Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity s...Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensiometers. The results show that in the profile of whole silty loam soil, the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water; and in the profile with an intercalated bed of clay or with a thick upper layer of clay, the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil. In case of soil water being supplemented by precipitation, the evaporation of groundwater in the soil columns reduced, resulting in a great decline of salt accumulation from soil profile to surface soil. The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer. The direct infiltration depth of precipitation was less than 1 m in general, but water pressure transfer could go up to groundwater surface directly.展开更多
Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in...Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in a plant community dominated by Artemisia ordosica, located on the eastern boundary of Tcngger Desert in the Alxa League, Inner Mongolia, China, were studied to understand whether OM was directly involved in the formation of pedogenic carbonate. The results showed that DHA and CuCO3 positively correlated with OM content, and DHA, OM, and CaCO3 were correlated with each other in their spatial distribution, indicating that abundant OM content contributed to the formation of CaCO3. Therefore, the formation of pedogenic CaCO3 was a biotic process in the plant community dominated by A. ordosica.展开更多
文摘Through a simulation test carried out with soil columns (61.8 cm in diameter), the effect of precipitation on salt-water dynamics in soils was studied by in-situ monitoring of salt-water dynamics using soil salinity sensors and tensiometers. The results show that in the profile of whole silty loam soil, the surface runoff volume due to precipitation and the salt-leaching role of infiltrated precipitation increased with the depth of ground water; and in the profile with an intercalated bed of clay or with a thick upper layer of clay, the amount of surface runoff was greater but the salt-leaching role of precipitation was smaller than those in the profile of whole silty loam soil. In case of soil water being supplemented by precipitation, the evaporation of groundwater in the soil columns reduced, resulting in a great decline of salt accumulation from soil profile to surface soil. The effect of precipitation on the water regime of soil profile was performed via both water infiltration and water pressure transfer. The direct infiltration depth of precipitation was less than 1 m in general, but water pressure transfer could go up to groundwater surface directly.
基金Project supported by the National Basic Research Program (973 Program) of China (No. 2007CB106802)the National Natural Science Foundation of China (No. 30970546)
文摘Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in a plant community dominated by Artemisia ordosica, located on the eastern boundary of Tcngger Desert in the Alxa League, Inner Mongolia, China, were studied to understand whether OM was directly involved in the formation of pedogenic carbonate. The results showed that DHA and CuCO3 positively correlated with OM content, and DHA, OM, and CaCO3 were correlated with each other in their spatial distribution, indicating that abundant OM content contributed to the formation of CaCO3. Therefore, the formation of pedogenic CaCO3 was a biotic process in the plant community dominated by A. ordosica.
