Growth, water relations and biomass production of the savanna grassesChloris roxburghianaandCenchrus ciliarisin Kenya

A study was carried out to determine and compare the ecophysiology of the perennial savanna graminoidsChloris roxburghianaandCenchrus ciliarisin a semi-arid pediment region of northern Kenya. Growth, phenology, water relations and biomass production potential were investigated under clipped and non-clipped conditions.Chloris roxburghianarecorded faster growth rates and greater dry matter fixation thanC. ciliaris. This study demonstrated possibilities of fodder production of up to 11 t ha−1and 6•6 t ha−1forC. roxburghianaandC. ciliaris, respectively. Similarly,C. roxburghianawas more efficient at controlling water loss thanC. ciliaris, indicating a better adaptation to drought. On average, growth and leaf area development on clipped plots was faster than the controls. However, defoliation delayed and reduced reproduction. Although defoliation improved the water status ofC. roxburghiana, it had no apparent effect on that ofC. ciliaris. Growth and green-up responses ofC. roxburghianaoccurred 2–4 days following rains. The productivity and ecophysiology of these species render them suitable for increasing land productivity in semi-arid areas.