EFFECT OF DOLOMITE AND SOWING RATE ON PLANT-DENSITY, YIELD AND NUTRITIVE-VALUE OF PASPALUM-ATRATUM

Three experiments were conducted with the perennial pasture grass Pasp alum atratum cv. Suerte at Ona, Florida. In Experiment I, Suerte was e valuated in 1992-1993 on a Pomona fine sand for responses to dolomite (0, 1.1, 2.2; 3.4, 4.5 and 6.7 t/ha) and broadcast-sowing rates (5.6, 13.6 and 20.5 kg/ha pure, live seed [PLS]). Dolomite increased soil pH (4.5 + 0.22X, X = t/ha), Suerte density (plants/m(2) = 32.7 + 7.3X 0. 99X(2)) and mean 42-d forage yield (kg/ha = 2904 + 248.0X - 25.1X(2)). Dolomite did not affect crude protein (6.1%), but did increase IVOMD (% = 53.6 + 0.65X). A target pH for Suerte should be about 5.0, which was achievable with about 3.0 t/ha dolomite on this sandy Florida soil . Initially, density increased with increasing sowing rate (plants/m(2 ) = 18.6 + 1.7X, X >5.6 kg/ha PLS), but there was no difference in den sity after 2.5 years (33 plants/m(2)). In Experiment II, Suerte was br oadcast-sown at 1.5, 3.0, 4.5 and 6.0 kg/ha PLS on March 1, May 1, Jul y 1 and September 1, 1995. Average density in the 84-d period after so wing from March and May increased with increasing sowing rates (plants /m(2) = 11.3 + 2.3X, X = >1.5 kg/ha PLS), whereas July and September s owings failed due to flooded soil. Mean yield in June and July 1996 fr om March and May 1995 sowings increased with increasing sowing rate (k g/ha = 1200 + 240X). When broadcast, seed should be sown at 5-6 kg/ha PLS. In Experiment III, Suerte seed was flooded for 0, 2, 4, 6, 8, 10, 14, 21 and 28 d, drained, and incubated for 28 d. Suerte seed lost ab out 2% germination for each day it was flooded.