Prevention Of Soil Loss Research Articles

The Spatial and Temporal Dynamics of Soil Conservation and Its Influencing Factors in the Ten Tributaries of the Upper Yellow River, China

Soil erosion is a global environmental problem, and soil conservation is the prevention of soil loss from erosion. The Ten Kongduis (kongdui is the translation of “short-term flood gullies” in Mongolian) are ten tributaries in the upper Inner Mongolia section of the Yellow River Basin. The study of the spatial and temporal variability in soil conservation in the Ten Kongduis is of extraordinary scientific significance both in terms of the discipline and for the ecological and environmental management of the region. With the InVEST model, the characteristics of the spatial and temporal variations in soil conservation service in the Ten Kongduis since 2000 and how rainfall and land use have influenced soil conservation were analyzed. The results show that both avoided erosion and avoided export varied considerably between years. The minimum values of avoided erosion and avoided export were both in 2015, with values of 17.59 × 106 t and 0.92 × 106 t, respectively. The maximum value of avoided erosion was 57.03 × 106 t in 2020 and that of avoided export was 4.08 × 106 t in 2000. Spatially, avoided export was primarily found in the upper reaches of the east–central portion of the study area, and avoided erosion, with values of >40 t·(ha·yr)−1, was in the upper east–central portion of the study area, followed by the upper west–central portion. The difference between upstream and downstream was larger in the western part of the study area. The effect of rainfall was dominant and positive in both avoided erosion and avoided export. The relationships between the rain erosivity factor and the values of avoided erosion and avoided export were significantly positive. Where more erosion occurs, more erosion is retained. Soil that has been eroded away from slopes under vegetation or other water conservation measures may not necessarily be transported to the stream channel in the current year. These conclusions will help us to have a clearer understanding of where sediments are generated and transported and provide a scientific basis for soil and water conservation and ecosystem safety management of watersheds.

137Cs-based analysis of soil redistribution in the Integrated Watershed Management intervention area in northern Ethiopia

Spatial patterns of trace isotope cesium-137 (137Cs) can be strongly correlated with soil movement in a landscape, thereby allowing assessments of soil erosion and deposition processes, based on these patterns. Our study assessed how soil organic carbon (SOC) stocks were related to the redistribution of 137Cs in prevalent forest and agricultural land-use systems in a north Ethiopian watershed undergoing land rehabilitation. Composite soil samples were collected from 0 to 5, 5–10, 10–20, and 20–30 cm layers of exclosures, croplands, rangelands, and bare lands at different slope positions. Reference samples were collected from a vegetated hilltop with no anthropogenic soil disturbance history. The use of 137Cs analysis was not effective in revealing SOC dynamics in croplands, which was probably a result of soil tillage and generally low SOC contents. Otherwise, 137Cs tracing was a suitable method for the soil redistribution assessment in the tropical environment, owing to sufficient amount of the isotope detected following the original fallout. Comparisons of 137Cs contents between the reference and sampling sites revealed a gap in 137Cs inventories in 87% of all locations, thereby indicating severe erosion, especially on the backslopes. Some of the examined samples, mostly from rangelands and exclosures, exhibited 137Cs activities that were higher than the reference, signifying these sites as depositional areas for soil material eroded elsewhere. Soil movements indicated by 137Cs profiles, were particularly substantial in rangelands, where 137Cs stock varied significantly according to the slope positions and soil depths. Notably, significant correlations between SOC stocks and 137Cs levels in exclosures suggested that both the prevention of soil loss and the capture of soil eroded from degraded sites fortified SOC accumulation. This suggests that not only the increase in vegetation cover but also the soil deposition was an attribute of the land rehabilitation process.

