Conservation management decreases surface runoff and soil erosion

Conservation management practices – including agroforestry, cover cropping, no-till, reduced tillage, and residue return – have been applied for decades to control surface runoff and soil erosion, yet results have not been integrated and evaluated across cropping systems. In this study we collected data comparing agricultural production with and without conservation management strategies. We used a bootstrap resampling analysis to explore interactions between practice type, soil texture, surface runoff, and soil erosion. We then used a correlation analysis to relate changes in surface runoff and soil erosion to 13 other soil health and agronomic indicators, including soil organic carbon, soil aggregation, infiltration, porosity, subsurface leaching, and cash crop yield. Across all conservation management practices, surface runoff and erosion had respective mean decreases of 67% and 80% compared with controls. Use of cover cropping provided the largest decreases in erosion and surface runoff, thus emphasizing the importance of maintaining continuous vegetative cover on soils. Coarse- and medium-textured soils had greater decreases in both erosion and runoff than fine-textured soils. Changes in surface runoff and soil erosion under conservation management were highly correlated with soil organic carbon, aggregation, porosity, infiltration, leaching, and yield, showing that conservation practices help drive important interactions between these different facets of soil health. This study offers the first large-scale comparison of how different conservation agriculture practices reduce surface runoff and soil erosion, and at the same time provides new insight into how these interactions influence the improvement or loss of soil health.     

紫色土坡耕地土壤物理性质空间变异对土壤侵蚀的响应

为了研究不同坡度和坡长的耕地上土壤侵蚀对土壤物理性质空间变异的影响,通过地形测量、137 Cs示踪、土壤物理性质分析等方法对川中丘陵紫色土区土壤物理性质对土壤侵蚀的响应进行了研究,结果表明：在中等坡度（16.60%～25.10%）的梯坡地上,耕作侵蚀处于主导地位,是导致耕层土壤物理性黏粒含量和容重在梯坡地上总体差异不大（CV＜6.3%）,且与137Cs含量不相关的主要原因;在已退耕还林的陡梯坡地上（35.60%）,水蚀占据主导地位,导致耕层土壤物理性黏粒含量和容重均与137Cs的含量显著相关。在长坡耕地上(10.10%),具有分选搬运能力的水力侵蚀占据主导地位,致使耕层土壤物理性黏粒含量与137Cs的含量具有显著的相关关系,而容重却与137Cs含量没有显著的相关关系。川中丘陵区坡耕地上,耕作侵蚀和水蚀共同作用于土层深度,使土层深度在坡顶、上坡最浅,在坡脚最深,顺坡向下逐渐增加。因此,在川中丘陵区不同坡长的坡耕地上,占主导地位的土壤侵蚀类型导致坡耕地上土壤物理性质出现相应的变化。     

新型土壤侵蚀磁性示踪剂的研制及其对土壤理化性状的影响

我国水土流失日益严重,已成为制约构建和谐社会的重大生态环境问题[1]。因此,土壤侵蚀的监测研究显得格外重要且十分紧迫。磁性示踪技术作为土壤侵蚀监测研究的一种新手段,具有很多优点[2-3],近年来逐渐得到广大科研工作者的重视。     

Rock fragments I. Their effect on runoff, erosion and soil properties under field conditions

Abstract. The effects of different sizes, amounts, and positions of rock fragments on soil properties and erosion were studied in experimental plots (10 treatments including bare soils and soils under natural vegetation, with 3 replicates each) installed on a hillslope.
Over five events, the largest amounts of runoff were from bare soils containing abundant rock fragments, either partially embedded on the surface or incorporated in the upper part of the soil. Stoneless soils gave smaller amounts, and the smallest runoffs were measured on soils under natural vegetation. Generally, large rock fragments (cobbles) caused greater runoff than smaller fragments (coarse gravel). However, soils with appreciable amounts of coarse gravel on the surface generated considerable runoff under rainfalls of low intensity and long duration, but smaller amounts at greater rainfall intensities.
Sediment loss was greater from soils with cobbles than from soils containing coarse gravel; vegetation greatly decreased sediment loss from both.
In a 12-month period, the organic matter content of the soils decreased by 15.5 to 23.0%, decreasing soil aggregate stability. The organic matter content was greater in the collected sediments than in the soil.     

Rainfall/runoff/erosion relationships and soil properties survey in abandoned shallow soils of NE Spain

Purpose

Shallow soils previously cultivated under terraced systems may change their properties after agricultural release and spontaneous plant colonization. Investigations were conducted in terraced fields (NE Spain) to prove that vegetation installed after the abandonment may generally improve soil properties by the formation of stable organic horizons. However, restriction in plant species along the natural vegetation succession and intensification of erosion processes may occur after abandonment depending on fire frequency and soil use history.

