Study On Development Of Functional High-efficiency Biological Rice Seedling Substrate And Its Application Effect

Rice is widely planted in China,but there are many problems in its actual production,such as difficulty in seeding and borrowing soil and serious diseases.Rice sheath blight is one of the three major diseases of rice,and it can be affected from the seedling stage to the panicle stage,resulting in a 50% reduction in rice yield.Therefore,in order to solve problems such as difficulty in taking soil from raising seedlings,serious diseases,etc.combined with the fact that China’s distiller’s grains and other agricultural waste resources are abundant in recent years,the utilization rate is low,and the prevention and treatment of major pathogens have resulted in the development of high-efficiency and biological control functions.The biological rice nursery substrate realizes the resource utilization of agricultural solid waste such as distillers grains and raises the rice seedling raising efficiency.In this study,first the distiller’s grains were mixed with wheat stalks and mushroom slag to ferment and decompose,and three treatments of distiller’s grains,distiller’s grains + stalks,and vinasse + mushroom slag were set up to monitor the change of temperature,nutrient content and other indicators of the compost during the process of maturity,thereby obtaining the decomposed substrate.raw material.After the completion of the decomposing,the rice seedlings of different proportions were made by using vermiculite and perlite as auxiliary materials to carry out the rice breeding test.A total of T1(100% distillers compost),T2(100% straw compost),T3(100% residue compost),T4(40% distillers compost + 20% straw compost + 30% vermiculite + 10% perlite),T5(40% vinasse compost + 20% composted with mushroom residue + 30% vermiculite + 10% perlite),T6(60% composted with(distiller’s grains + straw)+ 30% vermiculite + 10% perlite),T7(distillers’ grains + Mushroom residue)Composting 60% + vermiculite 30% + perlite 10%),T8(commercially available commodity matrix)8 treatments,At the 22 nd day of growth,samples were taken to determine the agronomic traits of the seedlings,the physicochemical properties of the substrate,and other aspects,and the optimum ratio of the rice seedling substrate was explored.Secondly,the strain with antagonistic effect against the rice sheath blight pathogen was isolated from the soil sample by dilute coating method,and the bacterial inhibition rate,fixed nitrogen and phosphorus-solubility of the pathogen against rice sheath blight were quantitatively determined.Then,the above-mentioned growth-promoting strains having antagonistic action against the rice sheath blight pathogenic bacteria were selected and expanded,added to the selected optimum ratio seedling substrate,and rice seedlings were planted,and the following seven treatments were set,A1(The best fit ratio is no bacteria addition to the substrate),A2(optimal ratio matrix + LY5),A3(optimal ratio matrix + LY11),A4(optimal ratio matrix + bacteria X2),A5(optimal Matching matrix + bacteria X3),A6(optimal ratio matrix + bacteria X8),A7(general commodity matrix),A1(optimal ratio base without bacteria),A2(optimal ratio base + bacteria LY5),A3(optimal ratio base + bacteria LY11),A4(optimal ratio base + bacteria X2),A5(The best fit ratios of substrate + bacteria X3),A6(majority ratio matrix + bacteria X8),and A7(ordinary commodity matrix),at the end of 22 days after rice seedlings were raised,the agronomic traits,nutrient content,enzyme activity,etc.of the seedlings were determined.Physical and chemical indicators to explore the growth promoting effect of biological rice nursery substrate;The five strains of antagonistic growth-promoting bacteria selected were combined with the selected optimum ratio rice seedling substrate,and then rice sheath blight pathogens were added to carry out rice seedling raising.The following seven treatments were set,B1(most Adaptation ratio matrix + pathogen),B2(optimal ratio matrix + pathogen + bacteria LY5),B3(optimal ratio matrix + pathogen + bacteria LY11),B4(optimal ratio matrix + pathogen + bacteria X2),The agronomic traits and defense of seedlings were determined at the end of 22 days after the rice was inoculated with B5(optimal ratio matrix + pathogen + bacteria X3),B6(optimal ratio matrix + pathogen + bacteria X8),and B7(common commodity substrate).Sex-related enzyme activity and other physical and chemical indicators to explore the biocontrol effect of the combined bio-nutrient substrate.Combining with