Effects Of Inoculation With Rhizobium And Phosphate On Growth Of Vetch

As a high quality forage and green manure crop, spring vetch (Vicia sativa) plays an important role in adjusting agricultural planting structure, grassland animal husbandry development and soil fertility improvement. Using a combination of greenhouse and field experiments, present study explored the effects of rhizobia inoculation and phosphate fertilizer on plant growth and production of three cultivars ("Lanjian 1" "Lanjian 2" and "Lanjian 3") of V. sativa, the main results are as following;1. Inoculation with three rhizobia strains (CCBAU01085, CCBAU01069, J3) significantly promoted root nodulation and seedling growth of vetch in the greenhouse conditions. Compared to control, rhizobia inoculation respectively increased nodule number, weight and nitrogenase activity by 9.2 to 17.5,0.11 to 0.25, and 39.8 to 55.2. Meanwhile, the total nitrogen content, seedling height and root length were increased by 36.3% to 74.0%,15.3% to 43.8% and 17.4% to 45.5%, respectively. Based on the symbionts performance in the greenhouse, strain CCBAU01069 matched the best with tested cultivars, and thus selected to use in the field test.2. Inoculation significantly increased the yield of hay and seed, crude protein content and P content of spring vetch as well as plant growth under field conditions. Compared with the control, inoculation increased the average plant height, hay production, seed yield, plant crude protein and P content of three spring Vetch cultivars by 23.8%,31.8%,23.6%,27.9% and 9.2% respectively. Meanwhile, the total soil nitrogen and organic matter were increased by 33.0% and 17.3%, but the total soil phosphorus and available phosphorus showed no change after inoculation with rhizobia.3. Phosphate (750kg/hm2,12% P) significantly improved the growth of Vetch and soil fertility. Compared to the control, P fertilization respectively increased the average plant height, hay yield, seed yield, plant crude protein content and P content of three spring Vetch cultivars by 19.8%,26.7%,13.2%,15.1% and 21.5%. Meanwhile, total soil nitrogen, organic matter, total soil phosphorus and available phosphorus content were increased by 18.7%,10.1%,21.1% and 18.8% after P fertilization, respectively.4. Combined treatment with rhizobia inoculation and P fertilizer significantly increased the average plant height, hay yield, plant crude protein and P content by 44.0%,59.8%,42.8% and 38.7%, respectively. However, seed yield was significantly decreased by 11.4% after the combined treatment. In contrast with this, soil organic matter, total nitrogen, total phosphorus and available phosphorus content were increased by 53.0%, 30.2%,43.1% and 27.4% after combined treatment, respectively.5. In summary, hay yield from high to low in order for combining rhizobia inoculation with phosphate fertilizer treatment> single rhizobia inoculation treatments single application of P fertilizer; the order of seed yield for single inoculation treatment> single phosphate fertilizer treatment> the combined treatment.