Fig 1.
(Yaoshi Town, Shangluo City, Shaanxi Province, China).
Fig 2.
The distribution map for the division of the test area.
Table 1.
Root characteristics of different types of herbaceous plants.
Fig 3.
Scan of Lolium perenne(a), Cynodon dactylon(b) and Medicago(c).
Table 2.
Distribution of root length at different diameter classes for three herbaceous.
Table 3.
The number of root tips, root forks and root crosses of different plants.
Fig 4.
Soil moisture characteristics curve under different plant treatments.
(a is for Medicago; b is for Cynodon dactylon; c is for Lolium perenne; d is for Control treatment).
Fig 5.
Axial line shrinkage of soil under different plant treatments.
Fig 6.
Transient swelling rate of soil under different plant treatments.
Fig 7.
Correlation analysis between root diameter class and soil linear shrinkage and swelling rates under Lolium perenne treatment.
P: swelling rate of soil; X1, X2, X3: the line shrinkage of the minimum, maximum and inflection points of suction; H1, H2, H3, H4, H5, H6: respectively denote the root lengths of 0<L< = 0.5mm, 0.5<L< = 1.0mm, 1.0<L< = 1.5mm, 1.5<L< = 2.0mm, 2.0<.L.< = 2.5mm, 2.5<.L.< = 3.0mm; Z:and total root systems; * p < 0.05 and ** p < 0.01.
Fig 8.
Correlation analysis between root diameter class and soil lead rate and swelling rate under Medicago treatment.
P: swelling rate of soil; X1, X2, X3: the line shrinkage of the minimum, maximum and inflection points of suction; M1, M2, M3, M4, M5,M6: respectively denote the root lengths of 0<L< = 0.5mm, 0.5<L< = 1.0mm, 1.0<L< = 1.5mm, 1.5<L< = 2.0mm, 2.0<.L.< = 2.5mm, 2.5<.L.< = 3.0mm; Z:and total root systems; * p < 0.05 and ** p < 0.01.
Fig 9.
Correlation analysis between root diameter class and soil linear shrinkage and swelling rate under Cynodon dactylon treatment.
P: swelling rate of soil; X1, X2, X3: the line shrinkage of the minimum, maximum and inflection points of suction; G1, G2, G3, G4, G5, G6: respectively denote the root lengths of 0<L< = 0.5mm, 0.5<L< = 1.0mm, 1.0<L< = 1.5mm, 1.5<L< = 2.0mm, 2.0<.L.< = 2.5mm, 2.5<.L.< = 3.0mm; Z:and total root systems; * p < 0.05 and ** p < 0.01.
Fig 10.
Content of clay, silt and sand particles in the soil under different treatments.
Fig 11.
Pore volume in soil under different treatments.
Fig 12.
Content of organic matter in soil under different treatments.
Fig 13.
Microscopic morphology of soil under different treatments at 500 μm scale.
(a is for Control treatment; b is for Cynodon dactylon; c is for Medicago; d is for Lolium perenne).
Fig 14.
Microscopic morphology of soil under different treatments at 200 μm scale.
(a is for Control treatment; b is for Cynodon dactylon; c is for Medicago; d is for Lolium perenne).