Terraced Land Research Articles

Impact of altitude and slope on soil textural characteristics of terrace lands in Darjeeling under eastern Himalayan region, India

A textural property of soil plays an important role in determining its suitability for crop production. With such hypothesis, the study was undertaken during 2010-2012 in Darjeeling, under eastern Himalayan region. Four sample villages viz ., Sangsay (V 1 ), Dalapchand (V 2 ), Pudung (V 3 ) and Sindebong (V 4 ) located at approximately 5500, 4500, 3500 and 2500 ft. altitudes, respectively were selected for the study. Moreover, soil textural characteristic of terrace lands was greatly varies with altitudes and slope per cent. Results revealed that per cent sand, silt and clay content of surface soil at 0-15cm depth indicates that both bulk densities vary from 1.50-1.75 g/cm ?3 . Particle density on the other hand was found to be relatively higher in V 3 (3.20 g/cm ?3 ) and V 4 (2.98g/cm ?3 ). As a consequence porosity of the soil of these two lower altitude villages were higher and varied from 53.12-44.60 per cent. The clay content, in general, was found to be increasing with the deposition of clay and/or silt at lower altitude through runoff water from the higher altitudes. The higher significant inverse correlation (r = -0.848**) confirms the statement. Only V 4 had the soil clay loam in nature while in all the other villages was of sandy clay.

Impact of long term nutrient management on soil fertility determinants and performance of rice in terraced land

The impact of long term nutrient management practices on soil fertility determinants and performance of upland rice after thirteen years of continuous cultivation on terraced land were studied in a field experiment conducted on the experimental farm of the School of Agricultural Sciences and Rural Development under rainfed conditions. Twelve treatments involving N, P and K (NPK) fertilizers, FYM, poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied for thirteen years and rice crop cultivated continuously. The organic C content, available N, P and K, number of productive tillers, grain and straw yield increased significantly in all the treatments. The highest accumulation of available N, P and K was observed in NPK+ poultry litter, NPK+ FYM and ½N + PK + ½N forest litter treatments, respectively. After thirteen years the rate of build up of available N, P and K in different nutrient management practices ranged from 5.2 to 16.9, 0.33 to 0.80, and 1.96 to 7.03 ha -1 yr -1 , respectively. Addition of FYM and poultry litter with NPK increased 28.7 and 25.9 per cent in grain yield and 50.3 and 49.4 per cent in straw yield, respectively as compared to NPK alone.

The effects of land use and landscape position on labile organic carbon and carbon management index in red soil hilly region, southern China

Labile organic carbon (LOC) and carbon management index (CMI), which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of LOC and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands (pine forest (PF) on slope land, barren hill (BH) on slope land, citrus orchard (CO) on terrace land and Cinnarnornum Camphora (CC) on terrace land) at a sampling depth of 20 cm. Soil nutrients, soil organic carbon (SOC), LOC and CMI were measured. Results showed that the LOC and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC > PF > CO > BH at the upper-slope, while CO > CC > BH > PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order: upper-slope > down-slope > mid-slope. As whole, the mean values of LOC and CMI in different lands followed the order CC > CO > PF > BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a high-quality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.

Investigating extreme flood response to Holocene palaeoclimate in the Chinese monsoonal zone: A palaeoflood case study from the Hanjiang River

