河套灌区农田防护林网内土壤季节性冻融过程及水盐运移

为了解内蒙古河套灌区农田防护林内冻融期土壤水盐状况及运移规律,在2020年10月至2021年4月实测土壤水分、盐分、温度及相关气象数据,并进行相关分析.结果 表明:土体表层温度波动较大,随土层深度加深土体温度变化逐渐平缓.冻结期气温下降速率低于消融期气温回升速率,加之土壤温度变化的滞后性,冻结期比消融期长10天左右.季...

The Seasonal Freezing and Thawing Process of the Soil and the Characteristics of Water and Salt Transport in the Farmland Shelter Forest Net in the Hetao Irrigation District

To understand the status of soil water and salt and its migration laws during the freezing and thawing period in the farmland shelter forest in the Hetao Irrigation District of Inner Mongolia, the soil moisture, salinity, temperature and related meteorological data were measured and analyzed from October 2020 to April 2021. The results showed that the surface soil temperature changed significantly, and leveled off as the increasing soil depths. The rate of temperature decrease during the freezing period was greater than the rate of temperature rise during the thawing period. Considering the hysteresis of soil temperature changes, the freezing period was about 10 days shorter than the thawing period. Seasonal freezing caused the increased water content in the surface soil, and the dereased soil water content in the deep layer. During the thawing period, the soil water content gradually decreased. The surface soil water content in the farmland edges (0.3 H, 4 H) of the forest belts on both sides was smaller than that of farmland (1 H, 2 H, 3 H). The phenomenon of low soil water content in forest belts gradually disappeared with the deepening of soil layers. There was almost no difference in soil water content at different distances from the forest belt in 100 cm soil layer. During the freezing and thawing period, the salt content in soil increased. Soil freezing caused salt to accumulate in various soil layers. During the thawing, soil salt accumulated to the surface layer, and salt reduced in the deep soil. The degree of soil salt accumulation in farmland near forest belt was stronger than that in far forest belt. The transports of water and salt in soil basically showed a significant correlations, and the variability of salt was greater than that of water, indicating that the process of salt transport was more complicated. The results of this study revealed the law of soil water and salt movement in the farmland within the protection forest during the freezing and thawing period, and could provide a basic theoretical basis for agriculture in the irrigation area.