The Effect Of Co-inoculation Of Peanut Bradyrhizobium And Molybdate And VA Mycorrhiza On Acid Purple Soil

Aiming at Mo, B, P deficient acid purple soil from main peanut cultivated areas in Sichuan, and VA mycorrhiza high effective accepting P ability, We developed a new type of inoculant by putting peanut bradyrhizobial strain and trace element Mo,B together, and made scientific researchs on the effect of combined application of above new type of inoculant and VA. The results are as following:The result indicated that the two tested strains spr4-5 and spr2-9 had more Mo tolerance ability than B. According to the two tested strains tolerance of Mo, B, we developed a new type of inoculant by putting peanut bradyrhizobial strain and trace element Mo, B together. The combined inoculantion with ammonium molybdate had high viable rhizobial number which increased with the increase of ammonium molybdate concentration. The combined inoculantion with boracic acid or with ammonium molybdate and boracic acid had low viable rhizobial number. The above results indicated that peanut bradyrhizobial strain didn't fit to combine with B, but fitted to combine with Mo.Ammonium molybdate is more suitable in combination with rhizobia than the natrium molybdate. The combined inoculant with ammonium molybdate had more viable rhizobial number than that of using natrium molybdate. The pH value of the combined inoculant increased with the increase of molybdate concentration, also with incubation time prolonging. The pH value of the combined inoculant with natrium molybdate increased more significantly than that of using ammonium molybdate. Within 180 days incubation time, the pH value and viable number of the combined inoculant with ammonium molybdate reached the quality requirement of Rhizobial Fertilizer Standard. Natrium molybdate is not suitable to be added into rhizobial inoculant, because of the low viable number and the pH value change. In order to detecting the tested trains competitive ability with soil indigenous rhizobia in subsequent pot experiment, the two tested strains were labeled with gusA gene.The pot experiment results were as followed : (1) The tested strains showed different symbiotic effectiveness at different concentration of ammonium molybdate. Spr4-5 was more effective when the concentration of ammonium molybdate was 0.2%. The yield increased by 73.4%, 13.7% compared with CK and traditionalinoculant, respectively, and the rate of nodule occupancy was 59.7%. Spr2-9 was more effective when the concentration of ammonium molybdate was 0.3%. The yield increased by 49.0%, 21.4% compared with CK and traditional inoculant, respectively, and the rate of nodule occupancy was 70.3%. The increased yield reached significant level. (2) The effect of co-inoculation of VA mycorrhiza and the combined incolants with Spr4-5 and Ammonium molybdate indicated that the effect of double inoculation with traditional inoculant and VA mycorrhiza was the best. The yield increased by 3.8%, 14.28%, 58.25% compared with traditional inoculant, VA mycorrhiza and CK, respectively. VA mycorrhiza had high effective ability of absorbing phosphorus and strong adaptability of new circumstances. But the effect of double inoculation with VA mycorrhiza and the combined inoculants with Spr4-5 and Ammonium molybdate showed negative effect on the yield. The yield decreased. The decreased yield reached significant level. The result indicated that Glomus mosseae was sensitive with Mo.