Mixed production of Alexandergrass and sorghum under nitrogen fertilization and grazing intensities

Abstract

Annual pasture specie are used in southern Brazil to supply forage in the fall and spring when major forage species have their productivity diminished. Forage sorghum (Sorghum bicolor, (L.) Moench) is a suitable option that has been adopted by farmers due to its high quality as forage. It has been observed that in areas where forage sorghum is cultivated, alexandergrass (Urochloa plantaginea) usually appear as a spontaneous specie. The aim of this study was to observe the effect of two grazing intensities (30 and 60 cm of sward height) and two nitrogen fertilization levels (0 and 200 kg N ha-1) on the quantity (forage mass), quality (CP, ADF, NDF, Lignin, Hemicellulose, Cellulose) and morphological components (stem, leaves, senesced material) of sorghum-alexandergrass mixed pasture grazed by beef cattle. Treatments were arranged in a completed randomized block design with three replications in a 2 x 2 factorial scheme. Forage mass was increased during the evaluation period. In the first period, production was 4,022 kg and it reached 5,233kg DM ha-1 in the third period. Treatments did not affect AG-sorghum mixed pasture botanical profile or quality. It was observed that Sorghum lowered its contribution from 63.4% in the first evaluation period to 21.5% in the third. In contrast, Alexandregrass (AG), contribution increased from 17.9 to 52.7% throughout the evaluation periods. Therefore, the addition of Alexandergrass to a planted sorghum pasture is encouraged because it can extend the grazing period into the fall by prolonging the pasture favorable sward structure and nutritive value.

Salinização secundária no semiárido e seus impactos no solo, na agricultura e cultivo das plantas – uma revisão

“…O sorgo é uma cultura que possui mecanismo de grande adaptabilidade a climas tropicais, representando uma alternativa importante para regiões áridas e com baixos níveis de pluviosidade (Perazzo et al, 2017), onde tem se destacado no uso do tipo forrageiro na alimentação animal (Soares et al, 2020). De acordo com Tabosa et al (2013), estas características adaptativas possibilitam seu cultivo numa vasta variedade de solo e de clima, o que o qualifica como uma cultura de grande capacidade de crescer em condições ambientais adversas (Guo et al, 2015).…”

Nitrogen nutrition index and morphogenesis in Alexandergrass of the Central Depression of Rio Grande do Sul

“…In the southern region, in the summer period, some areas used for livestock farming have a good coverage with Alexandergrass (Urochloa plantaginea (Link) Hitch). The species presents itself spontaneously and, due to its tillering potential, forage accumulation (RESTLE et al, 2002;SARTOR et al, 2011;COSTA et al, 2011) and good adaptation to the soil and climate conditions of the southern region (BERGOLI et al, 2019) has been used as forage in pastoral systems (SOARES et al, 2020). Alexandergrass allows the adequate conversion into animal product, enabling the mating of beef heifers from 15 months of age (COSTA et al, 2011;ELOY et al, 2014, SALVADOR et al, 2014, average daily gain above 0.6 kg animal -1 day -1 in beef heifers (COSTA et al, 2011;SALVADOR et al, 2014;NEGRINI et al, 2018) and stocking rate of 1.600 to 2.400 kg ha -1 of body weight (RESTLE et al, 2002;NEGRINI et al, 2018).…”

Regulation of photosynthetic material production by inter-root microbial extinction and metabolic pathways in sorghum under different nitrogen application patterns

“…The richest habitat for biodiversity on earth is the soil, which is rich in organic and inorganic material that provides habitat for various biological communities 16 , 17 . Soil microorganisms are involved in ecological processes such as nutrient decomposition and supply, and they are an essential component of growth and yield formation 18 .…”