Morphogenesis, biomass and nutritive value of Panicum maximum under different shade levels and fertilizer nitrogen rates

Abstract

Panicum maximum is important for cattle production in tropical regions, and it responds well to nitrogen (N) fertilization. Many cultivars have exhibited potential for use in silvopastoral systems, although there is limited information on how different levels of N can influence plant growth and nutritive value under shading. Morphogenetic and structural traits, biomass production and nutritive value of two P. maximum cultivars (Tanzânia and Massai) were investigated under three shading levels (0, 37 and 58%) and four N rates (0, 50, 100 and 150 mg N dm À3 ). Plants were grown in pots under shade. Leaf and stem elongation rate and leaf blade length increased with shading and in response to N. Tiller density was reduced with shading, but showed a linear increase fashion with N under full sun and moderate shading. Under intense shading, the tillering showed a quadratic response to N. Plant biomass production increased linearly with N under full sun and moderate shade, but it increased quadratically under intense shade. Crude protein (CP) content increased with shade and N and was greater for Tanzânia than Massai under shade. Contents of NDF and ADF were greater for Massai than Tanzânia. Acid detergent insoluble protein was reduced in Tanzânia under shade, but it increased for Massai. It is suggested that the positive shading effect on CP content may not result in increased nutritional value. Although N fertilization was important for increasing biomass production under full sun and moderate shade, it should be avoided under intense shading.

Influence of low light intensity on growth and biomass allocation, leaf photosynthesis and canopy radiation interception and use in two forage species of Centrosema (DC.) Benth.

“…Therefore, when selecting herbage species for silvopastures, the potential beneficial effects of complementarity in species mixtures to ameliorate contrasting effects of stressing factors (Nicodemo et al., ) should also be further assessed in subsequent studies. In the case of the Centrosema genotypes tested in this study, with contrasting acclimation strategies to shade and seasonal drought (Guenni et al., ), they may be combined with medium shade‐tolerant C 4 grasses like Brachiaria decumbens (Gómez et al., ) and Panicum maximum (Paciullo et al., ) to improve herbage quality and persistence of understory pastures in silvopastoral systems.…”

Productivity and nutritive value of Brachiaria decumbens and performance of dairy heifers in a long‐term silvopastoral system

“…Results obtained from the calculation of the proportion of leaves in the total dry mass revealed that the proportion of leaf blades in the dry mass was 21% higher in the SPS than in the OP (29% vs. 24% leaf blades, respectively, for SPS and OP). In fact, shading induces morphological changes in the pasture in order to increase light uptake (Paciullo et al., ). This result can be associated with small magnitude of differences between systems in heifers weight gain, during experimental period, because the higher leaf blade proportion may have contributed positively to animal nutrition in SPS, despite lower forage mass, tiller population density and forage bulk density in this system than in OP.…”

“…Paciullo et al. () have suggested that an option for sustainable livestock production is the adoption of silvopastoral system (SPS). Among the productive and environmental benefits of the SPS, the following stand out: Improved soil nutrient availability, increased animal production associated with thermal comfort, and higher crude protein (CP) content of forage, as well as the possibility of income diversification in the property (Baliscei et al., ; Kyriazopoulos, Abraham, Parissi, Koukoura, & Nastis, ; Murgueitio, Calle, Uribe, Calle, & Solorio, ; Paciullo et al., ), and environmental services, such as increased biodiversity, sequestration of atmospheric carbon and mitigation of greenhouse gases (Alves, Madari, & Boddey, ; López‐Carrasco, López‐Sánchez, San Miguel, & Roig, ).…”

Light and plant growth‐promoting rhizobacteria effects on Brachiaria brizantha growth and phenotypic plasticity to shade

“…Integrated crop‐livestock‐forestry systems are efficient land‐management alternatives for restoring degraded pastures, increasing food security and promoting carbon sequestration (Dias‐Filho, ; Moraes, Carvalho, Lustosa, Lang, & Deiss, ; Paciullo et al., ; Santos et al., ). However, as the forage grass species planted in integrated systems may be subjected to light restriction, imposed by agricultural crops or tree species, it is necessary to know their agronomic performance under shade, to define their potential use in these systems (Dias‐Filho, ; Gomez, Guenni, & Bravo De Guenni, ; Paciullo et al., ; Pimentel et al., ).…”

“…Phenotypic plasticity relates to the species adaptability to changes in the environment, such as variations in solar radiation, temperature, soil water and nutrient availability (Gomez et al., ; Valladares, Laanisto, Niinemets, & Zavala, ). Shade tolerant plants can adjust their morphophysiology, such as biomass allocation pattern, chlorophyll content and leaf area and thickness to maximize light capture (Paciullo et al., ; Valladares et al., ).…”