Response of setaria (Setaria sphacelata) to phosphorus and potassium on red soils in subtropical China

Abstract

The response of pastures to low inputs of P and K fertilisers at Lechang Model Cattle Farm in north Guangdong Province was undertaken because of the widespread phosphorus and potassium deficiency of hapludult soils in grasslands regions of subtropical China. Setaria sphacelata (cv Kazungula) was sown in a factorial plot experiment with P (0 and 37 kg P ha−1) and K (0 and 50 kg K ha−1) treatments. Effects of fertilisers on soil chemistry, pasture yield and nutrient contents of foliage were monitored between 1986 and 1988. Applied P increased pasture yield during the first summer, but had no effect thereafter. In contrast, K fertiliser doubled available soil K and had an effect on setaria yield at all measurements although the effect diminished with time. The practical implications of these results are discussed in relation the future of pasture development on acid soils in south China.