A Study of Soil Nutrients in the Terrace Field Changed from Mountain Slope in Three Gorges Reservoir Region

In order to accurately grasp the soil fertility in Three Gorges Reservoir Region after changing mountain slope into terrace field,we take Wushan County for example,and use the spatio-temporal substitution method to analyze the soil nutrient status and trend about the terrace field changed from mountain slope under different length of implementation.The results show that the soil fertility is generally low in the study area,and according to the soil nutrient grading standards in the second national land survey,the average content of total nitrogen,available potassium,organic matter and available phosphorus reaches Standard III,Standard III,Standard IV and Standard V,respectively,and the spatial heterogeneity of soil nutrients is small.Compared to the sloping land,the terrace field changed from mountain slope has increasing soil nutrients on the whole with the length of farming.The mean of various indicators about soil nutrients in the terrace field changed from mountain slope for 2 years is lower than in the sloping land,and there is the biggest difference in soil fertility,while the mean of various indicators about soil nutrients in the terrace field changed from mountain slope for 14 years shows a linear upward trend,and the difference in soil fertility decreases.

Elevation and Land Use Types Have Significant Impacts on Spatial Variability of Soil Organic Matter Content in Hani Terraced Field of Yuanyang County,China

Soil organic matter （SOM） content is one of the most important indicators of the sustainability of soil. To maintain sustainable soil utilization and management in fragile Hani terraced field, it is meaningful to investigate the effects of topography and land use type on SOM content. Descriptive statistics and geostatistics were used to analyze the data and the kriging method was applied to map the spatial patterns of SOM content. The results showed that the mean SOM content was 32.76 g/kg, with a variation coefficient of 40%. The SOM content was affected by elevation and land use type. As the increase of elevation, the SOM content in Hani terraced field also increased obviously. The SOM content in tea garden, which is almost at high elevation, was the highest in all six land use types, and the SOM content decreased in a following sequence： tea garden 〉 paddy field 〉 corn field 〉 banana garden 〉 cassava field 〉 sugarcane field. In addition, at the same elevation, the paddy field had the highest SOM content compared with other land use types. All these results demonstrate that paddy field is the most efficient and suitable land use type for SOM conservation at high, middle or low elevations in the fragile Hani terraced field. In order to protect soil quality and maintain the sustainable agricultural development, it is necessary to maintain or even to enlarge the area of paddy field in Yuanyang county, Yunnan Province, China.

Initiation and Kinematic Process of Debris Flow with the Existence of Terraced Fields at the Sources

A debris flow,with terraced fields as the source area,broke out on June 25th,2018 in the Xiaotuga area of Yunnan Province,China,and this kind of debris flow is rarely recorded.Two purposes in this study:(1)the influence of flow drag force on slope stability;(2)back-analyze the movement process of debris flow.First,the geological background and movement of this debris flow were described based on a field investigation.Then,drag force,calculated by the laminar flow theory,is added to the slope stability calculation model,which elaborates the initiation process of this disaster.Moreover,dynamic simulation software(DAN3D)was used to simulate the kinematic process of the debris flow with a variety of combination models.The study shows that the terrace area can quickly produce surface runoff and create a drag force under rainfall conditions,which is the essential reason for the initiation of debris flow.In addition,the use of the FVV(Frictional-Voellmy-Voellmy)model is found to provide the best performance in simulating this type of debris flow,which reveals that it lasts approximately 200 s and that the maximum velocity is 12 m/s.

Factors Influencing Indigenous Rice Protection in the Yuanyang Terraced Rice Fields of China

Indigenous rice has maintained the survival of local people for more than a thousand years in the Yuanyang terraced rice fields of southern Yunnan, China. It is the foundation for long-term stable development of local agriculture and food security and its unique and irreplaceable characteristics give the terraces value. The status of indigenous rice resources is threatened by serious loss, so a better understanding of rice diversity and the factors that influence rice variety protection is conducive to policy. Here, we investigate the planting and conservation situation of indigenous rice, analyze factors impacting the protection and loss of traditional rice varieties, and construct an indigenous rice protection influence index system. Controllable factors which have special meaning to the maintenance and management of local rice are identified and corresponding strategies for the protection and maintenance of indigenous rice are discussed.

