Study On The Soil And Water Conservation Via Hedgerow In The Slope Farmlands In Southern Hilly Region Of China

In order to screen out hedgerow species and planting patterns, which are suitable for the control of soil erosion in the slope farmland of southern hilly region of China,we chose two different hedgerows (Ophiopogonis and Hemerocallis),and we chose six kinds of hedgerow treatments (Hemerocallis planted in single rows, Hemerocallis planted in double rows, Hemerocallis+Ophiopogonis, Ophiopogonis planted in single rows, Ophiopogonis planted in double rows, bare slop)of soil as the research object, the runoff plot were investigation aids. The impacts of plant and planting pattern on the soil nutrient conservation against the soil erosion and the impacts of physicochemical properties on Soil and Water Conservation in the slope farmland were studied and analyzed under suitable laboratory conditions.1.The research results show that the soil total nitrogen content under Ophiopogonis planted in double rows was higher than other hedgerow treatments.When Ophiopogonis were planted in single and double rows, the soil available nitrogen contents were higher than other treatments. Hemerocallis treatments suffered low available nitrogen contents. In terms of soil conservation, the hedgerow treatments reduced soil sediment loss remarkably. Under the high rainfall density, the Ophiopogonis treatments outperformed the Hemerocallis treatments, the double row treatments worked better than the single row treatments, regarding the soil conservation. Overall, the double-row Ophiopogonis treatment worked the best in reducing the soil sediment loss.2. The results showed that the soil bulk density had significant negative correlation with total porosity, aggregates content and clay content in different treatment, soil bulk density had significant positive correlation with sand content in different treatment.Soil organic matter content had significant positive correlation with total nitrogen content and available nitrogen content in different treatment.Runoff had significant negative correlation with soil organic matter content and total nitrogen content.Quantity of sediment had significant positive correlation with soil bulk density and sand content quantity of sediment had significant negative correlation with total porosity, the>0.25mm water stable aggregates content and clay content.Using principal component analysis on Soil anti-erodibility in different treatment, we have obtained four best indicators for soil anti-erodibility:sand content, soil bulk density, total porosity and clay content. Soil physical properties are the main factors affecting the soil anti-erodibility. The order of comprehensive principal component of anti-erodibility from big to small in different treatment is:Ophiopogonis planted in double rows, Ophiopogonis planted in single rows,Hemerocallis+Ophiopogonis, Hemerocallis planted in double rows,Hemerocallis planted in single rows and bare slop.3. Soil moisture of different treatment exhibited moderate spatial variation. The comparison of different treatment of soil moisture content in the same slope section Hemerocallis planted in double rows of uphill> Hemerocallis planted in single rows of uphill>bare slopes of uphill; Hemerocallis planted in double rows of midslope> Hemerocallis planted in single rows of midslope>bare slopes of midslope;Hemerocallis planted in double rows of downhill>Hemerocallis planted in single rows of downhill>bare slopes of downhill. The same treatment of soil moisture content in different slope section:uphill<midslope<downhill.4. Soil moisture content has a relationship with the monthly rainfall.When the monthly rainfall was large and the soil moisture is also a corresponding relatively large.Different treatments of soil water content were significantly different.bare slop,Hemerocallis planted in single rows and Hemerocallis planted in double rows were significant difference in soil moisture.Hemerocallis planted in single rows and Hemerocallis planted in double rows were not significant in soil moisture.the soil moisture of the bare slopes is less than hedgerow treatments when just after rainfall.The bare slope soil moisture Dissipated fast than the hedgerow treatments.