Study On The Regulation Mechanism Of Silicon Fertilizer On Rice Under Salt Stress

Rice is one of the main food crops in China.The use of brackish water irrigation can solve the problems of agricultural water demand and freshwater resource shortage to a certain extent,but the salt stress will affect and restrict the growth and development of rice,and silicon can alleviate the salt stress to a certain extent.Therefore,the experiment took rice as the research object,cultivar"Jinyuan 89"was selected,four levels of salt content of irrigation water were set for W0,W1,W2 and W3(salinity:0,3,4 and 5g/L),and three different foliar application rates of silicon fertilizer were set for F0,F1 and F2(silicon application rate:0,6kg/hm~2,12kg/hm~2),SPSS 26.0 and Excel were used for statistical analysis to study the effects of silicon fertilizer on the growth traits and yield of rice during the whole growth period under brackish water irrigation.Applying silicon fertilizer under brackish water irrigation mode can alleviate salt stress to a certain extent,promote the absorption of root nutrients and the growth and development of rice,so as to improve rice yield,and save fresh water resources.Based on the environmental conditions of rice growth period,the Aqua Crop crop growth model was used to simulate the growth and development of rice,and the simulation verification was carried out based on the data of this experiment,so as to provide reference for the formulation of water,fertilizer and salt regulation plan.The main conclusions are as follows:(1)Under brackish water irrigation with different salinity,increasing the amount of silicon fertilizer can effectively promote the growth of plant height and leaf area,photosynthesis and nutrient absorption of rice,and increase rice yield.Rice plant height under 3g/L irrigation increased by 2.12%-47.85%compared with that without silicon fertilizer during the whole growth period.Under 4g/L irrigation,the effect of silicon fertilizer on rice leaf area index was significant,which increased by 17.47%at most.(2)Application of silicon fertilizer can promote the growth and development of rice roots and increase the absorption of nutrients.Under 12kg/hm~2 silicon fertilizer,the growth of total root length,total surface area and total volume of rice roots increased by 22.81%,58.10%and 40.85%,respectively,compared with that without silicon fertilizer.(3)Under salt stress treatment during the whole growth period,rice yield and its related components decreased with the increase of salt stress,but applying silicon fertilizer can alleviate salt stress and promote rice growth and development to a certain extent.The dry matter weight of the overground part and root system was significantly reduced by applying silicon fertilizer under the treatment of 3g/L irrigation water,which could increase the dry matter weight by 11.62%and 26.85%,and increase the yield by17.00%.(4)Aqua Crop crop growth model was used to simulate the growth of rice,and combined with the analysis results of crop growth traits and yield,the simulation results of rice biomass and yield were consistent with the measured results,which could be used as a simulation study for the optimization of silicon fertilizer and brackish water irrigation system in the future.