Yield gap analysis of lucerne (Medicago sativa L.) in the Argentinian Pampas

The amount of pasture grown, consumed and converted into milk on dairy farms is associated with their profitability. Lucerne is the main grazed forage in the Argentinian Pampas and plays a key role by contributing to both milk production and sustainability of dairy systems. However, in the last two decades dairy farms have increased the use of summer crops for silage, winter grazing crops and concentrates. Such change resulted in an intensification of dairy production, i.e. the production of more milk per unit of cultivated land, but at the expense of a reduction in total pasture consumption. This scenario could increase risk and vulnerability of dairy farms. Increasing pasture production and consumption could reduce risk and increase profitability. The difference between potential and actual yields achieved on farm is defined as yield gap, i.e. the difference between potential or theoretical maximum, resource limited and actual yield of crops. Such gap indicates the biophysical scope to intensify yield on a given area (van Ittersum et al. 2013). The profitability of dairy systems in the Argentinian Pampas could increase by reducing the lucerne yield gap in these environments.