Effect of Low Molecular Weight Organic Acids on Root Morphology and Phosphorus Accumulation in Soybean

Most of the farmlands in the world are lack of phosphorus,organic acids exudates from plant root increase under phosphorus deficiency,the plants form several adaptability mechanisms to adapt the phosphorus deficiency environment.In this study,three low molecular weight organic acids(citric acid,oxalic acid,malic acid and their mixture)were selected to study the effect on root morphology and phosphorus accumulation in soybean by sand culture experiment,the results showed that soybean root biomass,root to shoot ratio,root length,root surface area and root volume all significantly decreased under different low molecular organic acids treatments compared with control,and the inhabitation enhanced with the concentration increasing,suggested that the low molecular weight organic acids restrained the growth of soybean,and made the competition of soybean root decreased.Meanwhile the efficiency of phosphorus absorption decreased significantly while the efficiency of phosphorus utilization increased under the low molecular weight organic acids treatment compared with control.