Application Of Arbuscular Mycorrhiza On Cleaner Production Of Rice

The non-point source pollution has attracted more and more attention in the whole world along with the global water environment problems increasingly serious. Agricultural pollution as one of the most serious non-point pollutant source made a great contribution to water pollution in the northeast of China. As the most important crop in the world, rice has the most yield and planting area of all the crops. The improvement of the rice yield depended on the extensive use of pesticide and fertilizer, which leads to the agricultural non-point source pollution. Rice likes wet, this characteristic gave rise to the most fearful diffusion of pollutant.In view of the above situation, rice (Oryza sativa L.) was selected as experimental material, and arbuscular mycorrhizal (AM) inoculation technique was applied to the cleaner production of rice. The methods of cheap preparation for arbuscular mycorrhizal fungi (AMF) inoculum and rice-mycorrhiza coupling system construction were studied. Meanwhile, the influences and possible mechanism of different level of AMF infection to rice and matrix were discussed. AM techniques provided guidance for the cleaner production of rice and new direction for the source reduction of agricultural non-point source pollution.Five treatments, including straw, paddy roots, 20%, 50% and 80% intensity of nutrition, were utilized in the preparation of AMF inoculum. AMF infection rate were analyzed on the 20th, 40th and 60th day of sorghum growth. Results showed that in the actual production the straw strength measure had high infection rate and low cost. While, AMF infection rate was much higher than others under the 20% intensity of nutrition. Much more, the difference of wet absorption water content and pH value of substrate within the two treatment were not obvious, which ensured the ecological safety of AMF inoculum.In rice-mycorrhiza coupling system construction, the difference of mycorrhizal formation from two types of inoculation was not significant. But transplant inoculation was more suitable for the facilitate simulation and comparison for the production practice. AMF infection rate, stem length, leaf area and the rate of ear were detected in five planting density and the interval 1150 strains of every square meter to 1650 strains of every square meter was the best planting density in pot experiment. Based on the analysis of development status of AMF and rice, the physical and chemical properties of matrix was inoculated 5 effective inoculation doses of inoculum, 130 g of every basin was considered as the best effective dose of inoculum. In mycorrhizal effect validation tests, compared with natural matrix conditions, AMF infection rate was improved 68 % by artificial inoculation. The stem length, total biomass, total surface area of root and yield of rice were increased by 20.6%, 30%, 36.6% and 45.3% respectively. While artificial inoculation not only increased the photosynthet ic capacity but also reduced the blade respiratory rate of rice. The effects of artificial inoculation on moisture absorption water content, pH value, the numbers of bacteria and actinomycete were all not significant. In addition, organic matter, available nitrogen, available phosphorus and available potassium of matrix increased by 24.9%, 13.7%, 14.8% and 15.1%, respectively, by artificial inoculation.