A long-term data sequence (1960-2013) to analyse the sustainability of hay quality in irrigated permanent grassland under climate change

Abstract

Face to climate, land and water use changes, sustainability of crop systems and quality of production is in debate. Long term database concerning hay's mineral contents, dry matter and climate dynamics (rainfall and temperature) have been collected and are used here to argue these questions. Such data are scarce, but here were made available, as they were used to obtain and maintain the certification of the crop, specifically Certified Origin Product (COP) hay. Database collected cover 1960-2013 period, in Crau area, South-Eastern France. Permanent grasslands have been established in this plain since the XVIth century and depend on border irrigation. Statistical tests show that a steady state of the total mineral content and dry matter within long-term has been reached. There is no significant correlation between rainfall and mineral content in hay. Additionally, there is no impact of temperature change on dry matter. Furthermore, the total mineral content of hay is systematically the largest in the third cut and the smallest in the first cut. Our findings suggest that irrigation plays a key role for grasslands sustainability. Irrigated grasslands in Crau area appear as a model of intensive agroecology, with COP productions of high value (hay and animal productions), a crop system, created in the XVIth century and that demonstrates its resilience face to the present global changes. It is however presently jeopardized by urban sprawl.