Theme 01: Ecophysiology of Grasslands
Description
The objective of this experiment was to determine the environmental influence on seedling emergence of alfalfa and fescue in mixture. We hypothesized that the temperature and precipitation data could be used to estimate field emergence of alfalfa and fescue. A field trial was carried out at Zavalla, Argentina and consisted of sowing a tall fescue – alfalfa mixture at different seeding date (March, April and June). Relationships between the range of temperature, rainfalls and alfalfa and fescue seedling emergence were described by linear regression models. Patterns of emergence and death of alfalfa and fescue seedling were found in the different sowing dates. The measurements performed in other mixed pastures on the area were used to adjust the models. Historical series (1973-1999) of temperature and rainfall data were used to verify the obtained models. The r2 of the correlation between predicted and observed demographic curves of the species was 64 to 97%. The species studied presented varied situations in the phase of emergency and death. When they were sowed in different dates, the April sowing generated an appropriate composition of the mixture. The application of models based on meteorological factors that explain the demographic variations of a forage mixture will allow to plan sowing strategies and to predict the structure of the resulting pastures.
Included in
Effect of Climatic Factors on the Plant Population Dynamics in Temperate Pasture Implantation
The objective of this experiment was to determine the environmental influence on seedling emergence of alfalfa and fescue in mixture. We hypothesized that the temperature and precipitation data could be used to estimate field emergence of alfalfa and fescue. A field trial was carried out at Zavalla, Argentina and consisted of sowing a tall fescue – alfalfa mixture at different seeding date (March, April and June). Relationships between the range of temperature, rainfalls and alfalfa and fescue seedling emergence were described by linear regression models. Patterns of emergence and death of alfalfa and fescue seedling were found in the different sowing dates. The measurements performed in other mixed pastures on the area were used to adjust the models. Historical series (1973-1999) of temperature and rainfall data were used to verify the obtained models. The r2 of the correlation between predicted and observed demographic curves of the species was 64 to 97%. The species studied presented varied situations in the phase of emergency and death. When they were sowed in different dates, the April sowing generated an appropriate composition of the mixture. The application of models based on meteorological factors that explain the demographic variations of a forage mixture will allow to plan sowing strategies and to predict the structure of the resulting pastures.