Palaeoflood events recorded by slackwater deposits (SWDs) were investigated extensively by sedimentological criteria of palaeohydrology along the upper Hanjiang River valley. Modern flood SWDs were collected for comparison with palaeoflood SWD in the same reaches. Three typical palaeoflood SWDs were observed within Holocene loess-soil blanket on the first river terrace land. The grain size distributions of palaeoflood SWDs are similar to modern flood SWDs, whereas they are different from eolian loess and soil. Palaeoflood SWD lies in three major pedo-stratigraphic boundaries (TS/L0, L0/S0, and S0/Lt) in the Holocene loess-soil profiles. The chronology of three palaeoflood episodes was established by OSL dating and pedo-stratigraphic correlation with the well-dated Holocene loess-soil profiles in the upper Hanjiang River basin. Holocene palaeoflood events were dated to 9500–8500, 3200–2800, and 1800–1700 a B.P., respectively. Palaeoflood discharges were estimated by the palaeoflood model (i.e., slope–area method and step-backwater method). The highest discharges are 51,680–53,950m3s−1 at the 11,500-time scale in the Xunyang reach of the upper Hanjiang River valley. Holocene extraordinary hydroclimatic events in the Hanjiang River often result from abnormal atmospheric circulations from Southwest monsoons in the Chinese monsoonal zone. These results provide a regional expression of extreme flood response to Holocene palaeoclimate to understand the effects of global climatic variations on the river system dynamics.

Impact of Nutrient Management Practices on the Status and Quality of Soil Humus in Newly Developed Terraced Land

An experiment was conducted in the experimental farm at School of Agricultural Sciences and Rural Development, Medziphema, Nagaland to evaluate the impact of different nutrient management practices on content and quality of soil humus in a newly developed terraced land. Twelve treatments involving N, P and K (NPK) fertilizers, farmyard manure (FYM), poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied continuously for two years. On an average, fulvic C, humic C and humin C was 48.1, 21.1 and 30.8% of humus C, respectively. The fulvic C was the largest fraction of humus C in soil followed by humin C and humic C. With the present rate of accumulation of humus C, the soil under different treatments showing build up of humus C would take 3.5 to 66.0 years with an average of 23.2 years to reach its original C content present before terracing. Among the fractions, fulvic N was the largest fraction of humus N in all the treatments followed by humic N or humin N. On an average, fulvic N, humic N and humin N was 58.8, 21.2 and 20.0% of humus N, respectively. After two years, the rate of build up of humus N in various nutrient management practices was 18.3 to 76.4 kg N ha−1 yr−1 with an average of 44.5 kg N ha−1 yr−1. Among the fractions, fulvic P was the largest fraction of the humus P followed by humic P and humin P in all the treatments. On an average, fulvic P, humic P and humin P constituted 65.4, 20.5 and 14.1% of humus P, respectively. The lowest C: N: P ratio of soil humus, fulvic acid and humic acid was in NPK+Poultry litter treatment. The average C: N: P ratios of soil humus, fulvic acid, humic acid and humin was estimated to be 133.1: 10.8: 1, 98.2: 9.8: 1, 138.0: 11.4: 1 and 281.8: 15.0: 1, respectively.

Land forming and tillage effects on soil properties and productivity of rainfed groundnut (Arachis hypogaea L.)–rapeseed (Brassica campestris L.) cropping system in northeastern India

Soil erosion, low phosphorus fertility, and soil moisture stress during winter season are among major limitations to high crop production and sustainable land management in North Eastern Hill (NEH) region of India. Thus, a two years (2009–2011) field study was conducted on a terraced land (980m a.s.l.) to study the impact of land configuration, tillage and residue management on soil properties under rainfed groundnut–rapeseed cropping system. The treatments were: (i) farmers’ practice (FP) (flat bed – residue removal, 3–4 times ploughing); (ii) broad bed and furrow (BBF) with in situ residue incorporation; (iii) BBF with in situ residue+hedge leaves {white hoary pea, Tephrosia candida (Roxb.) DC} incorporation; (iv) BBF with in situ residue+hedge leaves mulching (no-till, NT); (v) raised bed (RB) with in situ residue incorporation; (vi) RB with in situ residue+hedge leaves incorporation; (vii) RB with in situ residue+hedge leaves mulching (NT). Soil profile moisture content was higher under residue retention/incorporation and altered land configuration than that under FP. Water infiltration rate (11.2mm/h) and hydraulic conductivity (6.98mm/h) in soil under RB with residue+hedge leaves mulching (NT) were significantly higher (P=0.05), than that under FP (7.65mm/h and 3.35mm/h) after two cropping cycles. Soil microbial biomass carbon (SMBC) was significantly higher under RB with residue+hedge leaves incorporation (381μg/g soil and 276μg/g soil) than that under FP. Dehydrogenase activity (DHA) was the highest in RB with residue+hedge leaves mulching (NT) (57.8μgTPF/g soil/24h). Soil organic carbon (SOC) and nutrient content improved under residue management. RB with residue+hedge leaves mulching (NT) resulted in the maximum SOC stock, and it was 2.0Mg/ha and 2.7Mg/ha higher than that of the antecedent level and FP, respectively. The average groundnut equivalent yield (GEY) was significantly the highest in RB with residue+hedge leaves incorporation (2815kg/ha) followed by that under RB with residue incorporation (2747kg/ha). Water use efficiency (WUE) of rapeseed was the maximum in RB with residue+hedge leaves incorporation (4.64kg/ha – mm) and the minimum under FP (1.49kg/ha – mm). The BBF and RB land configurations along with residue and hedge leaves mulching under NT improved soil quality and was the most suitable for higher returns of groundnut–rapeseed system under rainfed mid-hills condition.

