ABSTRACT
Integrated production systems have been proposed as alternative to sustainable land use. However, information regarding bacterial community structure and diversity in soils of integrated Crop-Livestock-Forest systems remains unknown. We hypothesize that these integrated production systems, with their ecological intensification, can modulate the soil bacterial communities. However, Yet, it remains unclear whether the modulation of bacterial biodiversity is solely attributable to the complexity of root exudates or if seasonal climatic events also play a contributory role. The objective of this study is to evaluate the impact of monoculture and integrated production systems on bacterial soil communities in the Amazon Biome, Brazil. Three monoculture systems, each with a single crop over time and space (Eucalyptus (E), Crop Soybean (C), Pasture (P)), and three integrated systems with multiple crops over time and space (ECI, PI, ECPI) were evaluated, along with a Native forest serving as a reference area. Soil samples were collected at a depth of 0-10 cm during both the wet and dry seasons. Bacterial composition was determined using Illumina high-throughput sequencing of the 16 S rRNA gene. The sequencing results revealed the highest abundance classified under the phyla Firmicutes, Actinobacteria, and Proteobacteria. The Firmicutes correlated with the Crop in the rainy period and in the dry only ECPI and Forest. For five classes corresponding to the three phyla, the Crop stood out with the greatest fluctuations in their relative abundance compared to other production systems. In cluster analysis by genus during the rainy season, only Forest and ECPI showed no similarity with the other production systems. However, in the dry season, both were grouped with Forest and EPI. Therefore, the bacterial community in integrated systems proved to be sensitive to management practices, even with only two years of use. ECPI demonstrated the greatest similarity in bacterial structure to the Native forest, despite just two years of experimental deployment. Crop exhibited fluctuations in relative abundance in both seasons, indicating an unsustainable production system with changes in soil microbial composition. These findings support our hypothesis that integrated production systems and their ecological intensification, as exemplified by ECPI, can indeed modulate soil bacterial communities.
ABSTRACT
Gliricidia (Gliricidia sepium) is a tree legume that has great potential for use in agriculture because of its multiple-use characteristics. However, there is little information in the literature about the effect of agrisilvicultural systems on nitrogen (N) cycling. This study evaluated the effect of densities of gliricidia on N cycling under an agrisilvicultural system. The treatments were composed of different densities of gliricidia: 667, 1000 and 1333 plants ha-1, with a fixed spacing of 5 m between the alleys. The efficiency of N use was investigated by using the 15N isotope tracer. In each plot, a transect perpendicular to the tree rows was established in two positions: (i) in the corn (Zea mays) row adjacent to the trees, and (ii) in the corn row in the center of the alley. The N fertilizer recovery efficiency ranged from 39% in the density of 667 plants ha-1 to 89% with 1000 plants ha-1. The effect of gliricidia on the N uptake by corn was higher in the central position of the alley with 1000 plants ha-1. The agrisilvicultural system with 1000 plants ha-1 was highly efficient in the recovery of mineral N, representing an excellent option for integrated production systems in tropical regions.
ABSTRACT
The objective was to evaluate animal performance and nutritional characteristics of Brachiaria brizantha cv. BRS Piatã in two integrated systems, during the summer and winter, five years after the initial establishment of the area. The randomized block experimental design was adopted with treatments consisting of a control (five native trees per hectare) and an integrated crop-livestock-forestry (ICLF) system with 227 eucalyptus trees per hectare. Animal performance, canopy height, soil cover, forage mass (leaf, stem and senescent material), and forage nutritive value were evaluated. Differences between systems were observed in forage mass (total, leaf, stem and senescent material), soil cover and forage nutritive value in both seasons. Shading conditions provided by eucalyptus in the ICLF system lead to a reduction in forage mass and neutral detergent fiber content, and to an increase in crude protein and in vitro organic matter digestibility. However, no effect on animal performance was obtained. The presence of trees improves the forage nutritive value without impacting animal performance in integrated systems.(AU)
O objetivo foi avaliar o desempenho animal e as características nutricionais de Brachiaria brizantha cv. BRS Piatã em dois sistemas integrados, durante o verão e o inverno, cinco anos após o estabelecimento inicial da área. O delineamento experimental em blocos ao acaso foi adotado com tratamentos constituídos por um controle (cinco árvores nativas por hectare) e um sistema integrado lavoura-pecuária-floresta (ILPF) com 227 eucaliptos por hectare. Desempenho animal, altura do dossel, cobertura do solo, massa de forragem (folha, caule e material senescente) e valor nutritivo da forragem foram avaliados. Diferenças entre os sistemas foram observadas na massa de forragem (total, foliar, caule e material senescente), na cobertura do solo e no valor nutritivo da forragem em ambas as estações. As condições de sombreamento proporcionadas pelo eucalipto no sistema ICLF levaram a uma redução na massa de forragem e no teor de fibra em detergente neutro e a um aumento na proteína bruta e na digestibilidade in vitro da matéria orgânica. No entanto, nenhum efeito no desempenho animal foi obtido. A presença de árvores melhora o valor nutritivo da forragem, sem impactar o desempenho animal em sistemas integrados.(AU)
Subject(s)
Animals , Brachiaria , Poaceae , Animal HusbandryABSTRACT
O objetivo deste trabalho foi avaliar a pastagem, o desempenho, o conforto térmico e os parâmetros hematológicos de bovinos Nelore na fase de terminação em sistemas integrados de produção agropecuária com duas densidades de árvores (ILPF-1L= 196 árvores ha-1 e ILPF-3L=448 árvores ha-1) e em pleno sol (ILP). Foram avaliados a massa e a composição morfológica da forragem, o ganho médio diário, o ganho de peso por área e a taxa de lotação no verão e no outono, bem como as variáveis climáticas dos sistemas em três horários e parâmetros hematológicos dos animais (n=60). A massa de forragem foi superior no tratamento ILP e no verão (P<0,05). Porém, a redução da massa de forragem nos sistemas ILPFs não interferiu no desempenho dos animais (P>0,05). A temperatura ambiente, a temperatura do globo e o índice de temperatura e umidade foram melhores nos tratamentos com sombreamento e no período da manhã, proporcionando maior conforto aos animais, sendo ainda confirmado pelo menor volume globular dos bovinos em ILP (P<0,05). Conclui-se que os sistemas com componente arbóreo diminuem a massa de forragem, mas essa redução não altera o desempenho dos animais na fase de terminação. Além disso, os sistemas ILPFs melhoram o conforto térmico, entretanto essa melhora não foi suficiente para favorecer o desempenho.(AU)
The objective of this work was to evaluate pasture, performace, thermal comfort, and haematological parameters of Nellore cattle in the finishing phase in integrated crop-livestock systems with two tree densities (ICLF-1L= 196 ha -1 trees and ICLF-3L= 448 ha -1 trees) and in full sun (ICL). The forage mass morphological composition of the pasture average daily gain, weight gain per area, stocking rate of the animals were evaluated in summer and autumn, and the climatic variables of systems we evaluated at three different times, and haematological parameters of the animals (n= 60). The forage mass was higher in the ICL treatment and summer (P<0.05). However, the reduction of the forage mass in the ILPFs systems did not interfere with the performance of the animals (P>0.05). Ambient temperature, globe temperature and temperature and humidity index were better in shade treatments and in the morning, providing greater comfort to the animals, and was also confirmed by the lower globular volume of the bovines in ICL (P<0.05). It is concluded that the systems with trees reduce the forage mass but this reduction does not alter the animals' performance in the finishing phase. In addition, ICLFs improve the thermal comfort of the animals, however, this improvement was not enough to favor their performance.(AU)