Application Research Of Sediment In Shifosi Reservoir In Rice Planting

The sediment is an important part of the water environment and is mainly composed of minerals,organic matter,nutrients,active microorganisms,heavy metals and other substances.If the dredged sediment is arbitrarily stacked and landfilled,it will not only occupy land resources,but also cause secondary pollution due to rain erosion,and waste nutrients contained in the sediment.Therefore,the use of sediment resources is a crucial issue.Through the existing research,the comprehensive utilization methods of various sediments have been comprehensively compared,and it is found that the utilization of sediments is the most economically feasible disposal method.The problem of sedimentation at the bottom of Shifosi Reservoir is becoming more and more serious.It is necessary to carry out sediment dredging.How to properly handle the disposal of sediment and rational use of sediment is the key content of this study.Based on the analysis of the physicochemical properties of the reservoir sediment,the rice pot experiment was carried out by mixing the sediment with the soil of the tillage layer in different proportions.The effect of the sediment on the growth of rice was studied and revealed.The evaluation and analysis of the changes of soil nutrients and heavy metals provide a more valuable way for the comprehensive utilization of sediments in Shifosi Reservoir and achieve the maximum resource utilization efficiency of sediments.The main conclusions are as follows:(1)The physical and chemical analysis of the bottom mud of Shifosi Reservoir shows that the nature of the sediment is weak and alkaline;the nutrient content is rich,which is better than the soil properties of the cultivated field near Shifosi Reservoir;the heavy metal content meets the national standards and can be used for agricultural integration.use.Therefore,the experimental scheme was determined to mix the sediment and the tillage soil in different proportions to analyze the effects on rice growth and development.(2)The effects of fertilization and unfertilized treatment on rice growth and yield under different sediment application rates were studied by experiments on the rice mixed with soil and soil.The results showed that the bottom mud can increase soil nutrient content and increase soil fertility.When the sediment is applied more,the rice yield is higher,especially when the sediment and fertilizer are combined,the rice yield increases obviously,indicating that the sediment is applied to the soil.Crop growth has a promoting effect and can be used for agriculture.(3)The application of sediments promoted the absorption of nitrogen and phosphorus in rice.With the increase of sediment application rate,the absorption of nitrogen and phosphorus increased gradually.The absorption of phosphorus was mainly reflected in the regreening stage and the tillering stage.It is not obvious;the absorption of nitrogen increases with the increase of the amount of sediment application,which indicates that the increase of nitrogen in sediment application is more obvious than that of phosphorus.The content of heavy metal elements in the soil changed after the application of sediment,but within the range of soil quality standards specified by the state,the order of change of heavy metal elements in soil was:Zn>Cu>Cr>Pb>Cd.