Detalhes bibliográficos
| Ano de defesa: |
2016 |
| Autor(a) principal: |
SILVA, Gilka Talita
 |
| Orientador(a): |
CUNHA, Márcio Vieira da |
| Banca de defesa: |
LIRA JUNIOR, Mario de Andrade,
MELLO, Alexandre Carneiro Leão de |
| Tipo de documento: |
Dissertação
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Federal Rural de Pernambuco
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Zootecnia
|
| Departamento: |
Departamento de Zootecnia
|
| País: |
Brasil
|
| Palavras-chave em Português: |
|
| Área do conhecimento CNPq: |
|
| Link de acesso: |
http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6978
|
Resumo: |
The Caatinga has been heavily modified by human activities, with areas with high levels of degradation, and the overgrazing is one of the main factors that influence this process. The nutrient cycling enables maintaining productivity in low-fertility soil environment, grazing environment the main forms of nutrient return is through litter or via excreta animal. The litter has a more uniform distribution and shows slower release of nutrients compared animal excreta, being the main source of plant nutrients long time. The decomposition of this material and subsequent incorporation into the soil is one of the most important processes in the recycling of nutrients. The soil organic matter is one of the most sensitive attributes to the changes caused by human action. The objective is to study the impact of the intensification of grazing through different herbage allowance in Caatinga thinned and enriched on the process of decomposition of leaf litter and the soil organic matter. The survey was conducted at the Academic Unit of Serra Talhada, Federal Rural University of Pernambuco, a Caatinga area enriched with current grass (Urochloa mosambicensis (Hack.) Daudy), Buffel grass (Cenchrus ciliaris L.) and Mororó (Bauhinia cheilantha Steud Bong). They were evaluated the effect of four herbage allowance (2,0; 2,5; 3,0 and 3,5 kg MS forrage / kg of animal PV) on the decomposition of litter grass Stream and Mororó. The decomposition of litter were evaluated at times 0, 4, 8, 16, 32, 64, 128 and 256 days after incubation on the ground. Experimental treatments (forage supplies, species and incubation time) were randomized in blocks with three replications. After the end of each incubation time, the bags were dried in forced-air oven at 55 ° C for 72 hours, the samples were ground in a Wiley mill with 1 mm sieve and were determined the dry matter, organic matter, nitrogen, phosphorus and tannin. The existing litter in different herbage allowance showed spatial and temporal variability in the evaluated forage supplies. The incubation period proposed was not sufficient to cleave 100% of the plant material, the rate of decomposition of litter in Caatinga setting was slow. It was observed the influence of herbage allowance on the rate of decomposition, which may conclude that the microenvironment provided can interfere in the loss of biomass. Fractionation of soil organic matter (SOM) in animal grazing area (the area that was under the influence of the four herbage allowance) and in an area without the animal grazing was also evaluated. We used the physical fractionation method, carried out by decantation and separation by density with the aid of water. Treatments consisted of soil samples collected at 0-10 cm and 10-20 cm in five areas analyzed after air-dried soil samples were sieved through a 2 mm screen and particles larger than 2 mm were discarded. It was observed that the intensities of herbage allowance influence the behavior of the distribution of the fractionation of soil organic matter. The increased supply of fodder (3.5kg DM/kg BW) led to the highest values of the light fraction the area without grazing. Thus, the increased supply of fodder is recommended to increase the levels of soil organic matter. |
