| Loess Plateau is one of the most severe water erosion areas in the world, and rainfall and runoff is the main driving force leading to soil erosion due to spatial and temporal uneven of water and terrain. The water has become the main factor restricting vegetation restoration and ecological environment construction of in the Loess Plateau. The banded hedgerow has been one of the most effective measures for soil and water conservation because of its role in storing energy runoff, regulation and storage water, soil in the Loess Plateau. In this study, Soil moisture dynamic monitoring for 2 consecutive years and soil properties under Caragana korshinskii and Armeniaca sibirica hedgerows were carried out. The analysis of results showed that:(1) There were significant differences about soil bulk density, maximum water holding capacity, non-capillary porosity and total porosity varied significantly among all parts of under Caragana korshinskii hedgerow system(P<0.05). And soil capillary porosity and non-capillary porosity under Armeniaca sibirica hedgerow system and terraces varied significantly(P<0.05). There were differentiations about soil moisture-physical properties among all parts of hedgerow systems due to different types of hedgerows. There were significant differences about the contents of water stable micro- aggregates(<0.25mm) and small aggregates(0.25~2.00mm)(P< 0.05) under two banded hedgerows. Spatial differentiation of water-stable aggregates whose particle size less than 2.00 mm was obviously affected by hedgerows.(2) There were no significant differences about contents of soil sand(0.05~2mm), silt(0.002~0.05mm) and clay(<0.002mm) under two banded hedgerows, while hedgerow can change the relative composition of sand, silt and clay. The content of soil organic matter performed as follow: inner-band(3.57%, grade Ⅱ) > behind band(3.09%, grade Ⅱ) > inter-band(2.72%, grade Ⅲ) > in front of band(2.64%, grade Ⅲ) of Caragana korshinskii hedgerow system, that of Armeniaca sibirica hedgerow system performed as follow: inter-band(1.47%, grade Ⅳ) > inner-band(1.41%, grade Ⅳ). There were differentiations about content of soil organic matter under both hedgerows.(3) The soil water availability of two kinds of ribbon hedgerow inner-band, in front of band, inter-band and after the band are significantly different(P<0.05). Soil water availability of Caragana korshinskii hedgerow increases with increasing distance to vegetation zones, but that of Armeniaca sibirica hedgerows is in contrast. The classification and comparison of soil water availability shows soil moisture of Caragana korshinskii hedgerow inter-band is middle efficiency water, after the band, in front of band, inner-band are difficult efficiency water, but soil moisture of Armeniaca sibirica hedgerows inner-band is easy efficiency water, after the band and inner-band are middle efficiency water.(4) The soil volumetric water content of various parts in Caragana korshinskii hedgerow at 40 cm in the soil except the difference is not significant, but in other soils are significant different(P<0.05). The soil volumetric water content of Caragana korshinskii hedgerow shows as follow: inner-band > after the band > in front of band > inter band and it decreases with soil depth but inner-band is in contrast, The various parts soil volumetric water content of Armeniaca sibirica hedgerows increase and decrease in the same manner, and is not affected by distance to vegetation zones.(5) The sorption capacity and total capacity of reservoir performed that Armeniaca sibirica hedgerow system whose sorption capacity and total capacity was respective 1255.67 t/hm2 and 1358.07 t/hm2 were more than Caragana korshinskii hedgerow system whose sorption capacity and total capacity was 1140.90 t/hm2 and 1253.95 t/hm2, and those of Caragana korshinskii hedgerow system were more than terraces whose sorption capacity and total capacity was 907.20 t/hm2 and 1176.20 t/hm2. The retention capacity of reservoir performed that terraces whose retention capacity was 269.00 t/hm2 was more than Caragana korshinskii hedgerow system whose retention capacity was 113.05 t/hm2, and that of Caragana korshinskii hedgerow system was more than Armeniaca sibirica hedgerow system whose retention capacity was 102.40 t/hm2. Hedgerow can significantly enhance the performance of soil water storage and there were differences between different hedgerow types. The soil actual water storage and the efficiency of reservoir water storage changed with rainfall dynamically, whose trolleying of Caragana korshinskii hedgerow system was least inner-band and maximum inter band, and those of Armeniaca sibirica hedgerow system within all parts are basically the same. Rainfall is the riving factors of soil actual water storage and the efficiency of reservoir water storage, and vegetation type is one of the reasons leading to different trolleying.(6) The total reservoir capacity of reservoir was significantly negatively correlated with soil bulk density(P<0.01) and significantly positively correlated with soil capillary porosity and total porosity, and showed no significant correlations with soil non-capillary porosity, mechanical composition, water stable aggregates and organic matter. Soil structure has effect on soil water storage of reservoir significantly. The regression equation of the efficiency of reservoir water storage and soil factors is Y=29.30-0.44 X3+0.13 X5-1.50 X7+0.30 X8(R2=0.98, P<0.05). The sequence of direct role on the efficiency of reservoir water storage was as follows: Water stable aggregates(X8, 0.84) > clay(X7,-0.67) > non-capillary porosity(X3,-0.40) > sand(X5, 0.22).(7) Soil moisture significantly differed among different parts of hedgerow system and throughout months during the growing season(P<0.05). In inner-band and inter band of Caragana korshinskii hedgerow, the soil drying layer was in the 20-200 cm of soil,while in terraces, the soil drying layer was in the 60-200 cm of soil. The degree of dry layer performances as follow: inner-band of Caragana korshinskii hedgerow system > inter band of Caragana korshinskii hedgerow system > Terraces. The distribution of soil moisture of profile was significantly different. The degree and depth of stable dried layers was significantly exacerbated by hedgerow.(8) There were differences of the degree of soil moisture restoration under hedgerow system during the growing season and in the vertical profile. Compared with terraces, hedgerow can weaken the level of soil moisture restoration, and it was restricted by vegetation, rainfall and soil depth. When vegetation reconstructed, we must consider changes in precipitation, soil properties, vegetation type, and select the appropriate vegetation types and set reasonable planting density in case of the impact of the dried layer of soil. |
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