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Our objective was to measure chemical composition and anatomy of 5 Megathyrsus maximus (syn. Panicum maximum) genotypes, when grown in combination with eucalypts in a silvopastoral system. Cultivars Massai, Mombaça, BRS Tamani, Tanzânia and intraspecific hybrid accession PM44 were evaluated in full sun and a silvopastoral system at 5 different distances from eucalyptus tree rows. The experimental design was a randomized block in split plot with 2 replications. Plots corresponded with genotypes and subplots with sampling points within the system. Total forage and leaf biomass as well as nutritive value und tissue proportions were evaluated. Our results showed a decrease in biomass as radiation incidence decreased. Forage biomass was greatest in BRS Tamani and Mombaça and lowest in PM44. There was a significant interaction between sampling points and genotype for nutritive value variables, such as crude protein, in vitro digestibility of organic matter, cellulose, hemicellulose and lignin-S, while tissue proportions were not affected by the interaction between sampling points and genotypes. Genotype had more pronounced effects on chemical composition and anatomical characteristics than did sampling points. The leaves of Mombaça were the longest and had greatest total cross-sectional area, and this genotype showed greater proportions of sclerenchyma and vascular tissues than other cultivars and the lowest proportion of mesophyll. The greatest proportion of parenchyma bundle sheaths was also found in Mombaça leaves. Genotypes PM44 and Tanzânia had the lowest proportions of sclerenchyma, and PM44 and BRS Tamani had the lowest proportions of vascular tissues. On the other hand, PM44 and Tanzânia had the greatest proportions of mesophyll. BRS Tamani was comparable with the most used cultivars, Mombaça and Tanzânia, and had forage quality slightly superior to that of Mombaça. Tropical grasses growing under shade can potentially produce less forage but with better nutritive value, in terms of chemical composition and tissue proportions, than grasses grown under full sun. However, as the degree of shading in silvopastoral systems does not occur uniformly across the whole area, the improved nutritive value would not be uniform and may not be very prominent overall.
Mariana Pereira; Roberto Giolo De Almeida; Manuel Claudio Motta Macedo; Valéria Ana Corvalã Dos Santos; Erick Lemes Gamarra; Joaquín Castro-Montoya; Beatriz Lempp; Maria Da Graça Morais. Anatomical and nutritional characteristics of Megathyrsus maximus genotypes under a silvopastoral system. Tropical Grasslands-Forrajes Tropicales 2021, 9, 159 -170.
AMA StyleMariana Pereira, Roberto Giolo De Almeida, Manuel Claudio Motta Macedo, Valéria Ana Corvalã Dos Santos, Erick Lemes Gamarra, Joaquín Castro-Montoya, Beatriz Lempp, Maria Da Graça Morais. Anatomical and nutritional characteristics of Megathyrsus maximus genotypes under a silvopastoral system. Tropical Grasslands-Forrajes Tropicales. 2021; 9 (2):159-170.
Chicago/Turabian StyleMariana Pereira; Roberto Giolo De Almeida; Manuel Claudio Motta Macedo; Valéria Ana Corvalã Dos Santos; Erick Lemes Gamarra; Joaquín Castro-Montoya; Beatriz Lempp; Maria Da Graça Morais. 2021. "Anatomical and nutritional characteristics of Megathyrsus maximus genotypes under a silvopastoral system." Tropical Grasslands-Forrajes Tropicales 9, no. 2: 159-170.
Integrated-crop-livestock-forestry (ICLF) systems are currently promoted as a measure for sustainable intensification of agricultural production. However, due to complex interactions among ICLF components, we are still lacking evidence about the system’s resilience regarding water availability, especially for regions characterized by pronounced wet and dry seasons and frequent droughts. For a mature ICLF system in the Cerrado biome of central-west Brazil comprising rows of eucalyptus trees (Eucalyptus grandis x Eucalyptus urophylla, H13 clone) at a spacing of 22 m in combination with Brachiaria brizantha cv. BRS Piatã pasture we continuously measured soil moisture (SM) until 1 m depth and supported this data with measurements of photosynthetically active radiation (PAR) and aboveground green grass biomass (AGBM) across transects between the tree rows for almost two years. Across the seasons a distinct gradient was observed with SM being lower close to the tree rows than in the space between them. During winter SM decreased to critical values near the tree lines in the topsoil. During spring and summer, incident PAR was 72% and 86% lower close to the trees than at the center point. For autumn and winter PAR was more evenly distributed between the tree rows due to inclination with notably up to four times more radiation input near the tree lines compared to spring and summer. AGBM showed a clear distribution with maximum values in the center and about half of the biomass close to the tree rows. Our data suggest that, restrictions in AGBM accumulation shifted among seasons between water limitations in winter and light limitations during summer. Interestingly, SM changes during wetting and drying events were most pronounced in subsoils near the tree rows, while the topsoil showed much less fluctuations. The subsoil in central position showed the lowest SM dynamics in response to drought maintaining a relative high and constant SM content, therefore functioning as important water reservoirs likely improving the resilience of the system to drought stress. Results of this study could help to improve management and the design of ICLF systems in view of sustainability and resistance to (water) crises but should be further supported by in depth analysis of soil water dynamics as affected by climate gradients, soil types and different management practices.
Sarah Glatzle; Sabine Stuerz; Marcus Giese; Mariana Pereira; Roberto de Almeida; Davi Bungenstab; Manuel Macedo; Folkard Asch. Seasonal Dynamics of Soil Moisture in an Integrated-Crop-Livestock-Forestry System in Central-West Brazil. Agriculture 2021, 11, 245 .
AMA StyleSarah Glatzle, Sabine Stuerz, Marcus Giese, Mariana Pereira, Roberto de Almeida, Davi Bungenstab, Manuel Macedo, Folkard Asch. Seasonal Dynamics of Soil Moisture in an Integrated-Crop-Livestock-Forestry System in Central-West Brazil. Agriculture. 2021; 11 (3):245.
Chicago/Turabian StyleSarah Glatzle; Sabine Stuerz; Marcus Giese; Mariana Pereira; Roberto de Almeida; Davi Bungenstab; Manuel Macedo; Folkard Asch. 2021. "Seasonal Dynamics of Soil Moisture in an Integrated-Crop-Livestock-Forestry System in Central-West Brazil." Agriculture 11, no. 3: 245.