A plant of the moister tropics. It prefers an annual rainfall of 1,500 mm or more but plants have persisted in pastures receiving an average annual rainfall of only 800 mm[310 ]. It can survive a 3 - 4 month dry season but is not adapted to prolonged drought[310 ]. It is intolerant of low temperatures, growing poorly when they fall below 15?c[310 ]. Tolerant of waterlogged conditions[310 ]. Plants are shade tolerant, and can persist even with shade levels as high as 80%[310 ]. The plant produces large quantities of viable seeds. It has escaped from cultivation and become established in the wild in some areas[305 ]. It forms dense mats of growth on the ground, and also climbs onto trees. It is a vigorous plant that invades disturbed areas, choking out more desirable species - often the tree layer is destroyed and regeneration of native species is prevented[305 ]. Centro is notoriously slow to establish and requires good conditions during the establishment period, but when grown in a pure sward it forms a dense, compact cover 35 - 45 cm deep, 4 - 8 months after sowing. It is fully established and vigorous by at least the 2nd year. In ungrazed mixtures with Panicum maximum, it forms an impenetrable vine canopy some 2 metres high. In a mixture with calopo (Calopogonium mucunoides) and puero (Pueraria phaseoloides), centro persists longest under the closing canopy of plantation crops[310 ]. In the humid tropics, the preferred legumes for fertile and infertile soils have traditionally been centro and stylo (Stylosanthes guianensis) respectively. However, when soil mineral deficiencies are corrected and seed is inoculated with an effective bacteria, centro has been more productive than stylo on all land classes[310 ]. Centro combines well with other species in mixed pastures or ground covers under plantation crops[310 ]. Trailing runners have a tendency to root at the nodes if soil moisture is high, giving the plant a stoloniferous appearance[310 , 415 ]. Pure stands of centro have produced DM yields of up to 12 tonnes per hectare per year[310 ]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[200 ]. Nodulation occurs with a range of rhizobia but optimal growth has been achieved with very few strains. Inoculation with an effective strain of Bradyrhizobium is, therefore, recommended[310 ]. Estimates of nitrogen fixation range from 120 - 270 kg/ha per year[310 ].