A new rainwater harvesting and recycling system for transforming sloping land into terraced farmland

Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil erosion. This paper introduces a new system based on rainwater harvesting and recycling technology, which may effectively improve farmland productivity rainwater use efficiency and reduce water and fertilizer inputs. The new system consists of three subsystems: 1) A plough layer with the dual function of crop cultivation and rainwater harvesting; 2) A tank below the plough layer for storing water; 3) An irrigation-drainage subsystem. The plough layer and the storage tank, both treated for reducing seepage, are connected through the irrigation and drainage system. Results showed that, compared with the traditional paddy fields, rice evapotranspiration ( and crop coefficient ) in the test field remained at a similar level, while the irrigation amount was reduced by 44.3% under the condition of basin irrigation, and the drainage amount decreased by 86.6%, and the non-point source pollution was reduced to 67.7%~87.9%, and the rainwater utilization efficiency increased by 30% and reached 95.4%, and crop yield of middle-season rice reached 9,975 kg/hm2, which was only 0.4% lower than that in the traditional paddy field in the terms of dry matter. The new technology sheds light on new possibilities for transformation of hilly sloping land.

Integrated nutrient management on performance of rice in terraced land

Twelve treatments involving N, P and K (NPK) fertilizers, farmyard manure (FYM), poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied continuously for ten years to evaluate the effect of integrated nutrient management practices on performance of upland rice in a terraced land. The plant height, numbers of tillers and productive tillers increased significantly in all the treatments whereas, grain yield increased significantly in all the treatments except ½N+PK and Forest litter burned+½ FYM over control. Among different nutrient management practices, NPK+Poultry litter produced maximum grain and straw yield. The grain yield in NPK+Poultry litter, NPK+FYM+Zn, NPK+FYM and NPK+Forest litter increased significantly (55.9, 45.7, 37.0 and 29.8%, respectively) as compared to addition of NPK alone. Increase in straw yield in different nutrient management practices ranged from 22.0 to 130.0%. The uptake of N, P and K was significantly higher in treatments where NPK was added with FYM and poultry litter. The average contribution towards apparent recovery of N, P and K from FYM was 36.4, 56.2 and 69.2%; from poultry litter 43.5, 27.7 and 85.9%; and from forest litter 80.4, 98.8 and 44.7%, respectively. After a decade of continuous cultivation, NPK+Poultry litter was found to be the best nutrient management practice that can be adopted for cultivation of upland rice on terraced land followed by NPK+FYM+Zn and NPK+FYM.

