Increasing of NPK Fertilizer Efficiency by Arbuscular Mycorrhiza in Common Bean ( Phaseolus Vulgaris L.)

Tropical soils are mostly poor in phosphorus and sometimes in nitrogen and potassium. Arbuscular mycorrhizae increase the efficiency of chemical fertilizers applied to crops, and this work is part of this framework. NPK (nitrogen-phosphorus-potassium) was applied at 100 kg per ha and 200 kg per ha alone or in combination with inoculum from sorghum or leek in soil (pH 4.28). The trial was conducted on a 3 × 3 split-plot design with 3 replicates. Plant height, number of leaves and chlorophyll level in the leaves were evaluated. The frequency of root colonization by mycorrhizal fungi was also studied. The number of pods per plant, the number of seeds per pod and the yield were also evaluated. The results showed that vegetative parameters increased with the addition of fertilizers while production parameters varied little with fertilizers but significantly, when these fertilizers were associated with mycorrhizal inoculum. Treatments with 200 kg NPK combined with sorghum inoculum produced 512 kg of beans per ha, while 200 kg NPK alone produced 278 kg of beans per ha.