Study On The Impact Of Slag On The Nutrient Dynamics Of Water-soil-plant System

In the paper, the impact of application of slag on the dynamic water-soil-plant nutrient system was studied. When the lag was applied, the temporal and spatial variation of PO43-, NH4+-N, SO42-, DOC in water and available phosphorus, available nitrogen, MBC, DOC in soil, and the effect on the nitrogen and phosphorus accumulation in rice plants were analyzed. The adsorption and analytical effect of slag on N, P was illustrated. The conclusions can be got as follows:(1) The application of slag reduced the phosphate and ammonia content in the surface water. In the whole rice growth period, the size relation between the phosphate content in the surface water of four samples was the control plot>2Mg hm-2>4Mg hm-2>8Mg hm-2, and the size relation between the ammonia content in the surface water of four samples was the control plot>2Mg hm-2>4Mg hm-2>8Mg hm-2. Although the application of slag reduced the phosphate and ammonia content in the surface water, it could increase the content of phosphate and ammonia in deep soil water. The average phosphate content in the0-30cm soil layer water of8Mg hm-2plot was35.4%higher than that of the control plot. The average ammonia content in the0-30cm soil layer water of sample plot with4Mg hm-2was41.1%higher than that of the control plot. The application of slag reduced the sulfate content in the surface water and the deep soil water.(2) A comparative analysis of available nitrogen, available phosphorus and MBC, DOC and content in four different treatment plots was developed. The results showed that the size relation of the soil available N, the available P content was8Mg hm-2>4Mg hm-2>2Mg hm-2> control plot. The size relation between the MBC was:2Mg hm-2>4Mg hm-2>8Mg hm-2> control plot. The differences among the four plots were not significant. The relationship between the soil DOC content was4Mg hm-2>2Mg hm-2>8Mg hm-2> control plot. The difference of DOC content between the control plot and the sample plot imposed by4Mg hm-2was significant.(3) The adsorption of slag and soil on phosphate was in line with the Langmuir isotherm model. The adsorption isotherm of slag and soil on ammonia equaled to the Freundlich isotherm equation. Both of the correlation coefficients were above0.97. (4) The size relation between accumulation phosphorus in the stems and leaves parte in four sample plot was8Mg hm-2>4Mg hm-2>2Mg hm-2>control plot, and the size relation between the rice P accumulation was also8Mg hm"2>4Mg hm"2>2Mg hm-2>control plot. The size relation between N accumulation in the stems and leaves was8Mg hm-2>4Mg hm-2>2Mg hm-2>control plot, and the size relation between the rice N accumulation was8Mg hm-2>2Mg hm-2>4Mg hm-2>control plot. The variance analysis showed that the difference between the control plot and the8Mg hm-2plot was significantly. The application of slag not only increased the nitrogen content in the root and stem, but also increased the nitrogen content in rice.