (RSP). Geostatistical analyzes of semivariograms parameters were estimated using Geostatistical for environmental science® GS + Software. In the study areas FCO2 ranged from 0.53 to 4.99 μmol CO2 m-2 s -1 , the spatial dependence indices in the NT, CT and MT areas were 95, 50% and 37.9 respectively. The spatial behavior of the variables in the study presented the classifications of moderate to low spatial variability. Chapter 2: using univariate statistics, each soil preparation system plus reference area (NF) were considered as treatments, with 6 replications, totaling 24 experimental units. Where the studied variables were: Bd, TPV, Ma, Mi, RSP and total organic carbon (TOC). The analyzes were performed using the SisVar® statistical program. FCO2 presented a significant difference between NT and CT; mean values for NT, NF, MT and CT (2.30, 2.25, 2.18 and 1.39 μmol CO2 m-2 s -1 ); COT presented its highest value in the Mata area (32.95 g kg-1 ), differing statistically from the other areas. It was observed that lower emissions can be expected from systems with low organic carbon input.