In order to explore the response of irrigated silt soil to different tillage methods and different biochar additions,the nutrient content and enzyme activity were measured,in order to provide a scientific basis for selecting suitable tillage methods and fertilization systems in the Hexi Corridor region.An 8-year field experiment was conducted with four tillage methods(N:no-tillage,M:less-tillage,F:autumn ploughing,S:subsoiling)and three biochar application rates(B1:2.5 t/hm2,B2:5.0 t/hm2,B3:7.5 t/hm2)in maize field,and without tillage and no application of biochar was the control(CK).The results showed that:(1)In the 0-20 cm soil layer,compared with CK,different treatments significantly increased soil organic carbon,available nutrients and enzyme activity(P<0.05).Soil organic carbon,available nutrients and soil enzyme activity increased with the increase of biochar application rate under different tillage methods.(2)In 20-40 cm soil layer,compared with CK,different treatments increased soil organic carbon,available nutrients and enzyme activity,but there was no significant difference among treatments(P>0.05).(3)Different treatments could increase maize yield,but there was no significant difference among treatments(P>0.05).Compared with CK treatment,the yield-increasing effect of each biochar treatment was between 0.07%and 21.30%,and the yield of FB3 treatment was the highest,which was significantly higher than that of other treatments(P<0.05).(4)Correlation analysis showed that there was a significant positive correlation between soil nutrients and soil enzyme activities(P<0.05).Subsoiling tillage combined with biochar addition could effectively improve soil nutrients and enzyme activity,which was conducive to crop growth,and it was a more suitable tillage method in this area.Biochar above 7.5 t/hm2 could be applied as an important additive for the improvement of irrigated silt soil.