CARACTERISTICAS AGRONOMICAS DE Urochloa mosambicensis EM FUNCAO DO NITROGENIO E FOSFORO

Abstract

RESUMOObjetivou-se avaliar as características agronômicas do capim-corrente (Urochloa mosambicensis) em função da adubação fosfatada e nitrogenada no Semiárido de Pernambuco. Adotou-se o delineamento inteiramente casualizado, no esquema fatorial 2 x 2 (presença e ausência de nitrogênio x presença e ausência de fósforo), com quatro repetições. O número médio de perfilhos por planta foi 10,31. O comprimento médio de colmo foi 71,45 cm. A taxa média de alongamento de colmo foi 2,38 cm/dia. O número médio de folhas em expansão e expandida foi 3,38 e 3,44, respectivamente. O total de folhas por perfilho variou entre 11,5 e 7,0. O uso da adubação nitrogenada associada à fosfatada proporcionou um incremento no número de folhas senescentes (3,75) em relação à ausência desses dois nutrientes (1,25) ou a ausência de nitrogênio (1,00), entretanto foi similar a presença de nitrogênio. A adubação nitrogenada proporcionou incremento (P < 0,10) na massa de lâmina foliar e aumentou em 455% a produção de massa verde do capimcorrente. Em relação à massa seca, observou-se maior acúmulo de fitomassa do capim-corrente adubado com nitrogênio, independente da adubação fosfatada. A adubação nitrogenada aumenta a produção de fitomassa do capim-corrente, devendo ser recomendada como prática de manejo dessa cultura.

Urochloa Grass Growth as a Function of Nitrogen and Phosphorus Fertilization

“…It is important to point out that the analysis of the soil in the present rehearsal indicated 40 mg dm -3 of phosphorus (P 2 O 5 ), a value considered adequate for urochloa grass (BEZERRA et al, 2017). However, phosphate fertilization with simple superphosphate (150 kg.ha -1 ) in a soil with clay content below the limit of 15%, favored a higher plant height of urochloa grass, regardless of nitrogen, reinforcing the important role of phosphorus in the morphogenesis of this stoloniferous grass.…”

“…The Brazilian soils, for the most part, contain low levels of phosphorus, one of the elements that most limits the productivity of forages. Phosphorus has a direct influence on root system growth and tillering of forage grasses (BEZERRA et al, 2017). Thus, in order to obtain sustainable crops and high forage yields in these soils, it becomes necessary and essential phosphorus fertilization, as well as nitrogen fertilization, which plays an important role in plant morphogenesis, promoting increase in the metabolism and rates of enzymatic reactions (BEZERRA et al, 2017).…”

“…Phosphorus has a direct influence on root system growth and tillering of forage grasses (BEZERRA et al, 2017). Thus, in order to obtain sustainable crops and high forage yields in these soils, it becomes necessary and essential phosphorus fertilization, as well as nitrogen fertilization, which plays an important role in plant morphogenesis, promoting increase in the metabolism and rates of enzymatic reactions (BEZERRA et al, 2017). Nitrogen is the mineral element that plants require in larger quantities, under conditions of disability, nitrogen is the main limiting factor to plant growth and can significantly affect forage grasses productivity (MARTINS et al, 2008;MARTUSCELLO et al, 2015).…”

“…(IKEDA et al, 2013;MATA et al, 2011), in Cynodon (PEREIRA et al, 2012), in millet (ALMEIDA et al, 2017, among others. Recent studies have evaluated the agronomic characteristics of Urochloa mosambicensis, using nitrogen and phosphate fertilization (BEZERRA et al, 2017;, cutting height management (SÁ JÚNIOR et al, 2018) and leaf area (LEITE et al, 2017;LUCENA et al, 2018).…”

Forage availability and weight gain of goats on caatinga enriched with Urochloa trichopus (Hochst.) Stapf subjected to fallowing and fertilized with phosphate

“…According to Bezerra et al (19) , phosphorus plays a key role in the life cycle of plants, being present in metabolic processes of plants directly or indirectly related to energy expenditure. Also, according to these authors, phosphorus fertilization is necessary to achieve high phytomass productivity, due to its important role in plant morphogenesis, promoting an increase in metabolism and rates of enzymatic reactions.…”