Study on Soil Physical Properties of Terraced Slope Farmland in Black Soil Region of Northeast China.

To explore the soil water holding capacity and soil structure on sloping farmland with terrace measures in Black Soil Region of Northeast China. The construction of terraces slope farmland in different soil types (Black soil, Dark brown soil and Brown soil) is taken as the research object, the slope farmland (non- terraced slopes) was used as a blank control (CK). In the study, the spatial uniform distribution method was used to quantify the soil water holding capacity, soil structure characteristics and spatial distribution characteristics of construction of terraced slope farmland. The results showed that (i) the physical properties of soil after terrace construction in Black Soil Region were better than that of CK, and the improvement degree was Brown soil > Black soil > Dark brown soil. (ii) Compared with the CK, the soil physical properties of Brown soil in terrace slope farmland were improved obviously. The soil saturated water holding capacity of terrace slope farmland increased by 10.24 %. Besides, the soil capillary water holding capacity of terrace slope farmland increased by 16.77 %, and the soil field water holding capacity of terrace slope farmland increased by 16.10 %. Compared with the CK, the soil structure characteristics of Brown soil in terrace slope farmland were also more stable, and he total soil porosity and capillary porosity of terraced slope farmland increased by 9.14 % and 15.56 %. (iii) Terraced slope farmland of Brown soil mainly affect soil moisture characteristics and soil porpsity, in which soil capillary water holding capacity with 12.11 % of contribution rate, and the contribution of terraces to total soil porosity was 11.21 %. The main influencing factors of terraces in Dark brown soil were soil structure characteristics, in which the contribution of soil total porosity was 13.84 %, and the contribution of water-stable aggregate content was 13.31 %, which were greater than that of CK ; The contribution rate of each index of terrace of Black soil is relatively uniform, at 10.24 % -12.5 %. In summary, the terraces of Brown soil affect the characteristics of soil moisture and soil structure. The terraces of Dark brown soil mainly affects the characteristics of soil structure. Terraces of Black soil mainly affect soil moisture characteristics.

Keywords : black soil region; terraces; soil water holding capacity ; characteristics of soil structure ;