Vegetation Drastically Reduces Wind Erosion: An Implementation of the RWEQ in the Mongolian Gobi Steppe

Soil loss prevention is an important ecosystem service for protecting human and environmental health. Using spatiotemporal climate and environmental data of the Eastern Gobi Steppe, a region missing from previous studies of Mongolian wind-based soil erosion, we implemented the Revised Wind Erosion Equation (RWEQ) model to estimate soil loss. A replicable pipeline was developed to perform these computations, and made available openly. Soil loss was estimated on a monthly basis to analyze seasonal variations. The results show that the annual total soil loss was 61 × 1010 kg over an area of 69.3 × 103 km2, which is about 90 tonnes per hectare. Increasing fractional vegetation coverage to a uniform 50% coverage (doubling current vegetation coverage in every 1 km2) could reduce soil loss by 60%, highlighting the importance of protecting and increasing vegetation coverage in ecosystem service preservation.

SOIL EROSION CALCULATION USING AERIAL IMAGES BASED DTM IN A CROSS BORDER VINERY REGION

Abstract. This paper shows the effect of different terrain models extracted out of nadir and oblique aerial surveyed data and the processing to DTM with respect to soil erosion risk evaluation. A cross border area between Germany and France, close to the city of Wissembourg, was affected by soil-erosion several times in the past. Vineyards aligned with the slope improve the risk for soil erosion. Applying the Universal Soil Loss Equation (USLE) in GIS-environment highlights areas of higher or lower risk in order to assist in strategies for a better the soil loss prevention. The lack of sufficient soil data limits the spatial resolution of the study and details given are mainly provided through the very dense terrain model. Nevertheless, terrain is one of the major factors defined in the slope angle and slope length.

Effects of tillage-induced soil surface roughness on the generation of surface–subsurface flow and soil loss in the red soil sloping farmland of southern China

The role of tillage-induced soil surface roughness (SSR) in altering surface–subsurface flow and soil loss needs to be investigated in the red soil region of southern China. In this study, two different roughness conditions (smooth surface and rough surface), produced by plowing with and without flattening, were employed to assess the effects of surface roughness on rainfall redistribution, surface and subsurface flow generation, and soil loss. In-situ rainfall simulations with three different rainfall intensities (30, 60, and 90 mm h−1) during 180 min of rainfall were tested for a steep farmland sloped at 15°. The results showed that the rough surface had a higher capability for improving subsurface flow, whereby 34% of the rainfall changed into surface flow, and 24% changed into subsurface flow; whereas the proportions of surface and subsurface flow on the smooth surface were 40% and 16%, respectively. The rough surface exhibited a faster initial generation of surface flow and subsurface flow, and the progress of erosion from sheet erosion to rill erosion was more rapid than on the smooth surface, leading to a higher sediment yield from the rough surface under stronger rainfall events. However, the rough surface demonstrated enhanced infiltration behavior and prevention of soil loss under low-intensity rainfall events. The difference in soil crusts on smooth and rough surfaces was the dominant factor affecting surface–subsurface flow generation and soil loss from the red soil sloping farmland. The roughness decreased on the rough surface and increased on the smooth surface during rainfall events. The interactions between surface and subsurface flow should be considered to evaluate soil loss; hence, this research provides a comprehensive understanding of the impact of tillage activities on soil erosion.

Changes in soil functionality eight years after fire and post-fire hillslope stabilisation in Mediterranean forest ecosystems

Contour-felled log debris (CFD) and log erosion barriers (LEB) are two restoration practices used worldwide on hillslopes to avoid soil erosion after wildfires. Although significant work has evaluated the effectiveness of these practices on soil loss prevention, their effects on soil properties have been little researched to date. Here, the effects of CFD and LEB treatments on several physico-chemical and biological soil properties were investigated across four post-fire zones in Mediterranean forest (Sierra de Los Donceles, Spain). Results suggest that post-fire management similarly altered the recovery of microbiological soil properties and soil functionality for both CFD and LEB treatments. Post-fire management enhanced soil organic matter (SOM) and basal respiration, while suppressing soil microbial activities. SOM enhancement at our plots may have been associated with suppressed soil microbial decomposition activity due to post-fire increases in electrical conductivity. Plots with post-fire management recovered microbiological soil properties better than unmanaged burn plots, but not to the same level as nearby unburned plots. LEB and CFD may not only be effective in retaining sediments, but also in improving post-fire microbiological soil properties in comparison to unmanaged plots. However, after eight years of post-fire management, soil microbiological soil properties did not completely recover compared to unburnt areas. That is, fire may shift the development trajectory of microbiological soil properties so that they may no longer be able to return to the same unburnt conditions. Post-fire restoration plans should consider the use of LEB and CFD when aiming to aid soil-related ecosystem recovery processes after wildfires.

