Effects of some animal manure and rate of application on growth, herbage and seed yields of Rhodes grass (Chloris gayana var. Callide)

Abstract

Introduction Forage grasses such as Chloris gayana depend on the soil for mineral nutrients which promote their growth, whereas ruminants rely on grasses for much of the energy and minerals they require for maintenance and reproduction. Inadequate fertilizer application reduces the herbage yields and quality of pasture grasses (Humphrey, 1987) with negative impact on ruminant nutrition. Proper fertilizer application to grasses could sustain the interdependency of grasses and ruminants in a fragile pasture-animal eco-system (M.S. Kallah, personal communication). Chloris gayana is popular and widely cultivated in Kenya as a forage crop. In the ra iny season , the c rude pro te in concentration of Rhodes grass exceeded 11.1 % while its crude fibre (CF) concentration (21.1 %) was lower than that of signal grass (23.4 %), pangola grass (25.3 %) and kikuyu grass (39.9 %) based on an evaluation at Vom. Digestible crude protein and metabolic energy of Rhodes grass was adequate for the maintenance and growth of sheep (Kevelenge et al., 1999). The crop exhibits high seed and dry matter (DM) yields, good sward persistence, high pure germinating seed (PGS) content and is Abstract An experiment was conducted twice concurrently at Vom in Plateau State Nigeria in 2011 to evaluate the effects of three animal based organic fertilizers and three rates of application on the growth, seed and herbage yields of Rhodes grass (Chloris gayana var. Callide). This study involved three types (poultry, rabbit and sheep dung) of animal fertilizer and three rates (0, 25 -1 and 50 t ha ) of application in a 3 x 3 factorial arrangement fitted into randomized complete block design and replicated three times. Animal fertilizers significantly (p < 0.05) increased growth, seed, fresh herbage and dry matter yields of Rhodes grass. Generally, fertilizers from poultry and rabbit were similar and better (p < 0.05) than that of sheep in the enhancement of the measured variables. At 6 weeks after fertilizer application (WAF), fresh herbage yield was -1 -1 in the range of 14.6 – 48.3 t ha whereas dry matter yield ranged from 4.7 – 13.9 t ha while -1 seed yield was 1.8 – 2.3 t ha . At 12 WAF, rabbit fertilizer produced significantly higher values than sheep fertilizer by 21.2 % for sward height, 70.1 % for fresh herbage yield and 61.4 % for dry matter yield. The correlation coefficients among the measured variables were positive and highly significant. The highest correlation recorded (0.937**) was between fresh herbage and dry matter yields. The study indicated that application of either rabbit or poultry fertilizer can suitably enhance Rhodes grass growth for higher herbage and seed yields. The -1 study also showed that 25 and 50 t ha of animal fertilizers on Rhodes grass yielded similar results. With adequate fertilizer application, Rhodes grass can produce sufficient herbage to meet the nutritional requirement of several ruminant livestock. It is not economical to apply -1 more than 25 t ha of animal fertilizers to Rhodes grass if they contain more than 1.21 % of nitrogen.