Abstract:

In order to improve the efficiency of water resources in arid areas, make sure the area of poplar artificial mill reasonable water supply, and realize the goal of poplar plantation scientific control, based on 4-year term located experiment of supplying different annual water supply capacity (1500 m3/hm2, 3000 m3/hm2, 4500 m3/hm2, 6000 m3/hm2 and 7500 m3/hm2), it was investigated on effects of soil moisture and temperature for forest land of Populus popular’s in the Ulanbuh sandy area. The results showed that: soil humidifying effects of poplar forest land differed significantly among 5 treatments of different annual water supplied. Soil water content of every soil layer and every month increased with the increase of annual water supply. The peak value of soil water content for the maximum annual water supply happened in July and the others happened in June. Fast-growing poplar’s annual water supply threshold was the 7500 m3/hm2, this annual water supply could make recharge layer of soil water maintain above 70 cm depth, and could make soil water content of recharge layer and high temperature period (6-9 months) remained above 20%. Increasing water supply, the decreasing amplitude of soil water content would be enlarged along with the increase of stand age. Each additional water volume of 1500 m3/hm2 could raise 4.69%-7.43% of water storage content and 1.42%-15.5% of effective soil water content. The effect of water supply on field water capacity was unremarkable. With the increase of water supply, the value of soil water deficit mitigated significantly, and soil temperature reduced 1.66-3.26℃ within the same soil layer and reduced 8.64-9.66℃ down along soil profile. Water supply of minimum and maximum should be carried out in April (low-temperature period) and in July (high-temperature period) to meet the needs of water and temperature for stands growth.