Analysis of the Summer Season Home Range of Domestic Feral Cats (Felis catus) - Focused on the Surroundings of Rural and Suburban Areas

In order to analyze the home range of feral cats residing in the surroundings of rural and suburban areas, we collected coordination information data from five feral cats. As a result of such research, 100% MCP was defined as minimum 31,500 and maximum 351,900, and 95% KR was defined as minimum 9,400 and maximum 502,800, 75% KR was defined as minimum 3,600 and maximum 126,900, and 50% MCP was defined as minimum 1,800 and maximum 51,700. The home range of feral cats was also analyzed during daytime and nighttime, and all five individuals showed a wider home range during the nighttime than daytime. The analysis of gender shows that the average home range of female feral cats is larger than the average of males. Meanwhile, the results of information data with wide-open areas such as farm land and terrace land on the river showed that the analyzed value was increased generally, and showed variable values depending on the gender and size of each individual feral cat.

Soil quality assessment through a multi-approach analysis in soils of abandoned terraced land in NE Spain

The abandonment of agricultural land in mountainous areas has been an outstanding problem along the last century and has captured the attention of scientists, technicians and administrations, for the dramatic consequences sometimes occurred due to soil instability, steep slopes, rainfall regimes and wildfires. Hidromorfological and pedological alterations causing exceptional floods and accelerated erosion processes has therefore been studied, identifying the cause in the loss of landscape heterogeneity. Through the disappearance of agricultural works and drainage maintenance, slope stability has resulted severely affected. The mechanization of agriculture has caused the displacement of vines, olives and corks trees cultivation in terraced areas along the Mediterranean catchment towards more economically suitable areas. On the one hand, land use and management changes have implicated sociological changes as well, transforming areas inhabited by agricultural communities into deserted areas where the colonization of disorganized spontaneous vegetation has buried a valuable rural patrimony. On the other hand, lacking of planning and management of the abandoned areas has produced badlands and infertile soils due to wildfire and high erosion rates strongly degrading the whole ecosystems. In other cases, after land abandonment a process of soil regeneration has been recorded. Investigations have been conducted in a part of NE Spain where extended areas of terraced soils previously cultivated have been abandoned in the last century. The selected environments were semi-abandoned vineyards, semi-abandoned olive groves, abandoned stands of cork trees, abandoned stands of pine trees, scrubland of Cistaceaea, scrubland of Ericaceaea, and pasture. The research work was focused on the study of most relevant physical, chemical and biological soil properties, as well as runoff and erosion under soils with different plant cover to establish the abandonment effect on soil quality, due to the peculiarity and vulnerability of these soils with a much reduced depth. The period of observation was carried out from autumn 2009 to autumn 2010. The sediment concentration of soil erosion under vines was recorded as 34.52 g/l while under pasture it was 4.66 g/l. In addition, the soil under vines showed the least amount of organic matter, which was 12 times lower than all other soil environments. The carbon dioxide (CO2) and total glomalin (TG) ratio to soil organic carbon (SOC) in this soil was 0.11 and 0.31 respectively. However, the soil under pasture contained a higher amount of organic matter and showed that the CO2 and TG ratio to SOC was 0.02 and 0.11 respectively indicating that the soil under pasture better preserves the soil carbon pool. A similar trend was found in the intermediate soils in the sequence of land use change and abandonment. Soil structural stability increased in the two soil fractions investigated (0.25-2.00 mm, 2.0-5.6 mm) especially in those soils that did not undergo periodical perturbations like wildfires. Soil quality indexes were obtained by using relevant physical and chemical soil parameters. Factor analysis carried out to study the relationship between all soil parameters allowed to related variables and environments and identify those areas that better contribute to soil quality towards others that may need more attention to avoid further degradation processes.

In-situ water conservation in upland paddy field to improve productivity in north-west Himalayan region of India

The hill and mountain agro-ecosystem of NW Himalaya is primarily characterized by limited land under irrigation. Due to farming on terraces, large scale water resource development to store water for supplemental irrigation is not feasible in this region. Construction of trenches may be a good option to hold the runoff and enrich the soil moisture profile. The present study was undertaken to determine the optimal size of the trench through field experimentation, and also to determine the scope of on-farm water management and improvement in soil moisture regime. Four sizes (namely TR1, TR2, TR3 and TR4) of trenches were constructed using 25, 20, 17 and 12 % of the terrace area, respectively. It was observed that all the trenches provided higher average soil moisture and gave 32.9, 50.3 63.6 and 58.4 % higher yield than the control, respectively. However, the yield was statistically at par for TR2, TR3 and TR4. After economical evaluation it is concluded that the trenches may be used as to increase the soil moisture in terraced land, and consequently productivity of upland rice economically, but the area of such trenches must be limited to 12–17 %.

