| Magnetization treatment is a new type of water treatment technology,and agricultural research mostly focuses on the effects of magnetized water irrigation on soil physical and chemical properties and crops under normal water condition,but there are relatively few studies on the soil infiltration characteristics of magnetized fertilizer solution and crop effects under stress.According to the development prospect of the integration irrigation of water and fertilizer in China and the development and huge potential of magnetization technology in agriculture,this study carried out the physical and chemical properties,soil infiltration,and greenhouse hydroponic experiments of magnetized fertilizer solution.On the basis of clarifying the changes of the physicochemical properties of the magnetized fertilizer solution,we explored the influences of the magnetized fertilizer solution on soil infiltration characteristics and water and nitrogen transport distribution and clarified the effect of the magnetized fertilizer solution on rape growth and physiological characteristics under water stress,which provides a theoretical basis for the practical application of magnetization technology.The main findings were as follows:（1）Compared with unmagnetized fertilizer solution,the variation trend of physical and chemical properties of magnetized fertilizer concentration showed a certain fluctuation with the increase of magnetic field intensity.Overall,the electrical conductivity of the fertilizer solution decreased and the p H value increased after the magnetization,but the relative changes of the two were small.The dissolved oxygen increased by 5.38%-11.08%,the surface tension coefficient decreased by 0.36%-15.60%under different fertilizer solution concentrations after magnetization and the increase of dissolved oxygen and decrease of surface tension coefficient were positively correlated with the concentration of fertilizer solution.The electrical conductivity,surface tension coefficient,and dissolved oxygen had the largest changes under the condition of 300 m T magnetic field strength.（2）Both the fertilizer solution concentration and magnetization treatment improved soil water infiltration performance.By constructing the functional relationship between the wetting peak migration distance and fertilizer concentration,the wetting peak migration distance of vertical infiltration under different magnetization conditions in a certain fertilizer concentration range can be accurately simulated and calculated.The Philip,one-dimensional algebraic,and Green-Ampt infiltration models could still describe the infiltration process of magnetized fertilizer solution（R2 is above 0.98）.And the soil sorptivity rate“S”,saturated hydraulic conductivity“Ks”,and effective soil water diffusivity“（?）”increased compared with the unmagnetized fertilizer solution.The soil moisture characteristic curve andcomprehensive shape coefficient of the unsaturated hydraulic conductivity“m”and the wet front suction“Sf”at the wetting decreased compared with the unmagnetized fertilizer solution,and the relative variation of the model parameters of the high-concentration magnetized fertilizer solution was larger.There were large errors in the process of parameter extrapolation between the Philip and Green-Ampt infiltration models under the magnetized fertilizer solution condition.（3）The increase of soil water content of magnetized fertilizer solution increased with the increase of fertilizer solution concentration.The one-dimensional algebraic infiltration formula could well describe the distribution of soil water content at the end of soil infiltration of each fertilizer solution concentration under different magnetic field intensities.Both the nitrogen fertilizer solution concentration and magnetization treatment significantly increased soil nitrate nitrogen content at end of the infiltration test,the nitrate nitrogen content of the magnetized high-concentration solution was the highest under their combined effects,which was beneficial to the maintenance of soil inorganic nitrogen.（4）Water stress had a certain inhibitory effect on rape growth,leaf area,aboveground and underground dry and fresh weight,and the inhibitory effect was stronger with the extension of drought stress degree and stress time.Magnetized fertilizer solution significantly improved rape growth and development（P<0.05）,and promoted the change of plant photosynthetic pigment content under different drought stress conditions.Magnetized fertilizer solution treatments improved photosynthesis of rape by decreasing leaf transpiration rate and stomatal conductance and increasing intercellular CO2 concentration.Magnetized fertilizer solution treatments could significantly relieve the effect of water stress on rape growth and physiology. |
