Abstract:

To investigate the effects of applying different livestock manure on the physical properties of sloping cropland soil in the black soil area, chemical fertilizers were used as the control, and three kinds of livestock manure, namely, chicken manure, hog manure and cow manure, were selected for the field experiment. The results showed that the application of livestock manure reduced soil bulk weight, whereas it increased soil aggregates, capillary porosity, soil water content and soil infiltration in cultivated land on black soil slopes, and there were differences among different livestock manures. Compared with the CK (control) group, the chicken manure group had a significant increase in 1-0.5 mm soil aggregate particle size of 82.6% at 30 d and a significant decrease in <0.25 mm soil aggregate particle size of 10.0% at 150 d, whereas the pig manure group had a significant increase in 1-0.5 mm particle size of 49.5% at 90 d. Application of different livestock manures did not significantly affect the geometric mean diameter (GMD) of soil particles, while it significantly affected the mean weight diameter (MWD) and macroaggregate mass fraction (WR > 0.25) of soil particles; WR > 0.25 in the chicken manure group was significantly higher by 10.3% at 150 d compared to the CK group; soil bulk weight decreased by 16.0% and 13.0% at 90 d compared to the CK in the chicken and cow dung groups, respectively; and capillary porosity in the chicken manure group was significantly higher by 50.0% at 60 d compared to the non-capillary porosity which decreased by 38.5%. Chicken manure, hog manure and cow manure significantly increased water content, field holding capacity and saturated water content compared to the CK group; at 90 d, field water holding capacity was significantly increased by 13.7%, 27.7% and 19.1% for hog manure, chicken manure and cattle manure applied compared to CK, respectively; soil water content increased by 9.8%, 21.3%, and 12.1%; soil saturated water content increased by 17.1%, 35.3%, and 26.7%, respectively. Compared with the CK group, the chicken, pig and cow manure groups showed an increase in initial infiltration of 6.2%, 20.5% and 17.9%, in stable infiltration of 1.7%, 23.9% and 4.0%, and in average infiltration of 15.4%, 38.3% and 18.4% at 90 d. The average infiltration of the chicken, pig and cow manure groups was higher than that of the CK group. In addition, correlation analyses showed a negative correlation between soil bulk weight and soil infiltration, soil water content, and soil porosity, and a positive correlation between GMD and MWD, and between soil infiltration and soil water content and soil porosity. In summary, the application of livestock manure can improve the physical properties of soil on black soil slopes cultivated land, and the application of chicken manure is more effective to improve the soil.

Key words: livestock manure, black soil slope cropland, soil physics, soil structure, improved soil