Soil water condition of terraced orchard in loess hilly and gully region

Soil water is an important factor for affecting plant growth and development in the arid and semiarid areas. In order to study interannual dynamics and the compensation characteristics of soil water deficit of terraced orchards, the present study investigated the soil water contents of slope croplands, terraced croplands and terraced orchards in later April and in later October from 2003 to 2010 in the loess hilly and gully regions. The results show that the terraced croplands can significantly decrease the interannual variation of soil water storages in the 0-300 cm soil layer, improve the soil water content, and decrease the water storage deficit. The soil water storages in the 0-300 cm soil layer of the terraced orchards are significantly fluctuated interannually, the soil water contents are decreased remarkably below 200 cm and the water deficit is raised, and the compensation of the water deficit is dropped from 20% to -10%. In conclusion, the water storage in the terraces can not offer enough water to balance the water consumption of plants for evaporation, and the terraced orchards can result in a reduction of soil water and finally lead to a soil dry layer.