Yield and nodulation of Phaseolus vulgaris and the competitivity of an introduced Rhizobium strain: Effects of lime, mulch and repeated cropping

• Published in: Soil biology & biochemistry 1987, Vol.19 (2), p.171-177
• Main Authors: Lucrecia, Maria, Ramos, G., Boddey, Robert M.
• Format: Article
• Language: English
• Subjects: acid soils; Agronomy. Soil science and plant productions; Biological and medical sciences; calcium oxide; continuous cropping; crop yield; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; liming; microbial activity; mulches; nodulation; Phaseolus vulgaris; Rhizobium leguminosarum; Rhizobium leguminosarum phaseoli; soil biology; soil temperature; Soil-plant relationships. Soil fertility. Fertilization. Amendments
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/0038-0717(87)90078-2

Phaseolus vulgaris beans were planted in the field on an acid soil (pH 5.3) to investigate the effects of lime and mulch on nodulation and yield of the plants, and the competitivity for nodule occupancy of an introduced strain of Rhizobium (R. leguminosarum biovar phaseoli). The plots were planted 5 times during a 2 yr period and at the first planting the seeds were inoculated with a peat based inoculum of strain C0405. At subsequent plantings the seeds were inoculated with macerated nodules taken from plants from the previous crop from the same lime-mulch treatment. At the final planting each plot was sub-divided and inoculated either with the original CO5 strain, an acclimatized CO5 strain (isolated from the 4th crop and identified as CO5 using immunodiffusion), or with macerated nodules as before. Throughout the experiment there were no significant effects of any inoculum on nodulation or yield of the bean plants. This was probably due to the low competitivity of the introduced strain which occupied at maximum 31% of the nodules in the unlimed plots and less than 19% in the limed plots. In general mulch had a negative effect on nodulation and yield although at the third crop (March 1983) when soil temperatures were high at the early stages of plant growth, mulch improved germination and the survival At of the seedlings such that pod yield was more than 3 times greater than in unmulched plots. the final crop CO5 occupied at maximum only 24% of the nodules in the unlimed plots and a far lower proportion (0–2%) in the limed plots. The acclimatized strain showed a consistent tendency (statistically insignificant) to be more competitive for nodules sites than the original CO5 strain.