도시 소하천, 대전 탄동천, 수질개선 대안 수립을 위한 QUAL2K 수질모델 구축과 제외지 인공습지공법 적용 효율 평가

The Tandong-cheon stream is a 7.4 km long small urban stream that passes through Daeduk Science Town in Daejeon Korea. Despite the stream has great potential as an educational and recreational site due to its central location in the science town and science museums nearby, environmental aspect especially for water quality has not been evaluated properly. Through field survey, major pollution sources of the stream were identified and effect of water quality improvement alternatives were evaluated using a QUAL2K water quality model for the stream. The study indicated that controlling major pollution sources of the stream alone may not be sufficient for reaching the water quality target. Therefore, additional pollution control methods are necessary. We applied the developed model to evaluate the effects of a constructed wetland on the terrace land, and analyzed whether the water quality target can be met at the outlet of the stream. It is expected that this study would provide a good reference for environmentally sound management of small urban streams in Korea.

Sedimentological study of the stratigraphy at the site of Homo erectus yunxianensis in the upper Hanjiang River valley, China

Geomorphological and sedimentological investigations were carried out in the upper Hanjiang River valley. The sediments in the profile at the site of Homo erectus yunxianensis were sampled systematically. Magnetic susceptibility, loss-on-ignition, particle size distribution and geochemical elements were analyzed in the laboratory. The results show that the medium sand and gravel beds in the lower part of the profile are fluvial deposits of the third terrace land of the Hanjiang River, the upper part is a blanket of aeolian loess and palaeosol deposited from dust storms and dust falls. According to stratigraphical correlation and palaeomagnetic dating, the carbonate nodules encasing the fossils of H. erectus yunxianensis and other mammalian faunas were formed during 800–785 ka. The palaeosol overlying on the fossil layer is defined as the S8 that was developed during the MIS-19, and the aeolian loess below the fossil layer is defined as L9 that was deposited during MIS-20. These loess and palaeosol are similar to those over the Chinese Loess Plateau and correlatable with those in the Luochuan loess profile. They are very different from the fluvial deposits in the Hanjiang River valley. These indicate that H. erectus yunxianensis lived at a climatic transition from glacial to interglacial. These results are very important in understanding the environment of H. erectus yunxianensis in the upper Hanjiang River valley.

Comparative Analysis of Water Reduction Benefits between Terrace and Slope Land in Southern Area of Ningxia: Taking Haoshuichuan Watershed as an Example

Using Haoshuichuan watershed as an example, the infiltration deep of rainfall was analyzed, the comparison analysis of the water reduction between terrace and slope land were worked out through the results of penetration test and soil moisture. The result shows that the ratios of store water in soil to rainfall are 0.81 in terrace and 0.72 in slope land.

Patterns of soil organic carbon, glomalin and structural stability in abandoned Mediterranean terraced lands

