ORGANIC VERSUS SYNTHETIC FERTILISATION OF BEANS (PHASEOLUS VULGARIS L.) IN MEXICO

Phaseolus vulgaris is considered an inefficient nitrogen fixer, and therefore farmers in Mexico use large quantities of synthetic nitrogen fertilisers. The aim of this research was to evaluate the performance of native isolates of Rhizobium spp. and Bacillus spp. as biological fertilisers in northern Mexico. A first test was carried out under greenhouse conditions to analyse 15 native isolates of Rhizobium and 15 native isolates of Bacillus. Based on their effects on the bean crop, the best treatments were tested under field conditions. In the field, the combination of Rhizobium and Bacillus (Rz + Bs) produced the highest grain yield, biomass production, number of nodules per plant and dry weight of nodules, statistically surpassing (p ≤ 0.05) the control (without inoculation and fertilisation). Furthermore, compared with synthetic fertilisation, no statistical differences were found, which suggests that the combination Rz + Bs can replace synthetic fertilisation.