Ways to reduce the risk of loss of soil diversity

The article is devoted to the problem of reducing the risk of loss of soil diversity in the Russian Federation. The methods of quantitative assessment of the degree of soil degradation are considered. The discussion points of compiling the Red Book of Soil and its difference from the Red Book of plants and animals are analyzed. The main way to preserve the diversity of natural soils is to ensure the representativeness of the system of specially protected natural areas (PA). The representation of soil diversity in the modern network of PA in Russia is estimated (about 56 %). Prevention of soil loss is presented in the form of a triad: a quantitative assessment of the degree of soil degradation, the introduction of endangered natural soils in the Red Books (lists) and the development of proposals for the organization of new PA with the inclusion of “Red Book” soils. Topical issues are the problems of preserving soil diversity in significantly anthropogenically altered regions, as well as determining the minimum area of a protected site that is necessary and sufficient to preserve virgin soil as a specific taxonomic unit.

Effect of moss crusts on mitigation of post-fire soil erosion

Mosses and wildfires are ubiquitous occurrences. Their correlation has been assessed in few studies. Mosses have been pointed as pioneer species in post-fire environments. However, reasons for moss crusting in post-wildfire soils and their ecosystem role in preventing soil erosion have not been quantitatively assessed. Moss crusts have quickly developed after a wildfire in a hillslope of eucalypt plantations, in central Portugal. This study had as the overarching aim comparing post-fire soil erosion and runoff between different moss cover percentages, combined with other protective cover elements throughout the first year after fire. Overland flow, sediment and organic matter losses were examined at micro-plots presenting different moss cover percentages, both between plots (11–46% in average) and across time (0–75%). While development of moss cover tended to increase the runoff response, a moss cover above 67% significantly reduced sediment and organic matter losses by 65% (0.40 Mg ha−1) and 34% (0.15 Mg ha−1) respectively, especially during the rainiest season. Given that mosses are very fast soil colonizers after wildfires, these results provide clues for considering moss crusts in post-fire management and demonstrate their importance in ecosystem restoration, including prevention of soil loss.

Rill erosion processes on a steep colluvial deposit slope under heavy rainfall in flume experiments with artificial rain

Understanding rill erosion processes is important in the prediction of soil erosion and the prevention of soil loss. However, limited information is available concerning the impacts of rainfall on rill erosion on steep slopes. Colluvial deposits with steep slopes make up the packed material underlying the collapsing walls in benggang, which collapse due to hydraulic pressure and gravity. They contain loose materials and large amounts of coarse particles. The objectives of this study were to investigate the impacts of rainfall intensity and slope gradient on the rill erosion process, rill development and rill flow dynamic mechanisms on the steep slopes of colluvial deposits. The colluvial soils were subjected to simulated rainfall in a 5-m2 (5-m by 1-m) flume at heavy rainfall intensities (100, 120, and 140 mm h−1) and on five steep slopes (20, 25, 30, 35, and 40°). Rill erosion contributed significantly to colluvial slope erosion; on average, rills accounted for 61% of the soil loss, and the effects of slope gradient were greater than those of the rainfall intensity. After rill development, rill density, rill length, width, and depth all significantly increased. Correspondingly, the soil loss rate sharply raised and irregularly fluctuated. Moreover, the collapse of rill heads or sidewalls tended to increase the relative contribution to rill erosion and rill development. The rill flow was characterized by transitional and subcritical flow regimes. The rill flow velocity was the most sensitive hydraulic parameter, and the unit stream power provided the optimal hydrodynamic parameter to characterize the dynamic mechanisms of rill erosion on colluvial deposits. The collapse of rill heads or sidewalls could result in negative values for critical shear stress, critical stream power, and critical unit stream power of rill erosion, which were −19 Pa, −5.3 N m−1 s−1, and −0.09 m s−1, respectively. These results provide a better understanding of the mechanism of rill erosion on steep slopes.