Soil carbon (C) storage potential has received considerable attention for its role in climate change mitigation, and much research work has been devoted to studying the effect of land‐use change, including land abandonment, on carbon dynamics. A comparative analysis of soil organic carbon (SOC), easily extractable Bradford‐reactive soil protein (EE‐BRSP) and Bradford‐reactive soil protein (BRSP) was carried out at monthly intervals in a land‐use sequence including cultivated soils, forest soils, shrubs and pasture in northeast Spain. In general, greater seasonal variations of both EE‐BRSP and BRSP were found in soils with less carbon storage capacity. Turnover of glomalin into more stable C forms was associated with a small EE‐BRSP:BRSP ratio in better structured soils and BRSP was related to organic carbon, suggesting positive contributions to both the recalcitrant carbon pool and soil structure. This effect seemed to be more pronounced in August when more BRSP was found, probably because of high temperature and dry soils in which glomalin may react to preserve residual adsorbed water and provide better protection in soil microsites. The role of glomalin was further enhanced by the structural stability of aggregates (WSA) investigated in two aggregate fractions (0.25–2.00 and 2.00–5.60 mm), indicating its beneficial effect in aggregation and carbon storage potential. BRSP, SOC and WSA increased significantly (P < 0.001) along the transect and abandonment sequence; the largest WSA values were generally greater in summer in both aggregate fractions. However, values in cultivated soils were always smaller than in soils under shrubs and pasture. Similarly, soils with a smaller carbon pool had the largest proportion of carbon loss as CO2‐C when land use changes from vines to pasture. The role of aggregates in protecting organic carbon against mineralization was therefore postulated and highlighted the importance of soil monitoring after land abandonment.

Report on the Observation of a Dark morph Tree Sparrow (Passer montanus) in Daejeon Metropolitan City

On March 16th, 2010, at 13:35, a single count of dark morph tree sparrow (Passer montanus) was observed for approximately 15 minutes while it was resting with approximately 30 ordinary tree sparrows at a terrace land on water (east longitude 127°21′31.4”, north latitude 36°18′20.2”) under Gasuwon Bridge (Gasuwongyo) of Gasuwon-dong, Seo-gu in Daejeon Metropolitan City. Dark morph tree sparrow has not been observed in nature for 16 years since its observation in Pyeongtaek-gun of Gyeonggi-do by the Korean Avian Association in 1994.

Influence of land terracing on agricultural and ecological environment in the loess plateau regions of China

The combination of ecological fragility and agricultural activity in the loess hilly–gully regions of western China has received broad environmental concerns. In this region, rainfall and soil moisture can fatally influence crop production under dry land farming. In this study, field experiments were conducted, from March 2001 to September 2005, to demonstrate the variation of soil moisture and fertilizer contents at different depths in slope and terraced lands, and to evaluate the ecological impacts and economic benefits in the terraced land of Loess Plateau. The results of both field test and Grey model (GM) calculation show that the terraced land, as compared to the sloping land, in the agricultural area of the Loess Plateau tends to store and retain much water, promoting more favorable interactions between water and fertilizer. During the months from March to June of the year with less rainfall, the water supply for crop growth is mainly derived from the deep storage of soil moisture accumulated from July to September of the previous year. The field experiments indicate that the crop yield of the 3-year-old terraced lands was 27% higher than that of the sloping lands with slopes greater than 10°, and that the crop yield can increase by 27.07 to 52.78% in the following cultivation years. In particular, potato was found to be more drought-resistant than winter wheat, thus it is more suitable for the arid and semi-arid Loess Plateau regions.

Extraordinary Floods of 4100−4000 a BP recorded at the Late Neolithic Ruins in the Jinghe River Gorges, Middle Reach of the Yellow River, China

Holocene palaeohydrological investigations were carried out in the middle reach of the Jinghe River that drains the central part of the Loess Plateau. A set of palaeoflood slackwater deposits was found interbedded in the Holocene loess-soil sequence within the cliff riverbanks. Both the sedimentary criteria and the analytical results show that this sediment was sourced from a suspended sediment load of floodwater. The major cultural layer of a late Neolithic settlement (4300−4000 a BP) occurring at the same site is blanketed by this flood deposit directly. Slopewash with pottery shards, charcoal and burnt earth occurs in between the palaeoflood slackwater deposit beds. It indicates that each of the slackwater deposit beds has recorded one individual flood event, and that these extraordinary floods occurred when the late Neolithic people occupied the riverbank terrace land. This pre-historical settlement was abandoned after the floods eventually due presumably to repeated inundation by overbank floodwater. The flood events were OSL dated to between 4100 and 4000 a BP and checked by archaeological dating of the anthropogenic remains retrieved from the sequences. Peak discharges of the floods were estimated to between 19,500 and 22,000 m 3 s − 1 , which is several times gauged maximum floods. During the 4200–4000 a BP climatic event, severe droughts were documented in China's monsoonal regions and great floods were known from an ancient legend. This study provides a well-dated sediment record of pre-historical floods which occurred at the transition from the Neolithic to the Bronze Age in the Yellow River basin. It shows that extraordinary floods were part of the abrupt climatic variability during the 4200−4000 a BP climatic event. The highly variable, unstable and catastrophic climate typified by both droughts and floods resulted in settlement abandonment, and possibly the decline of the highly developed late Neolithic civilizations in China's monsoonal regions.

