Abstract:
Returning organic materials to farmland can improve soil physical properties. For the low-yield albic soil with barrier albic layer, few studies were conducted on the effects of different organic materials on soil physical properties and crop yield in different soil layers. In this study, the typical albic soil in the management area of 852 farm, Shuangyashan City, Heilongjiang Province was taken as the research object. Through the experiment of returning different organic materials to the field for two consecutive years, the effects of no organic materials returning to the field (CK), straw returning to the field (S), organic fertilizer returning to the field (M), straw and organic fertilizer returning to the field (SM) on the physical characteristics of the whole plough layer (0 - 35 cm) of albic soil and corn yield under deep plowing conditions were explored. The results showed that compared with CK, S, M and SM treatments significantly reduce the soil bulk density and the deviation value of soil three phase ratio in the 0 - 15 cm and 15 - 35 cm soil layers, respectively, while increase the generalized soil structure index; the soil bulk density of SM treatment in 0 - 15 cm and 15 - 35 cm soil layers is significantly lower than that of CK by 4.71% and 6.10%, respectively (
P < 0.05). The maize yield of SM treatment is significantly higher than that of other treatments, with an average annual increase of
2 935 kg·hm
−2 compared with CK. Correlation analysis showed that 15 - 35 cm soil porosity, soil bulk density and 0 - 15 cm soil bulk density exhibit the most significant effects on maize yield, and their contribution to maize yield is 7.32%, 7.31% and 6.98%, respectively. In summary, deep tillage combined with straw and organic fertilizer returning can improve the physical characteristics of the 0 - 35 cm soil layer of albic soil, promote the distribution of soil three-phase structure to an ideal state, and increase maize yield. This research provides theoretical basis and technical reference for the construction of suitable tillage layer for crop growth in the albic soil region of Northeast China.