Analysis on the long term discharge of a catchment

In this study, the characteristics of the long term discharge of a Terraced Paddy Field Catchment are studied. 2 Kind of Tank Models are proposed and used to simulate the discharge of the catchment. The characteristics of the model simulations of the discharge of the catchment are analyzed and compared with those of a forest catchment.

"A Fortified Mountain Village" "Terraced Fields"

These two paintings depict the living environment of Hani and Yi ethnic nationalities which inhabit the Ailao Mountains in Southwest China. The paintings, while realistic, display some slightly decorative techniques. The communities live harmoniously, building terraced fields and

Agro-pedological Assessment of the Traditional Yuanyang Rice Terraces of Yunnan Province, China

As a contribution to a long-term evaluation of the sustainability of agro-ecosystems in the Yuanyang rice terraces, this paper reviews the bio-physical environment of the terraced landscape in a small catchment around Qingkou village and assesses soil fertility in the village crop growing area. A soil- landscape organization pattern was developed using a geomorphopedological approach. Anthropogenic, climatic and topographic factors were identified as the main soil forming factors. Soil capability and associated edaphic constraints were assessed and the main soil types were identified and classified using FAO protocols. Spatial patterns of soil fertility appear quite homogeneous. Soils are acid and cation exchange capacity and nutrient reserves are generally low. The agro-ecosystem has largely been developed by the Hani population. This agro-ecosystem has succeeded in maintaining a relatively dynamic nutrient circulation system. Current research is focusing on： （i） the evaluation of the representativeness of the studied area compared to the whole terraced system in the Yuanyang terraced landscape; （ii） measurements of nutrients flows at the field scale; （iii） the effects of soil properties on crop yields; and （iv） up-scaling field levels results to larger spatial units.

湘闽赣山区劳动力转移差异对梯田荒决策和规模的影响

In recent years,the phenomenon of abandonment of cultivated land in mountainous areas has occurred frequently,and the problem of abandonment has become a focus of attention of government agricultural departments and academic circles.However,few studies have paid attention to the impact of differences in labor transfer on the abandonment behavior of farmers’terraced fields.Based on this,this paper takes the terraced fields of Hunan,Fujian and Jiangxi provinces as the research area,combined with data from 1438 farmer households,and uses the Probit and Tobit models to analyzed the impact of the difference in the quantity,distance and quality of labor off-farm transfer on the decision-making and scale of terraced field abandonment of farmer households.The results show that:(1)The greater the quantity of labor transfer,the farther the transfer distance and the higher the quality of non-agricultural employment,can promote the decision of farmers to abandon terraced fields;(2)With the deepening of the degree of non-agricultural transfer,the scale of abandoned terraced fields by farmers in hilly and mountainous areas will also expand;(3)The distance and quality of labor transfer can strengthen the impact of labor transfer quantity on farmers’decision to abandon land.To alleviate the phenomenon of abandoned terraced fields,the government should pay attention to the labor substitution role of agricultural service outsourcing and mechanization in mountainous areas.The government should actively promote the transformation of terraced fields into mechanized farming,improve the cultivated land transfer market,and encourage farmers to transfer terraced fields.

The Effect of the Irrigated Gudeuljang Paddy System on Biodiversity on Cheongsan-do(“island”)

This study has been conducted to identify the characteristics of the biodiversity promoted and maintained by gudeuljang paddy field.For this purpose,a literature review was used to identify the distribution of gudeuljang paddy field on Cheongsan-do.Based on the results of the review,a target area was selected to conduct an investigation of the flora of the vascular plants and a phytosociological examination,which included general farmlands and neighboring areas,was made for comparison.As a result of the study,we were able to identify the differences between the type of gudeuljang paddy field that uses continuous irrigation and other types of land use.We found that the unique physical structure for water passage found in gudeuljang paddy fields with continuous irrigation is more effective in promoting biodiversity than the other types of land use in this area.In conclusion,the presence of gudeuljang paddy fields on Cheongsan-do contributes more to the creation of an appropriate biohabitat than it detracts from such a creation.Also,the presence of gudeuljang paddy fields is significant in that it exercises positive influence on the promotion of biodiversity,such as propagation of species,and the connection of habitats in adjacent forest,village,and farm lands.Our result shows that the maintenance and preservation of gudeuljang paddy fields on Cheongsan-do plays a crucial part in the preservation and maintenance of the biodiversity for vegetation that grows among rocks and in adjacent forest areas.