Study On Effect Of Rice Straw Allelochemicals To Rice Growth And Eliminate The Impact Of Allelopathic

Allelopathy widespread in nature,which is produced by a living plant. The living plant release certain chemicals to the environment through volatilization, leaching, secretion, and decomposition, etc., which affect the environment or other plant growth and development of chemical ecology phenomenon. Rice is strengthen the sense of the role of plants, Allelochemicals are released by rice straw through the rain leaching and decomposing,which produce adverse effects on next season crops. In recent years, Use of rice allelopathic inhibit the barnyard grass, weed growth in paddy fields and the development of pollution-free green allelopathic herbicides become a hot research. Rice allelopathy could inhibit weed also could inhibit crops. The study found that the rice straw were covered on the wheat fields could have a good influence. However, previous studies only focused on the benefits of Straw returning, few researchers pay attention to the allelopathy of rice straw. This paper focuses on the allelopathic autotoxicity of rice straw, isolation and identification of the rice straw extract allelochemicals and the microbiological method to eliminate the allelopathy. The results are as follows:1.Effect of Rice seed germination,seedling growth,physiological and biochemical indicators with Different concentrations of rice straw extractStudy on rice straw extract autotoxicity through Biological methods. The results showed that Rice straw extract on seed germination,rice seedling growth differences due to different concentrations of extract, with the increase of extract concentration, the stronger the inhibition, RI value increases. When extract dilution to1:40pm the allelopathy performance role in promoting Similar with the blank test results. Rice straw extract inhibit rice seed germination rate, radicle and plumule length, respectively, lower than that of CK59.5%,58.0%,47.8%.2. Identification of rice straw extract allelochemicalsEthyl acetate as extraction solvent, rice straw Allelochemicals were extracted by ultrasonic and Soxhlet extraction,and then Identified the allelochemicals by GC-MS. By peak area normalization method to determine the relative content of each component.Though Computer retrieval, artificial map resolution, mass spectrometry lobe diagrams and documentation to check peaks,29kinds of chemical composition were identified by these two methods from the rice straw extract, fatty acids and their derivatives as the main category, also contain alcohols, aldehydes, esters, and some hydrocarbons and other organic compounds.GC-MS test showed that the chemical composition:the ethyl acetate extract of the rice straw include caproic acid, benzoic acid, salicylic acid, hexadecane, vanillin, octadecanoic, tetradecanoic acid, vanillic acid,6,10,14-trimethyl-2-15oxazolidinone,4-hydroxy-3,5-dimethyl formaldehyde, are palmitic acid, phthalic isobutyl,17acid, phytol,9-18(carbon) acid,1-15alkyne, linolenic acid methyl ester, stearic acid, cis-11-sixteen carbon aldehyde. Most of the compounds are reported allelochemicals.3. Effect on Microbial fermentation of rice straw in the allelopathicRice straw extract were fermented by EM and Phanerochaete chrysosporium,then Determine the Allelopathy changes of different treatment the extraction. The results showed that rice straw extract can significantly inhibit the germination of rice seeds, radicle, plumule length of rice seedlings seedling height, fresh weight, chlorophyll content. After EM and Phanerochaete chrysosporium fermentation7d,10d extracts and unfermented extract the difference between the very significant level of control consistent with the results. Apparently by EM fungi Phanerochaete chrysosporium fermentation in a relatively short period of time to promote the decomposition of allelochemicals to eliminate rice stubble cytotoxicity, increase soil microbial activity, reduce autotoxicity cropping obstacles.