Influence of Soil Physical Properties on Salt Content in Soil Profile of Farmland in Weibei Region[J]. 2017, 31(4): 198-204.
DOI:
Influence of Soil Physical Properties on Salt Content in Soil Profile of Farmland in Weibei Region[J]. 2017, 31(4): 198-204. DOI: 10.13870/j.cnki.stbcxb.2017.04.032.
Influence of Soil Physical Properties on Salt Content in Soil Profile of Farmland in Weibei Region
Soil salinization is an important type of soil degradation
which seriously restricts the development of agricultural production. Weibei region is the second granary of Shaanxi province. However
due to the higher groundwater level and salinity
the region is suffering from soil salinization
big waterlogging disasters
and high soil compaction for a long time. In order to analyze the influences of soil physical properties
such as water-stable aggregate
soil bulk density and soil texture on salt distribution in soil profile
soil samples were collected from typical farmland in Weibei region through 10 km×10 km mesh point method. The results showed that: (1) soil salinization in Weibei region was not very serious but at a high potential risk. The proportion of mild salinized soil accounted for 45.56%
while the moderate salinized soil only 23.01%. (2) Soil salt content increased with the increasing soil depths in the profile
which indicated that the soil salt would be accumulated to the topsoil with water evaporation in improper managements. Strong negative correlation was observed between water-stable aggregate and soil salt content in the studied profiles. While
the correlation between soil bulk density and salt content varied with the degree of soil salinization. The influence of water-stable aggregate on salt content in topsoil was stronger than that of soil bulk density. However
significant correlation occurred between soil texture and salt content only in 0—20 cm soil layer. (3) The effect of soil physical properties on salt content was not only found in the same soil layers but also in different soil layers. Namely
the ectopic impact was found in the influence of soil physical properties on salt content
and this impact was related to the degree of soil salinization. When salt content was lower than 1 g/kg
a power function relationship was observed between soil bulk density in 40—60 cm layer and salt content in 20—40 cm layer. An increasing function was observed between soil bulk density in 20—40 cm layer and salt content in 0—20 cm layer when salt content ranged from 2 g/kg to 4 g/kg. However
when salt content was higher than 2 g/kg
a decreasing function would be found between soil bulk density in 0—20 cm layer and salt content in 20—40 cm layer. A decreasing function was observed between water-stable aggregate and salt content
especially when salt content was higher than 2 g/kg.