| Soil degradation caused by erosion and loss of vegetation is the principal problem to sustainable ecology in the xerothermic regions. Revegetation is considered as the essential process of soil restoration. The results of a trial on xerothermic soil rehabilitation in Yuanmou xerothermic regions by restoring native Heteropogon contortus community indicated:1. Soil physical properties in the 0~40cm profile were effectively improved in the plot after 12 years restoration compared with the open grazing plot (control). Significant differences (n=3,p<0.05) between two plots were recorded in soil bulk density in the 0~20cm profile, and, in total porosity, capillary porosity, saturated water content and capillary water content in the top 0~10cm Extreme differences (n=3,p<0.01) were found in both two water holding capacity indices in the 0~10cm profile.2. Thirteen months soil water data from the 10~th year restoration in the 0~180m profile showed that soil water content and storage capacity increased compared to the control. Firstly, the rainfall infiltration was 60cm deeper. Moreover, soil volumetric water was 0.00 %~45.15% higher in the rain season (from May to Oct.) while 2.91%~21.76% higher in the dry season (from Nov. to Apr.). Finally, the average soil water storage capacity in 0~ 180cm profile presented an increment of 50.02mm than the control (424.57mm). However, soil moisture in both plots within 0~40cm profile showed a similar seasonality dynamic to the natural precipitation.3. Soil fertility was notably improved along with the restoring in the first 10 years, but positive changes were found mainly in the top 0 ~20cm profile. Extremely significant (n=3, p<0.01) differences in soil organic matter were found between two plots. SOM in the top soil 0~10cm of restoring fields increased 63.32% and 49.80% in the 7th and the 10~th year, respectively, compare with the grazing fields while in the 10~20cm layer increased 94.98% and 77.29%. Concurrently, total nitrogen, available nitrogen and available potassium notably increase and all showed the significant or extreme significant differences from the grazing plot. Whereas, soil pH declined slightly along with the restoring, and, available phosphor could not be detected in both sites. The increase of total amount of soil microbes (bacteria, fungi and actinomyce) were recorded in the top 0-10cm in the restoring field. In both sites, the amount in 0~40cm layer varies along with the alteration of seasons by a trend of mid-rain-season> the end of rain season> the end of dry season> mid-dry-season. The change of the amount of bacteria, fungi and actinomyce respectively showed accordance with their individual behaviors in both sites. Although above changes occurred during the restoration the low fertility level implied the long run process of soil restoration.4. The increase rate of canopy coverage, aboveground biomass(dried) of Heteropogon contortus community in 6~12 on-farm restoring fields hit 285.35%~691.89% (n=3,p<0.01) and 1400%— 3743.92%(n=3,p<0.01) respectively; species number were also built up.these results presenting positive effects of revegetaion. The nutrient values of the principal species in Heteropogon contortus community were assessed at the end of research as the middle glass and palatable to cattle, buffalo, goats anddonkey.A conclusion produced by this research is that self-restoring of Heteropogon contortus community can benefit not only to the soil water and fertility improvement but also contribute to revegetation in degraded xerothermic soils; the restored community provides good prospects in live stocking industry by adequately grazing and the possibility to achieve the harmony of regional ecology with economy.
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