The local isolate Bradyrhizobium manausense efficiency evaluation in the growth of cowpea under different levels of molybdenum in gypsiferous soil.

Gypsiferous soil suffers from several problems, including the low numbers of symbiotic bacteria that fix atmospheric nitrogen, this causes a failure in the formation of root nodes, fixation of atmospheric nitrogen, and poor growth and production of leguminous crops, therefore this study was conducted with the aim of encouraging the formation of root nodes and improving the growth and yield of cowpea plants by using an environmentally friendly, non-chemical biological inoculum, a field experiment was conducted in gypsiferous soils to study the effect of inoculation with prepared inoculum from Bradyrhizobium manausense in the growth of cowpea under different levels of molybdenum, the results showed that the effect of inoculation with prepared inoculum of Bradyrhizobium manausense was significant in the weight of the vegetative part, the weight of the dry root part, the concentration of molybdenum and nitrogen for the shoots in the flowering stage, compared to the uninoculated treatments. The results showed that the fertilization with molybdenum at the level of 2 kg Mo ha−1 was significantly superior to all treatments fertilized with molybdenum in vegetative and root dry weight, and concentration of molybdenum and nitrogen in the vegetative part in the flowering stage. The treatment inoculated with Bradyrhizobium manausense and fertilized with molybdenum at the level of 2 kg ha−1 gave the highest values in the weight of the dry vegetative and root part and nitrogen concentration, while the inoculated and fertilized treatment at the level 4 kg ha−1 molybdenum significantly increased the molybdenum content in the vegetative part. [ABSTRACT FROM AUTHOR]