Effects of rhizobium, arbuscular mycorrhiza and lime on nodulation, growth and nutrient uptake of lucerne in acid purplish soil in China

Abstract

The effects of inoculation with rhizobium (Sinorhizobium meliloti) and arbuscular mycorrhizal fungus (Glomus intraradices) and lime application on growth, nodulation and nutrient uptake of lucerne on an acid purplish soil (Udorthent) were investigated in a greenhouse pot experiment. Seedling roots were inoculated with liquid S. meliloti inoculant at transplanting, and arbuscular mycorrhizal inoculum was applied to soil in pots before sowing. In the limed treatment, lime was added to adjust soil pH from 5.45 to 6.54. Plants were harvested 2 months after inoculation. Both application of lime and inoculation with mycorrhiza increased nodule numbers and total nodule weight (P<0.05) over that with rhizobium alone. This was reflected in increased top growth and top + root growth in plants receiving both lime and mycorrhiza (P<0.05). Inoculation with mycorrhiza or rhizobium or lime application tended to improve concentrations of phosphorus and nitrogen in top growth compared with uninoculated plants. Inoculating lucerne with rhizobium and mycorrhiza on these acid soils should improve plant growth but this needs to be verified by field trials.