Abstract: Plant affects micro-ecological characteristics of rhizosphere. The nutrients (N, P, K, Ca, Mg, Fe, Mn, Zn and Cu) uptake and its distribution across rhizosphere at seedling stage in two soybean genotypes were investigated by rhizobox method. The results showed that the uptakes of N, P, K, Ca, Mg, Mn, Zn and Cu in a high yielding genotype, i.e. Beifeng 11, were higher than that in a low yielding genotype, i.e. Hai 9731, and the greater absorptions of N、P、Ca and Mg per root length and per root surface area were found in Beifeng 11, which indicated that Beifeng 11 had a relatively high root activity. The distribution characteristics of nutrients across rhizosphere were different. The soluble N and Mn concentration within 0~4 mm of rhizosphere was higher than bulk soil (>10 mm), whereas a negative trend was found for the P, K, Mg and Cu. The difference of nutrient concentration in rhizosphere between the two genotypes was obvious. The nutrients in the central compartment and the near zone for Beifeng 11 were higher than Hai 9731, except for K and Fe. Beifeng 11 had lower pH within 0~6 mm of rhizosphere.

Key words: Soybean, Central compartment, Bulk soil, Nutrient distribution, pH in rhizosphere