Response of field-grown bean (Phaseolus vulgaris L.) to Rhizobium inoculation and nitrogen fertilization in two Cerrados soils

• Published in: Biology and fertility of soils Vol. 32; no. 3; pp. 228 - 233
• Main Authors: VARGAS, Milton A. T, MENDES, Ieda C, HUNGRIA, Mariangela
• Format: Journal Article
• Language: English
• Published: Berlin Springer 2000
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Biotechnology; Brazil; Economic plant physiology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Nitrogen fertilization; Nitrogen, phosphorus, potassium fertilizations; Phaseolus vulgaris; Rhizobium; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); South America; Brazil; America; Natural population; Nitrogen fertilization; Competitivity; Cultivated soil; Inorganic element; Field experiment; Tropical soil; Mineral fertilization; Dicotyledones; Bacterial inoculation; Angiospermae; Nitrogen fixation; Bacteria; Inoculant; Diazotrophy; Nitrogen fertilizer; Symbiosis; Rhizobium leguminosarum bv. phaseoli; Symbionte; Microorganism interrelationships; Savannah; Vegetal microorganism relation; Nodulation; Rhizobium; Nitrogen; Bacteriology; Strain; Grain legume; Biological fixation; Leguminosae; Vegetable crop; Phaseolus vulgaris; Spermatophyta; Rhizobiaceae; Soil plant relation; Autochtonous; Cerrado
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/s003740000240

Most soils sown with field beans (Phaseolus vulgaris L.) contain indigenous rhizobia which might interfere with the establishment of inoculated strains. As a consequence, the benefits of bean inoculation are usually questioned, and the use of N fertilizer is gradually becoming a common practice. The present study had the objective of evaluating the effectiveness of inoculation and N fertilization in field soil with (site 1) and without (site 2) a previous bean-cropping history. At site 1, which had a rhizobial population of 7x10 super(2) cells g super(-1) soil, inoculation had no effect on nodulation or yield, whereas at site 2 (<10 cells g super(-1) soil) inoculation increased nodulation, nodule occupancy by the inoculated strain and grain yield. N fertilizer decreased nodulation at both sites, but increased grain yield at site 1 but not at site 2, indicating that the response to inoculation and N fertilization depends on the cropping history. When bean was cultivated for the first time, indigenous populations of rhizobia were low and high yields were accomplished solely with seed inoculation, with no further response to N fertilizer. In contrast, previous cultivation of bean increases soil rhizobia, preventing nodule formation by inoculated strains, and N fertilizer may be necessary for maximum yields. A significant interaction effect between N fertilizer and inoculation was detected for serogroup distribution only at site 2, with N fertilizer decreasing nodule occupancy by the inoculated strain and increasing the occurrence of indigenous strains. Consequently, although no benefits were obtained by the combination of inoculation and N fertilizer, this practice may be feasible with the selection of appropriate N-tolerant strains from the indigenous rhizobial population.