Densidade de Fluxo de Fótons (DFF) em um sistema de Integração Lavoura-Pecuária-Floresta (ILPF)

Abstract

Resumo: Este estudo foi realizado em um sistema de produção integrado lavoura-pecuária-floresta no município de Cachoeira Dourada, Goiás, Brasil. A pesquisa colabora para um melhor entendimento da interação planta-ambiente, esta foi realizada com o objetivo de analisar a entrada de luz em dois períodos diferentes (estação seca e chuvosa). Para a coleta da Densidade de Fluxo de Fótons (DFF) (µmol.m-2 .s-1 ) foi utilizado dois sensores de quanta LI-250 A, Li-cor Inc., USA, na faixa fotossinteticamente ativa. A coleta foi realizada de hora em hora, com início às 9h45min e término às 17h45min. Coletou-se o DFF controle -a pleno sol, e as demais coletas foram realizadas em quatro pontos: (1-no centro do renque de árvores, 2 -a 5m do renque, 3 -a 10m do renque e 4 -a 15m do renque), sendo que em cada ponto se obteve mais 4 repetições. De acordo com os resultados obtidos se verificou que houve diferenças entre os pontos escolhidos, sendo o ponto 10 e 15 metros com maior recebimento de faixa de Radiação Fotossinteticamente Ativa (RFA). Portanto, o sistema Integrado Lavoura-Pecuária-Floresta (ILPF) não reduziu a Densidade de Fluxo de Fótons (DFF). A maior DFF foi verificada no período de seca, porém, a maior variação da DFF foi encontrada no período chuvoso. Quanto maior à distância em relação aos renques, com eucaliptos, maior à incidência de radiação solar. Palavras -chave:Luminosidade; Produtividade; Fotossíntese; Agrossilvipastoril. Photon flux density in a crop livestock forest systemAbstract: This study was conducted in a crop livestock forest system in Cachoeira Dourada, Goiás state, Brazil. Aiming to contribute to a better understanding about plant-environment interaction, this study had as objective to analyze light input in two different periods (dry and wet season). For photon flux density (PFD) measurement, two quanta sensors (LI-250 A, Licor Inc., USA) were used, in photosynthetically active band. Data collection was done in each hour, starting at 9:45 and ending at 17:45, and also collected the control to full sun, and other collections in: (1 in the center of the row of trees, 2 -at 5 m of hedgerow 3 -at 10m of hedgerow 4-at 15m of hedgerow), in each point 4 replications were obtained. According to the observed results, it was possible to verify that there were differences among the chosen points, being the points 10 and 15 meters the ones that receive the most range of PAR.most receiving range (PAR). Therefore, CLFS system did not reduce photons flux density. Highest PFD was verified during the dry season however the highest variation was verified in the wet period. The greater the distance from the rows with trees, the greater the incidence of solar radiation.

Eucalipytus Litter Contribution to the Integrated Crop-Livestock System

“…According to these authors, variations in nutrient content in different litter compartments can be observed in the same species, given site and plants' features, and features of the element itself. Based on Leite et al (2011), variations in the same element can happen within the same forest species, although Guimarães;Calil (2017) stated that nutrient concentration in each compartment is related to its function.…”

“…Production cost reduction and income diversification are among the benefits from this system (ALVARENGA et al, 2010), as well as water, soil and climate resource conservation, recovery of degraded areas, natural pest and disease control, greenhouse gas emission reduction (BALBINO et al, 2011), changes in microclimate such as temperature and humidity (GUIMARÃES;CALIL, 2017), light, wind, pH andC andN stock (BENAVIDES et al, 2009), and soil quality changes naturally motivated by nutrient cycling due to treecomponent presence.…”

“…Despite the several scientific publications reporting such deposition, accumulation and decomposition in native and planted forests in tropical and temperate regions, recent research address litter dynamics in integrated production systems (GUIMARÃES;CALIL, 2017;FREITAS et al, 2013).…”

Nutrient stock in the forest component in a crop-livestock-forest integration system in Central Brazil

“…It is near and washed by the waters of the Paranaíba River and the Rio Meia Ponte (GUIMARÃES et al, 2016).…”

“…with regards to the different litter compartment: leaves, branches, bark and wood (GUIMARÃES et al, 2016).…”