A 47% increase in net yield can be achieved by increasing the number of species in temporary grassland, according to Ian Wilkinson, Managing Director of Cotswold Seeds Ltd, a speaker at the June Pollinator. Extensive trials across Europe have revealed that forage legumes grown in a ley can increase the nutrient value of the sward, fix nitrogen to give an uplift to subsequent crops and provide invaluable food and shelter for insect pollinators.
Wilkinson says: “Wildflower meadows have declined significantly since the 1950s and over the same period we have also seen a decline in bee numbers.”
Wilkinson sees that increasing diversity in temporary grassland, or leys, can provide benefits on a number of levels. “Cultivated legumes such as peas and beans are excellent within a rotation as through nitrogen fixation they can increase the fertility of the soil. We are recommending that these same benefits can be achieved with wild species of forage legumes, such as clover, lucerne, trefoils and vetches grown within a mix of grass species and herbs.
“Another advantage is that a mix of species providing ground cover and flowering through the year protects the soil, reduces runoff and provides food and shelter for insects who may spend part of their lifecycle in the ground.”
Ian Wilkinson joined Lydia Smith, Head of Innovation Farm NIAB; Beverley Glover, Director of the Cambridge University Botanic Garden; Lin Field of Rothamsted Research and Lynn Dicks, Department of Zoology, University of Cambridge to discuss how pollinators can be increased in a productive farm.