Study On Water Dynamic Among Belt Of Stands On Forestland And Water Resource Moderately Used In The Northwest Plateau Of Hebei Province

Aimed at "returned farmland to forest and grassland" in Bashang of Hebei province, allowance is at term, ecologic and economic problems were faced by government and peasants. This experiment was conducted in Zhangbei experiment station of Agricultural University of Hebei in Zhangjiakou in 2005. As for young and 43 years old forestland, intercropping with soybean, alfalfa, and cushaw as treatments, soil water dynamic of space among forest belt were studied. Water leakage of naked-oats and cushaw was also studied. The main results are as follows:1 The water leakage of naked-oats and cushaw were separately 1.0mm, 2.3mm. Plastic-film mulching made the soil water content of cushaw field 30.5mm more than naked-oats, and increase 1.3mm water leakage. There were better ecological benefit to plant cushaw. Cushaw biomass was 3 416.7kg/hm~2, was 39.5 %of naked-oats. The economic production was 11 605.8yuan/hm~2, was 2.10 times of naked-oats. The WUE of cushaw reached to 52.3 yuan/hm~2.mm, was 2.41 times of naked-oats. Based on the barren land of bashang, high water leakage, high economic production and low biomass, made cushaw to be the best crop to produce both ecologic and economic benefit in bashang.2 As for 4years old elm forestland, soil water dynamic of space among forest belt were studied. In the 4 intercropping systems, the accretion of ground-diameter and plant height of intercropping treatments were higher than CK. But there were not significant difference.In each intercropping system, water consumption of forest belt was about 224 mm. Far away the forest belt, that is, weed land and crop land, water consumption of weed land was 225.6mm, had no difference with forest belt. Water consumption of soybean, soybean alfalfa and cushaw were separately 230.8mm, 237.2mm and 245.6mm, there were significant difference with weed land.The economic production of cushaw was the highest, was 4 446.7 yuan/hm2, 1.85 times of naked-oats. The economic production of soybean and alfalfa were separately 1 193.1 yuan/hm~2 and 880.0 yuan/hm~2, 49.7 % and 36.7 % of naked-oats.3 As for 43 years old poplar forestland, soil water dynamic of space among forest belt were studied. Water consumption of each observation site in the distance which supply water to forest belt was about 220mm, was close to the weed land. The water consumption distance of CK, laomandmai and alfalfa were separately 6m, 8m and 10m. All in the 1 times of plant height of forest belt. The water consumption distance and chest-diameter was positive.4 The water consumption of each plant in growing period of 2005 was about 225 mm,water consumption of one crop were different in different years because of different precipitation, and water consumption of different crops were had no difference in one year with the same precipitation. The decreased soil water content was about 0-20 mm.5 In the system of intercropping with cushaw, near the forest belt, the soil water content was higher for the shade of cushaw leaves, it was good for the growth of forest, especially in the drought years. Far away the forest belt, cushaw can grow well and produce high production because of the use of mulch film. So forest belt intercropping with cushaw was a good example of gaining both ecological and economic benefit.