Effects of dairy manure compost and supplemental inorganic fertilizer on coastal bermudagrass

Management strategies for using raw and composted dairy manures on perennial forages are not well defined. `Ihis study compared the effects of raw or composted dairy manure alone, or in combination with supplemental inorganic fertilizers (IFs), on 'Coastal'bermudagrass Icynodondactylon (L.) Pets.] yield. Composted manure was split applied with 14.5 Mgha(-1) in 2002 and 2003 for a total of 29Mgha(-1) (CI), or single applications of raw dairy manure (M) at 54Mghaa(-1) or composted manure at 29 (C2) or 58 (C3)Mgha-I were applied in 2002.fhese treatments were compared with an IF check (112kgNha(-1) cutting(-1) plus 49kgP ha(-1) yr-1 plus 93 kg K ha(-1) cutting(-1)) and an untreated check (UQ. Selected compost and manure plots also received supplemental inorganic N at rates of 0, 56, 84, and 112 kg ha(-1) cuttinga(-1), or 112 kg N ha(-1) cutting(-1) plus inorganic P (49 kg P ha(-1) yr(-1)) or K (93 kg K ha(-1) cutting-). Maximum yields were obtained with 56 kg N ha-1 cutting-' in 2002, and with 84 kg N ha(-1) cutting' in 2003 and 2004. In 2004, supplemental inorganic P increased forage yields with the lower rate of compost (C2), and supplemental inorganic K increased forage yields of C2 and M treatments compared with the compost or M treatments alone.