内蒙古平原灌区土壤固碳与养分吸附特征及秸秆还田调控OA北大核心CSTPCD

In order to provide theoretical basis for straw fertilizing high-yield field and improving saline-alkali field in the process of continuous high yield and stable yield of spring corn in Inner Mongolia plain irrigation area.This study set up a positioning test of corn straw returning to the field for 1 to 4 years(HT1-HT4),taking the straw not returning to the field as the control(CK).Soil organic carbon content,total nitrogen content,available nitrogen content,available phosphorus content,cation exchange capacity,pH value and acid-base buffer curve were measured before spring sowing and during harvest.The results showed that,the relative change rates of soil organic carbon content,total nitrogen content,available nitrogen content,available phosphorus content and cation exchange capacity were 1.34％-3.62％,0.20％-1.51％,-0.11％-0.78％,0.89％-6.36％and 0.09％-0.41％during harvest period of HT1-HT4 compared with that before spring sowing.The relative change rates of soil organic carbon content,total nitrogen content,available nitrogen content,available phosphorus content and cation exchange capacity were 1.57％,-0.02％,-0.45％,-0.15％and-0.05％in CK harvest period compared with that before spring sowing.Soil pH value of HT2,HT3 and HT4 was significantly lower than that of CK.The buffer capacity of soil to alkali was HT4＞HT3＞HT2＞HT1＞CK.In summary,with the increase of straw returning years,soil carbon sequestration capacity,fertilizer retention capacity and buffering performance in-crease,and the ability to effectively resist drastic changes in soil pH value caused by fertilizer application and other factors was enhanced,soil quality was significantly improved by straw returning to field for fertilizer cultivation and soil improvement measures.