Effect of National-Scale Afforestation on Forest Water Supply and Soil Loss in South Korea, 1971–2010

Afforestation of forests in South Korea may provide an example of the benefit of afforestation on precipitation storage and erosion control. In this study, we presented the effects of afforestation on water supply and soil loss prevention. A spatio-temporal simulation of forest water yield and soil loss was performed from 1971–2010 using InVEST water yield and SWAT models. A forest stock change map was produced by combining land cover data and National Forest Inventory data. The forest water yield increased about twice with changes in forest stock and climate from 1971–2010 and showed a spatially homogeneous water supply capacity. In the same period, the soil loss decreased more than three times, and the volatility of soil loss, in the 2010s, was smaller than before. The analysis of the change in forest stock without considering climate change showed an increase of 43% in forest water yield and a decrease of 87% in soil loss. An increase in precipitation increased the water yield, but also increased the soil loss volume. A change in forest stock led to positive changes in both. This study presents functional positive effects of the afforestation program in South Korea that can be useful in various afforestation programs in other countries.

The Effect of Soil Textures on the Flowering characteristics and Green Manure Yield of Crimson Clover (Trifolium incarnatum L.) in Upland Soil

Crimson clover, a legume crop, is a landscape crop and green manure crop that can be sowing in spring and autumn. Its red flower blooms in May, and serves various roles such as landscape composition, weeds suppressing, prevention of soil loss and nutrient on sloping land and supplying nitrogen and organic matter in soil. Thus, in order to utilize this crop in agriculture land, we evaluated the growth characteristics of crimson clover cultivated in four different soil textures; sand, sandy loam, loam, and clay loam. The nitrogen content of crimson clover was 15.8 g kg-1 and C/N ratio was 20.3. Its plant height was 42.5 cm in sandy loam and 49.5 cm in loamy, respectively, approximately 20 cm longer than the sand and clay loam. The crimson clover in sandy loam and loam bloomed about seven days earlier than those in sand and clay loam. Regarding number of flower per hill and flower length, there were no difference among the soil textures. Dry weight of crimson clover for sandy loam and loam was 2.5 Mg ha-1 and 2.3 Mg ha-1, respectively, 0.8 ~ 1.1 Mg ha-1 higher than that of sand and sandy loam. Plant height and dry weight of crimson clover increased with delaying harvest time. Nitrogen contribution in loam and clay loam was 51.3 kg ha-1 and 53.5 kg ha-1, respectively. Therefore, in terms of flowering properties and dry weight, the proper soil texture for the growth and development of crimson clover was sandy loam and loam. The Dry weight of crimson clover as affected by soil texture in upland soil.

Spatial and seasonal dynamics of soil loss ratio in mountain rangelands of south-western Kyrgyzstan

Vegetation cover is the main factor of soil loss prevention. The C-factor of the RUSLE (Revised Universal Soil Loss Equation) was predicted with NDVI, ground data and exponential regression equation for mountain rangelands of Kyrgyzstan. Time series of C-factor, precipitation and temperature were decomposed into seasonal and trend components with STL (seasonal decomposition by loess) to assess their interrelations. C-factor, precipitation and temperature trend components indicated significant lagged correlation, whereas seasonal components indicated more complex relations with climate factors which can be promoting as well as limiting factors for vegetation development, depending on the season. Rainy springs and hot summers may increase soil loss dramatically, whereas warm and dry springs with rainy summers can decrease it. Steep slopes indicated higher soil loss ratio, whereas flat areas were better protected by vegetation.

