Extending the BASGRA model for timothy grass with functions to simulate impacts of climate change and sward management on yield and nutritive value.

Abstract

Grass-based dairy and meat production constitute the economic backbone of agriculture in Northern Europe including Scandinavia. Timothy (Phleum pratense L.) is one the most important forage grasses in Sandinavia as well as in high latitude regions in North America and Japan. Grassland productivity is expected to be affected by climate change. Process-based models for weather dependent grass growth can assist farmers and plant breeders in adapting to climate change by simulating different options. These models can also be used to investigate different management options such as the prediction of the optimal harvest time for use in tactical planning at farm level under prevailing conditions. The BASGRA model was originally developed to investigate the interaction between the weather, soil and cutting regime on forage dry-matter yield. Recently, BASGRA was extended with functions for simulating nutritive value including crude protein, NDF fibres and fibre digestibility. The aim of this presentation is to give a brief overview of the new version of BASGRA, and to show an example of application of the model to multi-year simulation of timothy growth, yield and nutritive value at two sites in Norway under current and projected future climate conditions, including different fertilizer levels and cutting regimes. Information about the impact of climate change and management on sward nutritional value from such simulations is of particular importance to understand the interaction between these factors and livestock production, and thus to design livestock production systems for future climates.