4STOOP W A,UPHOFF N,KASSAM A. A review of agricultural research issues raised by the system of rice intensification (SPI)from Mada gascar:Opportunities for improving farming systems for resource-poor farmers[J].Agric Systems,2002,(03):249-274.
5AKITA K,TANAKA N. Effects of planting density and planting patterns of young seedlings transplanting on the growth and yield of rice plants[J].Japanese Journal of Crop Science,1992,(01):80-86.