Soil erosion and its basic characteristics at karst rocky-desertified land consolidation area: A case study at Muzhe Village of Xichou County in Southeast Yunnan, China

Xichou County of Wenshan Zhuang and Miao Autonomous Prefecture in southeast Yunnan is one of the karst mountainous areas in southwest China showing typical rock desertification. During this study, we set up three soil erosion contrast test spots at Muzhe Village, Benggu Township, Xichou County, which was the birthplace of the Xichou rock-desertified land consolidation mode. The three spots included the terrace land spot (already consolidated land), sloping land spot (unconsolidated sloping land under rock desertification), and standard runoff spot (bare land spot). In 2007, a whole-year complete observation was conducted during the rainy season and “rainfall-erosion” data were obtained for 32 times. Our analysis showed that during the entire observation period, the number of the rainfalls that led to soil erosion accounted for 34.04% of the number of all rainfalls and the amount of the rainfalls that led to soil erosion accounted for 84.17% of the total amount of all rainfalls. The average erosive rainfall standard in the three test spots was 11.0 mm, slightly higher than the 10 mm standard that has been adopted all over China, but lower than the 12.7 mm standard of the US and the 13.0 mm standard of Japan. According to single-factor analysis, the soil loss in the sloping land spot (L2) and that in the bare land spot (L3) are correlated to certain extent to many other factors, including the single precipitation (P), rainfall intensity during the maximum ten minutes (I10), rainfall intensity during the maximum 20 minutes (I20), rainfall intensity during the maximum 30 minutes (I30), rainfall intensity during the maximum 40 minutes (I40), and rainfall intensity during the maximum 60 minutes (I60). Among these factors, they are of the highest relativity with I60. According to double-factor analysis, both L2 and L3 are of good relativity with P and I60. According to multi-factor analysis, L2 and L3 are also of good relativity with seven rainfall indexes, namely, P, Ia (average rainfall intensity), I10, I20, I30, I40, and I60, with their related coefficient R reaching 0.906 and 0.914, respectively. The annual soil losses in the three test spots are widely different: 1030.70 t/km2·a in the terrace land spot, which indicates a low-level erosion; 12913.22 t/km2·a in the sloping land spot (unconsolidated spot), some 12.5 times than that in the terrace land spot, which indicates an ultra-high-level erosion; and 19511.67 t/km2·a in the bare land spot, some 18.9 times than that in terrace land spot, indicating an acute erosion. These figures fully show that the Xichou rock-desertified land consolidation mode plays a significant role in soil conservation.

Agriculture in Uttarakhand, India—Biodiversity, Nutrition, and Livelihoods

This study investigates food production and agrobiodiversity in the Tarikhet and Ukhimath blocks in Uttarakhand, India, located in the middle ranges of the Himalayas. On the small patches of terraced land available to the average household in these areas, the cultivation of a wide range of traditional and high-yielding varieties of grains, legumes, vegetables, and fruits is a positive feature in terms of sustainability. Some villages also supplement plant-based food production and income by incorporating animal husbandry into the overall agroecosystem. It was found, however, that the output of the average farm provides only about half of the household energy requirements, forcing most families to resort to off-farm activities to support a large proportion of their food and other requirements. There is therefore a need to develop policies that will continue to support the rich agrobiodiversity of these areas, while providing for the nutritional and economic needs of the population.