Materials and methods

Ten environments with different plant covers under a Lithic Xerorthent were selected and erosion plots (Gerlach type) installed providing their best adaptability at the terrace scale. Selected soil environments represented the sequence of abandonment: from current poorly cultivated soils, soils under pasture, soils under shrubs, and soils under stands of pine and cork trees. Relevant rainfall events producing runoff and erosion were recorded from November 2011 to May 2012. Erosion rates and erosion components were analysed in sediments and water in order to monitor carbon, nitrogen and other nutrient removal by overland flow. Similarly, the physical and chemical properties of the soil environments under study were determined at the same time interval of runoff erosion.

Results and discussion

Soils under pasture, vines and recently burnt pine forest produced the highest runoff followed by soils under shrubs and forest. However, eroded soil yields and nutrient removal were much higher in cultivated soils and soils in recently burnt sites, which had shown poorer soil properties with respect to soils abandoned for longer and preserved by fire. Fire-affected soil environments also showed a thinner organic horizon and reduced water retention. Although erosion rates and nutrient depletion were low in all environments with respect to other areas of Spain, higher splash than water erosion was an early warning indicator of the high susceptibility to degradation of these shallow soils.

Conclusions

Results outlined that the renaturalization dynamics after agricultural abandonment are complex biophysical processes involving the parent material, depth to bedrock and other soil properties as well as the succession of vegetative cover and plant associations responsible for building a new soil mantle contrasting with erosion processes. Planning for management of land abandonment is strongly recommended.

     

Effects of mulching on soil physical properties and runoff under semi-arid conditions in southern Spain

Application of crop residues to soil and reduced or no tillage are current management practices in order to achieve better water management, increase soil fertility, crop production and soil erosion control. This study was carried out to quantify the effect of wheat straw mulching in a no tilled Fluvisol under semi-arid conditions in SW Spain and to determine the optimum rate in terms of cost and soil protection. After a 3-years experiment, mulching application significantly improved physical and chemical properties of the studied soil with respect to control, and the intensity of changes was related to mulching rate. The organic matter content was generally increased, although no benefit was found beyond 10 Mg ha⁻¹ year⁻¹. Bulk density, porosity and aggregate stability were also improved with increasing mulching rates, which confirmed the interactions of these properties. Low mulching rates did not have a significant effect on water properties with respect to control, although the available water capacity increased greatly under high mulching rates. After simulated rainfall experiments (65 mm h⁻¹ intensity), it was found that the mulch layer contributed to increase the roughness and the interception of raindrops, delaying runoff generation and enhancing the infiltration of rain water during storms. Mulching contributed to a reduction in runoff generation and soil losses compared to bare soil, and negligible runoff flow or sediment yield were determined under just 5 Mg ha⁻¹ year⁻¹ mulching rate. It was observed that during simulations, the erosive response quickly decreases with time after prolonged storms (30 min) due to the exhaustion of available erodible particles. These results suggest that the erosive consequences of intermediate intensity 5-years-recurrent storms in the studied area could be strongly diminished by using just 5 Mg ha⁻¹ year⁻¹ mulching rates.     

Cropping systems and bed width effects on runoff,erosion and soil properties in a rainfed Vertisol

The effects of two bed widths (1 and 2 m) and four rainfed cotton‐based cropping systems on soil properties, runoff and erosion were evaluated in a Vertisol (1 per cent slope; 21 g per 100 g sand, 12 g per 100 g silt, 67 g per 100 g clay) in subtropical central Queensland, Australia. The cropping systems were: early cotton (Gossypium hirsutum L.) sown between August and October; wheat (Triticum aestivum L.) sown in May, sprayed out and followed by early cotton; wheat allowed to mature, harvested and followed by late cotton sown between October and December; and grain sorghum (Sorghum bicolor (L.) Moench.) followed by cotton. Land preparation was by minimum tillage and traffic was restricted to the furrows between the beds. Rainfall runoff and soil erosion were monitored with water‐height recorders, flumes and troughs. Soil structure was evaluated as air‐filled porosity of oven‐dried soil in the 0–0.15, 0.15–0.30, 0.30–0.45 and 0.45–0.60 m depths. Soil chemical properties measured in the 0–0.15 m depth were organic carbon, pH (in 0.01 M CaCl₂), electrical conductivity (EC_1:5) of a 1 : 5 soil : water suspension and exchangeable Ca, Mg, K and Na. In comparison with 1 m beds, 2 m beds resulted in lower runoff and soil erosion, lower exchangeable Na, exchangeable sodium percentage and higher EC_1:5/exchangeable Na, higher rate of soil organic matter decrease and better soil structure in the 0–0.15 m depth. Runoff and erosion were reduced, and cotton lint yields increased either by cropping systems sown early to intercept most of the seasonal rainfall or by those which produced a high level of ground cover. Soil physical and chemical properties were best, and runoff and erosion lowest with 2 m beds and cropping systems producing a high level of ground cover. Copyright © 2002 John Wiley & Sons, Ltd.     

