Effect Of Soil Compounding On Photosynthetic Physiology And Yield Of Alfalfa

In this paper,for the problem of soil quality deterioration in a large area of sandy land formed by the exploitation of aeolian sand,which leads to the difficulty of vegetation restoration,this paper tries to use the sandy sandy soil of mu us sandy land with its loamy soil and soft sandstone,(HT type compound soil),soft sandstone and sandy soil mixed soil(PT type compound soil),and combined with alfalfa planting experiment to analyze the mechanism of alfalfa for the recovery of sandy land restoration and reconstruction and ecological environment,so as to provide a scientific basis.The main conclusions are as follows:(1)With the increase of proportion of loessial soil and sandstone,the sand content and soil bulk density decreased,the content of clay and silt particles increased,two type soils all showed a change of sand-loam-silt loam soil.the variation ratio of PT type soil is more obvious than HT type soil.(2)With the proportion of loess soil and soft rock in the complex soil,Pn,Gs,Ci,WUE,qP,ETR,?DPS?,Fv/Fm,Chla,Chlb and Chlt of alfalfa showed the phenomena that increased first and then decreased,Tr increased with the increase of the ratio and qN decreased first and then rose gradually.(3)Both types of compound soils were most favorable for alfalfa photoreaction at 25%ratio,and the effect of the same type of HT type compound soil was better than that of PT type compound soil.The three most favorable treatments for alfalfa growth were HT25>PT25>HT50.The yield of HT25,PT25 and HT50 alfalfa increased by 427.55%,302.77%and 291.30%compared with the CK,respectively.It is suggested that the mix ratio of 25%is good for crop growth when the sub-parent material was mainly yellow soil/sandstone;when the two sub-parent material had same or similar available conditions,HT25 type is more favorable than PT25 for plant growth.