Water Movement And The Growth Adaptability Of Plant Of Different Layered Soils

In order to search for an optimal soil layer structure for constructing an earth dumping site for the open-pit mine at the Jin-Shaan-Meng bordering region, an experiment on soil water percolation through 4 soil columns different in soil layer structure, was carried out. The four soil columns were homogeneously packed with Sandy Soil, feldspathic sandstone, Loess soil or Red clay, but different in order, that is, Loess Soil-Sandy Soil-Red clay(L-S-R), Loess SoilRed clay-Sandy Soil(L-R-S), Sandy Soil-Loess Soil-feldspathic sandstone(S-L-F), and Loess soil-feldspathic sandstone-Sandy Soil(L-F-S). With the aid of an automatic observation system(AOS) attached to the columns to monitor variation of soil water content with time, and at the same time, change in water level in the markov bottles and wetting front movement was recorded. Based on infiltration rate, cumulative infiltration, wetting front movement and change in profile water content, water percolation through the soil columns different in soil layer structure was characterized. Plant alfalfa On the layered soil column, measure the photosynthetic of alfalfa on the different structure of layered soils, analysis of different structure of layered soil suitability for plant growth. Results show that:(1) Infiltration rate in descending order are Sand, Feldspathic sandstone, Sandy loess and Red clay. Evaporation ratein descending order are Sandy loess, Red clay, Sand and Feldspathic sandstone. Infiltration processes and soil water content under infiltration and evaporation were simulated comparable to measurements. Statistical analysis show that the measured and simulated infiltration rate and moisture profiles of Re is below 11%. R2 is over 0.90. The measured and simulated moisture profiles of evaporative Re is below 6.1%. R2 is over 0.94.(2) Analysis of the infiltration rate, cumulative infiltration, wetting front, profile water content of layered soils infiltration, simultaneously considering climate conditions in JinShaan-Meng adjacent region, then selected the optimal layered soil. S-R-S with poor infiltration ability can not make infiltration rapidly under heavy rain. The wetting front of S-P-S transfers still very fast after reaching the third layer. With a poor water resistance, water leakage to deep soil easily. S-S-R and S-S-P can store large amounts of water in a short time. The third layer of the soil has strong water-blocking effect, especially S-S-R. Statistical analysis show that the measured and simulated infiltration rate and moisture profiles of R2 is between 0.86 to 0.97.The infiltration rate of MEP and SDP is between-0.0004 and-0.0097, 0.025 and 0.039, respectively. The profile water content of MEP and SDP is between-0.0222 and 0.0057, 0.034 and 0.092, respectively. Soil water storage capacity and evaporation performance of layered soils are different. Soil water storage capacity from big to small order is L-R-S,L-S-R,L-F-S,S-LF。evaporation performance From good to bad sort is L-F-S, L-R-S,L-S-R, S-L-F. And the Soil water storage capacity of L-R-S and L-F-S is high, but water is easily loss by evaporation, so the water which can be used by plant is little. The water of L-S-R and S-L-F which can be used by plant is large.(3) At same time, the canopy photosynthetic rate of alfalfa on different layered soil from big to small order are: L-S-R, S-L-F, L-R-S, L-F-S. With group photosynthetic rate evaluation of layered soil suitability for plant growth, according to the appropriate degree of order are: LS-R, S-L-F, L-R-S, L-F-S.