Grazing Tolerance of Warm‐Season Legumes in Peninsular Florida

Abstract

AbstractDespite the potential benefits and frequent favorable results in germplasm evaluations, only limited success has been attained in many areas with tropical pasture legumes. Lack of information regarding both germplasm adaptation and pasture management requirements has been a limitation. Five promising perennial species were evaluated for grazing tolerance and response to fall grazing deferment on an Immokalee fine sand (Sandy, siliceous, hyperthermic Arenic Haplaquod) at Ona, FL. Alysicarpus vaginalis DC; Desmanthus virgatus (L.) Willd.; Galactia elliottii Nuttall; G. volubilis (L.) Britton; Vigna adenantha (G. F. Meyer) Marechal, Mascherpa, and Stainier; and the standard ‘Florida’ carpon desmodium [Desmodium heterocarpon (L.) DC] were subjected to three treatments: (i) continuous grazing through the growing season (late May to mid‐December), (ii) continuous grazing with fall deferment (grazed late May to mid‐September), and (iii) an ungrazed control. Legume main plots, 5 by 15 m in a randomized complete block design, were split in a strip‐plot arrangement to give grazing treatment subplots of 5 by 5 m. Legumes were transplanted in 1986, grazed in 1987 and 1988, and evaluated for persistence through the summer of 1989. By December 1988, the prostrate A. vaginalis had the highest (P < 0.05) survival percentage under both grazed treatments. Survival of D. virgatus, G. elliottii, and V. adenantha was generally highest in the ungrazed control. The Galactia species demonstrated superior adaptation to drought during the spring of 1989. Fall deferment consistently increased survival of only G. volubilis and V. adenantha. Tolerance of continuous grazing was suggested only for A. vaginalis and carpon desmodium. Grazing management strategies involving periods of deferment from grazing during the growing season will apparently be necessary for persistence of stands of D. virgatus and G. elliottii.