Abstract:A two-year field experiment was conducted to evaluate the effect of applying mushroom residues on soil properties, wheat root growth and yield in the region of the ancient Yellow River. 7 treatments were designed, i.e., no mushroom residue (CK), straw-based mushroom residue at the rates of 6, 12, and 18 t/hm2 (S1, S2, and S3 respectively), xylary mushroom residue at the rates of 6, 12, and 18 t/hm2 (B1, B2, and B3 respectively). The results showed that compared with CK, applying mushroom residues increased wheat yield by 32.4%-51.8% and 38.8% -101.2% in the 1st and 2nd year, respectively (P<0.05), and stepwise regression showed that applying 1 t/hm2mushroom residues improved crop yield by 0.21 t/hm2(P<0.01). Applying straw-based mushroom residues of 18 t/hm2 achieved the optimal agronomic and economic incomes, however, no significant differences in wheat yield and economic income were found between straw-based and xylary mushroom residues (P >0.05). After the two-year application of mushroom residues, soil organic matter content increased by 24.7%-57.7% (P<0.05), bulk density and compactness significantly decreased by 11.6%-18.2% and 20.8%-35.7%,respectively (P<0.05; B1 excepted). Root traits showed positive correlation with wheat yield. Applying mushroom residues significantly increased the total root length, surface area, total volume, and folks (P<0.05). Wheat yield had positive correlation with soil organic matter content but significant negative correlation with 0-10 cm soil bulk density and compactness, which indicate that increasing soil organic matter and improving soil physical properties by applying mushroom residues are essential mechanisms for wheat yield enhancement. Our study indicates that for farmlands with low soil organic matter and less favorable physical structures in the low-yield cropland of ancient Yellow River area, applying mushroom residue is effective to improve soil physical properties and fertility, promote wheat root growth, increase wheat yield and economic income.