CONICET | Buscador de Institutos y Recursos Humanos

ObjectiveAnalyze biomass dynamics accumulation in contrasting canopy structure pasturesMaterials and methodsAt INTA Pergamino Experimental Station (Lat: 33º34´S; Long: 60º34´W), Argentina, they were evaluated different canopy structure pastures including pure pastures and its mixtures in plots (7,5 m2) with a randomized block design and 5 replicates. The pastures were sown 04/05/2016 in a Typic Argiudoll (pH=6; organic matter=2,9 % and extractable phosphorus=24,7 ppm). Treatments consisted in seven different pastures: i) AA: alfalfa, ii) FC: north Europe tall fescue, iii) FM: Mediterranean tall fescue, iv) AA-FC: alfalfa and north Europe tall fescue, v) AAFM: alfalfa and Mediterranean tall fescue, vi) FC-FM: north Europe and Mediterranean tall fescue, vii) AA-FC-FM: alfalfa, north Europe and Mediterranean tall fescue. The alfalfa cultivar used was Bar Pal 9242 without winter dormancy. Tall fescue cultivars differ in their phenology, concentrated during winter-spring for Mediterranean type. The cultivars used were north Europe type cv. Palenque plus INTA and Mediterranean type cv. Flecha. Mixtureswere sown in alternate rows. Drought conditions were avoided through occasional sprinkler irrigation. Aerial dry matter biomass per component (alfalfa and tall fescue) was measured cutting a quadrat per plot (1m2) at 5 cm height considering 500 ± 50 degree day sum for each period, except during establishment with a higher degree days accumulated. The statistical analysis for biomass dynamics was performed with a mixed model with repeated measures in time considering blocks, pasture, cutting and the interaction between pasture and cutting. Totalbiomass per each component was analyzed with ANOVA. Treatment average values were compared with Fischer´s test (p< 0.05).ResultsSeasonal distribution of biomass was different between pastures (Figure 1.a.), being the interaction between pasture and cutting highly significant (p