In order to assess the variability of sainfoin varieties and characterise them we established a variety trial under irrigation in Zaragoza, Spain, and evaluated it over a three year period Varieties included a selection of 23 landrace and cultivars representing the material available. This collection was assess for several agronomic characteristics such as the growth habit, dry matter production, regrowth capacity, mortality and total dry matter under a cutting regime of 5 cuts a year. The quality of the forage produced was evaluated in terms of fibres, crude protein and tannins contents. 

We found a large variability among varieties, especially on agronomic level: 

• plant showed a growth habit range from erect to prostate
• a total production between 1041 g DM/plant and 1776 g DM/plant in two productive cycles
• mortality rate between 50% and 78% after three year of cropping
• flowering intensity range from 23 to 97% of the plants flowering first year

Sainfoin showed a characteristic distribution of forage production along the year. DM showed a clear peak in the first cut, representing 45% of the total annual yield, dramatically declining thereafter. Eight varieties coming mainly form Eastern Europe and the Mediterranean area presented an outstanding production level, three of them showing also the lower mortality. The chemical composition of the forage was principally influenced by the cut but presented always level judged satisfactory in fibres, lignin and crude proteins (NDF mean of 40%, ADL 8% and CP 19% in mid bloom).

Globally, the good chemical composition of the collection and the excellent behaviour of some varieties justify the cultivation of sainfoin.