Estimation of runoff critical shear stress for soil erosion from soil shear strength

Critical shear stress is an important soil parameter governing detachment by runoff which appears in numerous erosion models. Soil shear strength has been often presented as the best soil property to predict critical shear stress. However, only a few studies have documented the relationship between soil shear strength and critical shear stress, and the results obtained have sometimes seemed contradictory. This is why we have put together all available data about the relationship between critical shear stress and soil shear strength in order to analyse and discuss its significance and its generality. Results showed that contradictions between different studies mainly arise because total shear stress is a poor predictor of detachment on rough soils. When grain shear stress is used rather than total shear stress, a significant relationship between saturated soil shear strength and critical shear stress does exist. Soil shear strength may thus be used to predict critical grain shear stress. However, it is recalled that in general only total shear stress is predicted by erosion models, which makes detachment predictions difficult on rough natural soils.     

Direct and indirect effects of Mediterranean vegetation on runoff and soil loss

Vegetation cover acts in a complex way in influencing runoff and soil loss and a great deal of information is needed to model these effects. In the Mediterranean, the abandonment of land is important under extensive land‐use. Abandoned lands typically have a rolling landscape with steep slopes, and are dominated by herbaceous communities that grow on pasture land interspersed by shrubs. To characterize communities of vegetation such as these, which grow in central Spain, and to evaluate their direct and indirect effects on runoff and soil loss, we carried out experiments with simulated rain. We assessed separately the effects of pasture land and of four species of shrubs (Dorycnium pentaphyllum Scop., Medicago strasseri Greuter et al., Colutea arborescens L. and Retama sphaerocarpa, L.). The infiltration rates under herbaceous vegetation were 7.9 times greater than those obtained on bare land (92.2 mm hour⁻¹ compared with 11.7 mm hour⁻¹), and 88% of these differences could be attributed to direct effects. On the pasture land, as the proportion of covered land increased, the runoff decreased linearly, whereas the soil loss decreased exponentially. On the land covered by shrubs, the average infiltration rate was 82.5 mm hour⁻¹. Under D. pentaphyllum and M. strasseri infiltration rates were greater than 105 mm hour⁻¹, whereas for R. sphaerocarpa the infiltration rate was 57 mm hour⁻¹. For D. pentaphyllum and M. strasseri soil loss was less than 4.5 g m⁻², whereas for C. arborescens soil loss was 61.4 g m⁻². Unlike the results for the pasture land, for the shrub‐type vegetation the increases in infiltration rates could be attributed to indirect effects: they explained 47% of the increase in infiltration for C. arborescens, 69% for R. sphaerocarpa, 75% for D. pentaphyllum and 100% for M. strasseri.     

Effects of soil crust and crop on runoff and erosion in Loess Plateau

Soil crust formed after rainfall has a strong influence on soil erosion, water use, and crop growth on sloping farmland. To study the effect of soil crust on sloping farmland on runoff amount and erosion sediment yield, the soil crust on sloping farmland has been studied in this paper for plantings of corn, soybeans, millet, and winter wheat. Using an outdoor rainfall simulator, the influence of soil crust on runoff rate and sediment yield on sloping farmland covered by crops has been observed. The results revealed that soil crust thickness was increased after rainfall and soil crust coverage showed little change after rainfall. Soil crust had a significant impact on runoff and sediment yield on sloping farmland. Slopes with soil crust showed higher runoff rate and less soil loss than slopes without soil crust. On slopes planted with four crops (corn, soybeans, millet, and winter wheat), runoff rates on slopes with soil crust were respectively 20%, 25%, 25%, and 21% higher than on slopes without soil crust; sediment yield on slopes with soil crust was respectively 15%, 14%, 14%, and 8% lower than on slopes without soil crust. Crops enlarged the runoff difference between the two kinds of slope and decreased the sediment yield difference between them. Crop growth enhanced these differences in runoff and sediment yield between slopes with and without soil crust.     

