Effect of Potassium and Legumes on Establishment and Growth of Pasture Mixes in the Mid-Country of Sri Lanka

Experiments were conducted at 2 locations where guinea 'A' (Panicum maximum) was grown in monoculture and with 3 legumes, stylosanthes (Sty/osartthes hamata), centrosema (Centrosema pubescenes) and siratro (Macroptilium atropurpureum) at four levels of potassium (K) (0, 30, 60 and 90 kg K.iO/ha/yr). Leaves/plan! and height of grass were recorded weekly for 5 weeks after planting; dry matter (DM) yield, total nitrogen (N) and minerals were measured monthly for both grass and legumes. Application of K did not have any significant effect on the height, leaves/plant, DM yield, N and mineral content of forages. However, application of K increased (P<0.05) lhc K content of tJ1c grass and legumes at one site (Meewathura). Inclusion of legumes increased (P<0.05) the total DM yield and K content of the associated grass. Height and leaves/plant of the grass was lowest with stylosanthes, indicating a competitive effect by this legume.