GRASSLAND IMPROVEMENT IN SUBTROPICAL GUANGDONG PROVINCE, CHINA .2. EVALUATION OF PASTURE GRASSES

During 1986-1989, 3 experiments evaluated the role of tropical and temperature grasses in improving subtropical grassland in China: (1) spring- and autumn-sown tropical and temperature grasses; (2) spring-sown tropical grasses on limed and unlimed Hapludult soils; and (3) response of 2 temperate grasses (perennial ryegrass and cocksfoot) to rates of lime in pots. The tropical grasses were more tolerant of acid soils than temperate species, but only low-quality grasses (e.g. molasses, plicatulum) grew well when fertilised only with superphosphate (300 kg/ha). Applying PK or NPK fertiliser at sowing increased the range of grass species which established successfully and doubled the yield of those grasses which established with P fertiliser only. Molasses grass, setaria, signal grass and guinea grass all produced more than 4800 kg/ha with moderate NPK inputs. Liming (4 t/ha) also increased yield of 9 tropical-subtropical grasses (including rhodes, buffel, signal, guinea and green panic) and perennial ryegrass, but significantly reduced yield of molasses and carpet grasses. Pioneer grasses may be of value for initial soil improvement, but spring- or autumn-sown setaria is recommended as the base grass for improved pastures with and without lime in subtropical Guangdong Province with moderate application of PK fertiliser. Lime application with high fertiliser inputs is essential for the production of temperature grasses and winter forage crops.