The effects of Rubus hyrcanus L. and Philonotis marchica (Hedw.) Brid. on soil loss prevention from cutslopes of a forest road

The effects of Rubus hyrcanus L. and Philonotis marchica (Hedw.) Bridon on runoff generation and soil loss from cutslopes of forest roads were investigated. The study was conducted at the northern forest of Iran, about 30 km south of the city of Sari. Runoff and sedimentation after each rainfall simulation and chemical and physical soil properties were measured in 14 plots with an area of 0.48 m<sup>2</sup>. The obtained results indicate that the vegetation dominated by Philonotis marchica exhibited the higher runoff coefficient and soil loss, with averages of 27.25% and 92.40 g·m<sup>–2</sup>·h<sup>–1</sup>(gram per square meter per hour), respectively, in comparison to Rubus hyrcanus. For Philonotis marchica (Hedw.) Brid. the sediment concentration increased quickly at the beginning of rainfall simulations and after 10–12 min there was a fast decrease in sediment concentration. The peak of sediment concentration was for the Rubus hyrcanus L. in the 13<sup>th</sup>–15<sup>th</sup> min In conclusion, Rubus hyrcanus L. prevented or decreased the risk of runoff and soil loss from cutslopes of forest roads in our study area.  

Fluvial landscape models and catchment-scale sediment transport

The need for the ability to make quantitative predictions regarding the transport of sediment within watersheds and from watersheds to the sea has never been more important than it is today. Sediment transport is at the heart of a surprising number of practical problems, ranging from the prevention of soil loss to the tracking of contaminants, and this has resulted in a rich but scattered literature. In many of these contexts, observational data has been used to develop empirical sediment transport laws. For example, the Revised Universal Soil Loss Equation (RUSLE) has been developed for use at the farm-plot scale, and the equation of Syvitski et al. [Water Resour. Res. 36(9) (2000) 2747] was developed for the world's largest river basins. In the context of fluvial geomorphology, several different but closely related sediment transport laws have been used to construct fluvial landscape models. The sediment transport formulas used by these models are a generalized form of several physically based bed-load transport formulas. Based on studies of fluvial landscape models, we now know that many measurable attributes of channelized landscapes, such as junction angles, Horton ratios, hydraulic geometry exponents, valley geometry, and longitudinal profiles, vary in a predictable manner with a few well-constrained, physical parameters. One important consequence of this success in forward modeling is that it is now feasible to solve the inverse problem of calculating regional sediment transport parameters from measurements (such as long profiles) that can easily be made from digital elevation models (DEMs). This may also make it possible to make a rational selection between alternate sediment transport laws. Since fluvial landscape models represent the state of the art in catchment sediment transport modeling, the three-fold purpose of this paper is to: (1) explain the key concepts and simplifying assumptions that are common to these models; (2) explain how several current models differ from one another; and (3) highlight a few of the significant results that have been obtained in recent years. While serving mostly as an expository or overview paper, some new results for a steady state fluvial landscape model are also included.

Effects of Pot Size, Soil Type, and Sodium Alginate Application on the Soil Prevention Rate at the Transplanting of Tea Cuttings Grown in Paper Pots.

チャのペーパーポット(無底)を用いた育苗では,挿し木苗の移植時におけるポットからの挿し土の崩壊・脱落を防ぎ,ポット内に残る挿し土の割合(挿し上保持率)を高める必要がある.本報では,ポットの大きさ,アルギン酸ナトリウム処理及び挿し土の種類が挿し土保持率に及ぼす影響を検討した.その結果,内径の小さなポットで挿し土保持率が高かった.アルギン酸ナトリウム0.3%溶液をポット(内径6cm,深さ15cm)当たり80mL以上処理することで挿し土の固着化が進み,保持率を80～90%以上に高めることができ,その効果は,処理後無潅水で育苗することにより持続した.また,挿し土の種類ごとに挿し上保持率は異なり,砂質土あるいは赤黄色土にピートモスやもみがらくん炭を混合したもので高かった.これら9種類の挿し土にアルギン酸ナトリウムを処理した結果,いずれの挿し土でも保持率は高まったが,その効果の程度は挿し土の種類により異なった.