Impact of seed burial depth on the emergence and growth of annual forage legumes

The importance of evaluating the tolerance of forages to deeper seed burial is often overlooked. Therefore, this study evaluated the effects of increased seed burial depth on the emergence, vigour and early seedling growth of annual forage legume cultivars in the genera Medicago and Trifolium. A randomised pot trial was conducted where seeds were sown in 20 cm pots at five burial depths and the emergence thereafter was recorded daily for 28 days. Increased burial depth resulted in reduced establishment, vigour and seedling growth. Seed size was positively correlated with establishment from increased seed burial depths, and all vigour indices were negatively correlated with burial depth. The present study showed that seeds with a 1 000-seed mass of ≤2 g should only be planted to a depth of 1 cm, whereas the other seeds could be planted to a depth of up to 3 cm.