3. Results
3.1. Effects of
different land use patterns on soil physical and chemical properties
Soil physical properties were significantly affected by land use
patterns (Table 3). Compared with PC, AG and WM significantly reduced
soil BD and increased the contents of WSA (> 0.25 mm). The
WSA contents of AG were mainly concentrated in > 0.5 mm,
accounting for 69.51%, 74.20%, and 73.58% of the total WSA content in
0-20, 20-40, and 40-60 cm soil layers, respectively. The WSA contents of
WM were mainly concentrated in 2-0.25 mm and accounted for 63.68%,
60.88%, and 66.25% of the total WSA content in 0-20, 20-40, and 40-60
cm soil layers, respectively. The WSA contents of PC were concentrated
in > 2 mm and < 0.25 mm.
Soil pH and EC increased with soil depth (Table 4). Compared with PC, AG
and WM increased soil pH in 0-20 cm layer and decreased soil pH in 40-60
cm layer. AG increased EC in 0-20 cm soil layer and decreased EC in
40-60 cm soil layer, while EC in WM was higher than that in other land
use patterns. The contents of SOC,
NH4+-N,
NO3--N, and AP decreased with soil
depth, and these contents of AG and WM were significantly higher than
that of PC. Compared with WM, AG was more helpful to increase the
contents of NH4+-N and
NO3--N in soil.
NH4+-N contents in 20-40 and 40-60 cm
soil layers and NO3--N contents in
0-20 cm soil layer of AG were significantly higher than those of WM and
increased by 9.58%, 13.36%, and 15.06% respectively.