The Characters of Dry Soil Layer on the Loess Plateau in China and Their Influencing Factors

PLoS One. 2015 Aug 4;10(8):e0134902. doi: 10.1371/journal.pone.0134902. eCollection 2015.

Abstract

A dry soil layer (DSL) is a common soil desiccation phenomenon that generally forms at a particular depth in the soil profile because of climatic factors and poor land management, and this phenomenon can influence the water cycle and has been observed on the Loess Plateau of China and other similar regions around the world. Therefore, an investigation of the DSL formation depth (DSLFD), thickness (DSLT) and mean water content (MWDSL) on the Loess Plateau can provide valuable information. This paper synthesized 69 recent publications (1,149 observations of DSLs from 73 sites) that focused on DSLs in this region, and the results indicated that DSLs are significantly affected by climatic and vegetation factors. The mean annual precipitation had a significant positive relationship with DSLFD (p = 0.0003) and MWDSL (p<0.0001) and a negative relationship with DSLT (p = 0.0071). Crops had the lowest DSLT and highest MWDSL values compared with other vegetation types. A significant correlation was observed between the occurrence of DSLs and the years since planting for grasses, shrubs, trees and orchards, and the severity of DSLs increased with increasing planting years and wheat yield. Our results suggest that optimizing land-use management can mitigate DSL formation and development on the Loess Plateau. Understanding the dominant factors affecting DSLs will provide information for use in guidelines for the sustainable development of economies and restoration of natural environments experiencing water deficiencies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture / methods
  • China
  • Climate
  • Conservation of Natural Resources
  • Crops, Agricultural / growth & development
  • Desiccation
  • Ecosystem
  • Global Warming
  • Meteorological Concepts
  • Plant Dispersal
  • Poaceae / growth & development
  • Seasons
  • Soil*
  • Triticum / growth & development
  • Water Cycle

Substances

  • Soil

Grants and funding

The study was financially supported by the National Natural Science Foundation of China (41390463) and the National Key Technology R&D Program (2015BAC01B03). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.