Effects of different tillage practices of soil biopores and nonbiopores structures in sugarcane field soils of Guangxi

【Objective】 To investigate the effects of traditional rotary plowing and Fenlong tillage on the biopores and non-biopores structures of sugarcane field soils in Guangxi，which could provide theoretical basis for the rational selection of tillage practices in sugarcane production in this region. 【Method】 Using the soil in sugarcane field as object，soil samples were collected during the elongation period of sugarcane using 2 treatments，namely，20 cm Fenlong tillage （F₂0）and 20 cm traditional rotary tillage（X20），to determine the distribution of soil particles，bulk density and organic matter content of the soil layer from 0 to 40 cm depth. The two-dimensional and three-dimensional feature parameters of soil biopores and non-biopores space were obtained by using X-ray CT scanning technology combined with ImageJ 1.53c and MATLAB 2019a，and the pore structure was visualized by three-dimensional reconstruction under the 2 treatments. 【Result】 Compared with X20 treatment，the average clay content of 0-40 cm soil layer in F₂0 treatment was significantly reduced by 32.16%（P<0.05，the same below）. In comparison，the average silt content was significantly increased by 12.82%. The biopores two-dimensional number with 0-10 mm pore diameter of F₂0 treatment was higher than that of X20 treatment，and the difference of the non-biopores two-dimensional pore number between the two was not obvious；the biopores roundness in F₂0 treatment was significantly increased by 10.58% compared with X20 treatment. Among the threedimensional pore parameters，the connectivity of biopores in F₂0 treatment was significantly increased by 67.55% compared with X20 treatment，and the rest of the parameters were smaller than X20 treatment；the porosity，tortuosity，connectivity，and specific surface area of non-biopores in F₂0 treatment were lower than those in X20 treatment，but the differences were not significant（P>0.05）. In the three-dimensional reconstruction maps，the biopores of the X20 treatment were only mostly distributed in the 0-10 cm soil surface area，while the biopores of the F₂0 treatment formed more downward-extending continuous tubular structures in the 10-30 cm soil layer；the distribution of the non-biopores in the X20 treatment was more sparse；and more non-biopores existed around the main growing area of the crop root system in the F₂0 treatment. 【Conclusion】 The biopores structure formed by Fenlong tillage is superior to that of traditional rotary plowing，especially in the formation of upper and lower connected biopores and denser distribution of non-biopores， which can better promote the formation of water and fertilizer transport channels. In the process of sugarcane cultivation in Guangxi，Fenlong tillage can be used to effectively improve the soil pore structure.