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| Author(s): |
Fernando de Oliveira Alari
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Jaboticabal. 2016-02-24. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal |
| Defense date: | 2016-01-29 |
| Advisor: | Euclides Braga Malheiro; Ana Cláudia Ruggieri |
| Abstract | |
The emission of greenhouse gases by agriculture and livestock has caused a gradual increase in temperature, In view of that the knowledge systems to mitigate these gases proves vital. The objective of this research was to evaluate the flow of CO2, N2O and CH4 in massai grass pastures (Panicum maximum cv Massai) with intermittent stocking with sheep in silvopastoral system. The experiment was conducted at Forage Crops sector, FCAV, UNESP Jaboticabal, SP, in the period from October 2012 to October 2014. The research evaluated different sheep management systems in massai grass pastures, with or without the presence of eucalyptus, which resulted in four treatments: silvipatoril with eucalyptus in spacing 6.0 × 1.5 m with grazing and fertilizing the massai grass (E1); silvipatoril with eucalyptus in spacing 12.0 × 1.5 m with grazing and fertilizing the massai grass(E2); without eucalyptus system with grazing and fertilizing the massai grass (WE) and a fourth system without eucalyptus, without grazing and fertilizing the massai grass (WEPF). It were used sheep 25 kg average weight, managed on intermittent stocking.The entry of animals in paddocks occurred with light interception (LI) of 95%. The animals were removed when the plants achieved 20 cm height, after three days of grazing. They evaluated the height, dry matter forage (DM), morphological components of forage (dry matter leaf (DL), dry matter of stem (DS) and dry matter of dead material (DD)) and chemical composition of massaigrass (ADF% NDF,% lignin% and protein%). These evaluations were carried out according to a randomized block design with six replications, in repeated measurements scheme in time. Were also assessed the estimated forage intake, rumen CH4 production, production of CH4, N2O and CO2 in the soil and is used in these assessments a completely randomized design, also in installments scheme subdivided in time. For ruminal CH4 production and consumption five animals were used per treatment in reviews CH4 flow, N2O, and CO2 in the soil, closed chambers also being used five replicates per treatment. Only the variable N2O flux found a significant difference between treatments (P<0.05), while the WEPF treatment showed smaller favors in the first three cycles and values different from other treatments in the fourth pasture cycle. The CH4 flow in the first year, DS pre grazing and ADF in the second year and DD in pre grazing in the two experimental years, showed a linear behavior (P<0.05) over the grazing cycles. The N2O flow in the first year, lignin and protein in the second and DL pre grazing in the two experimental years, presented quadratic behavior (P<0.05). Already for ADF, lignin and protein in the first year, DM pre grazing DF post grazing and NDF in the second year, and height and DD post grazing in the two experimental years, had cubic effect (P <0.05). The rainy season has higher CO2 emission levels when compared to the dry season (P>0.05), showing a decrease of 44.46% from 2.33 ol m².s-1. However we can conclude that the introduction of trees did not modify the emission of CO2, N2O and CH4, and only climatic factors changed its flows. (AU) | |
| FAPESP's process: | 12/14910-6 - Balance of greenhouse gases in system silvopastoral. |
| Grantee: | Fernando de Oliveira Alari |
| Support Opportunities: | Scholarships in Brazil - Doctorate |