Congo grass is a summer growing species yielding large amounts of biomass with high N supply. DM yield exceeded 20 t/ha in Australia and South America, and up to 25 t DM/ha in Sri Lanka when 366 kg N/ha fertilizer were applied (Husson et al., 2008; Cook et al., 2005). In the low fertile soils of Coronel Pacheco (Brazil) with no N fertilizer, Congo grass yielded only 6 t DM/ha. However, biomass yields up to 12 t DM/ha were possible after applying 150 kg/ha N fertilizer (Cook et al., 2005). Biomass production is at its highest during the second year of establishment. Congo grass is markedly less productive than signal grass, which reduces its potential as a forage crop, particularly in low-fertile soils (Schultze-Kraft et al., 1992).
Congo grass can be propagated both from root stock and from seeds (Urio et al., 1988). If propagation by seeds is intended, the dormancy of the seeds will be broken after 6 month storage, or by chemical scarification. Seeds can be broadcast on a well-prepared seedbed and should not be planted deeper than 2 cm. The vigour of Congo grass seedlings is high and prevents weed development (Husson et al., 2008). If Congo grass is vegetatively propagated, stem cuttings with rooting nodes are necessary. As Congo grass requires good soil fertility, it is important to provide N, P and K fertilizers prior to planting and during growth (Cook et al., 2005). Once it is established, and provided it receives enough N fertilizer, Congo grass spreads readily. Congo grass flowers later than signal grass (Schultze-Kraft et al., 1992). It should be cut before first flowering and then at six week intervals (ILRI, 2013). When grazed, Congo grass withstands limited heavy grazing (Cook et al., 2005).
Association with legumes
Congo grass can be grown in association with a wide range of legumes such as stylo (Stylosanthes guianensis), puero (Pueraria phaseoloides), greenleaf desmodium (Desmodium intortum), centro (Centrosema molle) and leucaena (Leucaena leucocephala). In mixed swards Congo grass should be heavily grazed so that the sward becomes open and allows legumes to establish and persist (Cook et al., 2005). When grown in association with stylo, both plants can be harvested together to make good quality silage (FAO, 2015). It is possible to make pure Congo grass silage with formic acid as an additive, the best quality being obtained with 2 L formic acid/t (Lowilai et al., 2002).