research results such as growth promotion and bio-control,we have developed a highly efficient biological rice nursery substrate that has both growth-promoting and bio-control functions.The main results are as follows:1.In compost fermentation stage,the agricultural waste lees as the main raw material,with wheat straw,mushroom residue compost fermentation maturity,at the end of composting,distillers grain,distiller’s grains + straw,vinasse + mushroom residue three treatment temperature above 50 °C The durations were all over 7 days.At the 30-36 d of compost,p H,EC,N,P,K,organic matter,C/N,moisture content,etc.all tended to be stable.Combining compost harmless standards,The compost test proved that the compost maturity had been completed at the end of the 36 th day and could be used for the next experiment.2.Composted compost obtained from compost fermentation stage was used as raw material for different ratios and rice seedlings were raised to select the optimum ratio of rice seedling substrate.The results showed that:(riants + straw)compost 60% + vermiculite 30% + Perlite treatment with 10%(T6)treatment was significantly better than that of commercially available substrates(T8)in the plant height,nitrogen content,phosphorus content,potassium content,and root activity of rice seedlings,which were 13.94% and 12.68% higher than T8 treatments,respectively.,24.62%,5.77%,15.78%,for the optimal treatment,is the ideal rice seedling substrate.3.Based on the determination of the inhibition rate,nitrogen fixation,and phosphate-solubilizing ability,5 dominant strains were screened out to further analyze the colony morphological characteristics,physiological and biochemical characteristics,and the 16 S r DNA conserved sequence identification of the screened strains.The LY5 strain was initially identified as Bacillus subtilis.Bacillus subtilis,LY11 is Bacillus amyloliquefaciens,X2 is Pseudomonas moraviensis,X3 is Bacillus safensis,and X8 is Pseudomonas chlororaphis.4.The selected five antagonistic growth-promoting bacteria were combined with the selected optimum ratio rice seedling substrate to carry out rice seedling raising to explore the promoting effect of the combined biological rice seedling substrate.The results showed that A3(optimal ratio matrix+bacteria LY11)was treated in terms of stem diameter,SPAD value,total dry matter weight of 100 plants,root activity,total root length,total root surface area,average root diameter,and total root volume.For optimal treatment,they were increased by 10.34%,10.05%,3.35%,81.07%,31.30%,35.71%,51.05%,and 51.72%,respectively,compared to A7(Common Commodity Matrix)treatments.5.The selected five strains of antagonistic growth-promoting bacteria are combined with the selected optimum ratio rice seedling substrate,and then rice sheath blight pathogens are added for rice breeding to explore the combined biological rice seedlings.The biocontrol effect of the matrix.The results showed that B3(optimal ratio of substrate + pathogenic bacteria + LY11)treatment significantly increased the number of emergence per plate by 110.5% compared with B1(optimal ratio matrix + pathogenic bacteria),and the incidence was significantly reduced by 89.3%.Reached a significant level;B3 treatment compared to B7(Commercial Commodity Matrix)treatment,although no significant difference in the number of emergence,the incidence rate,but the number of emergence per dish increased by 4.1%,and the incidence rate decreased by 12.5%,indicating B3 treatment The addition of LY11 strain has obvious biocontrol effect on rice sheath blight in actual breeding.The optimum treatments were stem diameter,SPAD value,100 plant dry matter weight,strong seedling index,root activity,total root length,average root diameter,root tip number,etc.,which were 2.26% and 6.01% higher than those of B7 treatment respectively.,4.74%,2.57%,68.03%,15.87%,16.66%,7.83%.In summary,the strain LY11 strain Bacillus amyloliquefaciens selected in this study has both nitrogen and phosphate-solubilizing ability,and has a good antagonistic effect against rice sheath blight pathogens.The most suitable ratio of seedling substrate(60% composted with lees + straw)+ 30% vermiculite + 10% perlite made a highefficiency biological rice nursery substrate,with significant biocontrol effect against rice sheath blight,and can be significant Increasing the seedling raising efficiency of rice lays a theoretical and practical basis for the development of a highly efficient biological rice nursery substrate that has both growth-promoting and biocontrol functions.