Panicum maximum cv. Aries Establishment under Weed Interference with Levels of Light Interception and Nitrogen Fertilization

Abstract

The aim of this study was to evaluate the establishment of the pasture of Panicum maximum cv. Aries in an environmentally protected area under levels of interspecific interaction with the weed community. The experiment started after sowing P. maximum, and it was carried out in a randomized block design with four replications and the following factors: 3 light interception levels, 2 nitrogen rates, and 7 weekly sampling dates along pasture establishment (3x2x7). The light interception treatments, determined by photosynthetically active radiation, were given by mowing weeds over the canopy of P. maximum at 40% and 70% light interception, and no mowing (uncontrolled growth of weeds and P. maximum). Topdressing application of nitrogen in the form of urea was performed or not (0 or 200 kg N ha-1). The plant community was evaluated by number of species, dry matter accumulation, and density, and phytosociological indices were determined. The relative importance and dry matter accumulation of P. maximum were greater after nitrogen fertilization, which favored the species against weed competition. In contrast, there was lower weed density without nitrogen fertilization. Mowing weeds at 40% of light interception enabled P. maximum to accumulate more dry matter, while there was no difference between mowing weeds at 70% light interception and growing the forage crop freely with weeds. Reducing weed light interception as well as nitrogen fertilization, and consequently reducing the competitive ability of the weed, favored the establishment of P. maximum in diversified agro-ecosystems.

Aries Guineagrass (Megathyrsus maximus Jacq cv. Aries) pasture establishment without chemical control in an environmentally protected area

“…According to the botanical composition (Table 1) at the Guineagrass establishment, it is possible to affirm that these plants are commonly present in the region. Kruchelski et al (2019) studied the weed species in the establishment of Aries Guineagrass in same area and similar species (Table 2) were identified.…”

Rehabilitación de praderas degradadas en el trópico de México

“…Una de las características de las praderas degradadas es la presencia de altas poblaciones de malezas, que ocupan los espacios que van dejando los pastos, por lo que, eventualmente la competencia por agua, luz y nutrientes se vuelve crítica (38) . Las malezas pueden aprovechar estos recursos mejor que los pastos, ya que agrupan a diversas especies, con diferentes necesidades y habilidades y una distribución espacial y estado de desarrollo no uniformes (39) , por lo que tienen la capacidad de explorar más eficientemente el ambiente en busca de los factores esenciales para el crecimiento, reduciendo su disponibilidad para los pastos (40,41) .…”