Improving grain yield and nitrogen fixation of common bean grown in an acrisol from Cuba

Field experiments were carried out to evaluate the effect of selected management practices such as the use of phosphate rock (PR), partially acidulated phosphate rocks (PAPRs) and soil liming, on improving grain yields and biological nitrogen fixation (BNF) of common bean (Phaseolus vulgaris) grown in an strongly acid Acrisol from Cuba. In Experiment 1 the agronomic effectiveness of the indigenous Trinidad de Guedes PR and FPA 50, a PAPR from Trinidad de Guedes PR with H2SO4 at 50% acidulation level were evaluated as P sources for the common bean genotypes, BAT 477, DOR 364, DOR 390 and Censa. In Experiment 2 the response of the CC 25-9N common bean genotype to the increasing application rates (40, 80 and 120 kg P2O5 ha-1) of two P sources, i.e. triple super phosphate and C 40, was determined at two liming levels. C40 was a PAPR from the indigenous Trinidad de Guedes PR with H2SO4 at 40% acidulation level. In Experiment 3 the effect of soil liming on grain yield and BNF of BAT 58, BAT 304, BAT 477, DOR 364, DOR 390, Judia Roja Camagueyana (JRC) and Censa common bean genotypes was studied. The most effective P sources to increase grain yields of the studied bean genotypes were the water-soluble superphosphate in experiments 1 and 2. Both partially acidulated PR products, FPA 50 and C 40, showed intermediate agronomic effectiveness and they increased grain yields over the PR and control (without P) treatments. Soil liming increased grain yields and BNF of the common bean genotypes tested. Based on an economic analysis of profit and value/cost ratios, single superphosphate was the P source that gave the highest economic profit for all common bena genotypes while FPA 50 was efficient for DOR 390 and Censa. Lime application increased the economic profit of all bean genotypes. Genotype BAT 304 showed adaptability to soil acidity and gave the highest profit in limed soil. (author)