Effect of Cu contamination on microorganisms in rhizosphere of RumexK-1

Abstract

Effects of Cu contamination on microorganisms in rhizosphere of RumexK-1 were studied. The results showed that the numbers of fungi, phosphate-solubilizing bacteria and potassium-solubilizing bacteria all increased at low copper concentration but decreased at high concentration. The numbers of bacteria, actinomycetes and ammonibacteria of those copper additions were all lower than that of control. Soil respiration increased under copper treatment except at 300 mg kg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> copper concentration, and the highest soil respiration was observed at 100 mg kg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> treatment, about 38.38 mg (g d) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . Soil microbial biomass nitrogen (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mic</sub> ) of copper treatment was lower than control except 50 mg kg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> treatment. The highest N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mic</sub> was observed at 50 mg kg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> treatment, about two times of CK, while the lowest was at 300 mg kg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , only 1/6 of CK.