THE INFLUENCE OF Rhizobium INOCULATION AND NITROGEN/MOLYBDENUM FERTILIZATION ON THE GROWTH CHARACTERISTICS OF RED CLOVER

摘要

This paper presents the individual and combined effects of inoculation and nitrogen (N)/molybdenum (Mo) fertilization(8 treatments) on the biological efficiency of red clover in controlled conditions. The rationale of the study was toestablish the influence of Mo on the biological efficiency of red clover in the presence or the absence of N fertilizationand inoculation of Rhizobium leguminosarum biovar. trifolii, and whether the results can lead to the improvement ofclassical crop technologies and the fertilization plan for obtaining superior forage yields. The effects of the treatmentswere evaluated using 5 replicatesbased on the average height, the dry weight, the density and the number of nodules onthe roots of the red clover plants. Diploid cultivar Violettawas seeded in vegetation pots with the same amount of seedsand maintained 60 days in controlled conditions of a growth chamber. In the inoculation variants (5-8), the seeds werebacterized with R. trifolii-treated strains using the Nitragin? product (B type) using 7.5 g Nitragin/kg clover seed,dissolved in about 25 mL cold water. After pre-homogenization of the seed in the resulting solution, it was sown withthe same quantity in all the repetitions of the variants. The bacterial solution contains at least 100 million viablecells g-1 of R. trifolii. Nitric fertilization was done with ammonium nitrate (34.5% N) supplied prior to sowing in anequivalent dose of 100 kg N ha-1. Molybdenum (0.02 Mo) was supplied using a uniform foliar spraying with threeapplications. Descending ranking and multiple comparisons (Duncan test) of treatments were performed. The seedinoculation, without nitrogen fertilization provided relatively equivalent biomass yieldsto fertilized variants. Foliarfertilization with molybdenum did not determine higher dry weight amounts, but when combined with nitrogenestablished significant amounts of dry matter per plant. From the yield formation point of view, the variants in which alarge number of nodules were formed did not correlate positively with dry matter accumulation; however, they canhave a particular importance in improving the reserves of assimilable nitrogen available in the soil.