Abstract

Isolating Azospirillum bacterium from soil and root of rice in field (Vinh An town - Dong Nai province, Thu Duc – Ho Chi Minh city). The 4 strains are collected. Among them there are A, and A4 strain fixing nitrogen strongly, respectively 128 mg/l và 136mg/. Studying some characteristics of Aj and A4 for preliminarily making biofertilization product by immobilizing them on the substrate (alginat, peat) and their effect on germinative seeds to rice sprouts in the laboratory conditions. The results show the control samples (no supporting the biofertilization) have length of leaves and roots are 27.60 cm and 7.25 cm respectively. Whereas the experimental samples support: + With the biofertilization product containing alginat substrate, the Aj strain has length of leaves: 30.40 cm, A4 strain: 33.60 cm; and length of roots in order of 8.46 and 8.30 cm, respectively. + With the biofertilization product containing peat substrate, the Aj strain has length of leaves: 37.60 cm, A4 strain: 36.90 cm; and length of roots in order of 7.30 and 9.60 cm. Beside, they have dark green leaves, wide leaf-blades, high haulms, a lot of roots, higher dry weight, more outshooting, bigger and harder haulms.