Residue impacts on runoff and soil erosion for different corn plant populations

The year to year carry-over effects of biomass additions under different plant populations on runoff and erosion are unclear. The objective of this study was to quantify the impact of different plant populations on residue cover to elucidate the effects of residue cover on runoff and erosion. The residue management system involved shredding of corn (maize) biomass after harvest, incorporating the residue in the spring, and leaving the land fallow until it was no-till planted the following spring. Runoff and soil losses were measured on 18 runoff plots with plots arranged in two areas with each having three randomized treatments (0%, 50%, and 100% plant population) with three replications. The two areas were managed as a fallow/no-till corn rotation in two cycles of alternating years. Surface residue cover was highly dynamic with significant changes between cycles and seasons in response to the management practices. The annual soil losses were reduced by 47% and 54% for the 50% and 100% plant populations, respectively compared to the control. However, the annual soil loss even for the 100% plant population was still nearly seven times the tolerable soil loss limit of 7 ton ha⁻¹. The normal erosion protection afforded by no-till practices was lost by the incorporation of residue the previous year.     

The effect of urban refuse compost and different tractors tyres on soil physical properties, soil erosion and maize yield

Application of urban refuse compost to agricultural soil could help to solve municipalities' problems related to the increasing production of waste only if soil property improvement and environmental conservation can be demonstrated. The use of low-pressure tractor tyres is another proposal in modern agriculture for reducing soil compaction. This study thus aimed to detect the effects of both compost and low-pressure tractor tyres on soil loss, runoff, aggregate stability, bulk density, penetrometer resistance and maize (Zea mays L.) yield. A 3-year field experiment was carried out on a hilly (15% slope) clay loam soil in central Italy. Twelve plots (200 m² each) were monitored with tipping-pot devices for runoff and soil erosion measurement. Treatments were: compost addition (64 Mg ha⁻¹), mineral fertilisation, use of low-pressure tyres, use of traditional tyres, with three replicates, in a fully randomised block design. Compost was applied once at the beginning of the experiment. Runoff reduction due to compost ranged between 7 and 399 m³ ha⁻¹ during seasons, while soil erosion was reduced between 0.2 and 2.4 Mg ha⁻¹. Mean weight diameter (MWD) of stable aggregates, measured on wheel tracks, increased by 2.19 mm, then progressively decreased. Compost significantly increased bulk density by 0.08 Mg m⁻³ due to its inert fraction content. This effect was less evident in the second and third year, probably due to harrowing. Maize yields were slightly, but significantly, reduced in composted plots by 1.72 Mg ha⁻¹ in the third year. Low-pressure tyres significantly reduced soil loss in the third year by 1 Mg ha⁻¹. Furthermore, they did not significantly influence runoff volumes and soil structural stability. Low-pressure tyres or compost addition were singly able to prevent an increase in penetrometer resistance due to agricultural machinery traffic. Low-pressure tyres increased the maize yield during the 3 years and the difference (0.4 Mg ha⁻¹) became significant in the third year. In conclusion, results show the positive lasting effect of compost in ameliorating soil physical properties and reducing runoff and soil erosion. Low-pressure tyres appear justifiable both for the observed increase of grain production and reduction of soil compaction. This latter effect is, nevertheless, masked by compost addition which is also able to reduce penetrometer resistance. Further research is required to explain the causes of the slight inhibition of grain yield observed when compost was compared with mineral fertilisation.     

Interactions between soil properties and moisture content in crust formation, runoff and interrill erosion from tilled loess soils

Soil-surface seals and crusts resulting from aggregate breakdown reduce the soil infiltration rate and may induce erosion by increasing runoff. The cultivated loess areas of northwestern Europe are particularly prone to these processes.Surface samples of ten tilled silty loamy loess soils, ranging in clay content from 120 to 350 g kg⁻¹ and in organic carbon from 10 to 20 g kg⁻¹, were packed into 0.5 m² plots with 5% slopes and subjected to simulated rainfall applied at 30 mm h⁻¹. The 120 minutes rainfall events were applied to initially field-moist soil, air-dried soil and rewetted soil to investigate the effect of soil moisture content prior to rainfall. Runoff and eroded sediments were collected at 5 minutes intervals. Aggregate stability of the soils was assessed by measuring particle-size distribution after different treatments.All soils formed seals. Runoff rates were between 70 and 90% by the end of the rainfall event for field-moist plots. There were large differences between soil runoff rates for the air-dried and rewetted plots. Interrill erosion was associated with runoff, and sediment concentration in runoff readily reached a steady-state value. Measurements of aggregate stability for various treatments were in good agreement with sealing, runoff and erosion responses to rainfall. Runoff and erosion were lower for air-dried plots than for field-moist plots, and were either intermediate or lowest for rewetted plots, depending on soil characteristics. Soils with a high clay content had the lowest erosion rate when they were rewetted, whereas the soil with a high organic-carbon content had the lowest erosion rate in air-dry conditions. The results indicate the complexity of the effect of initial moisture content, and the interactions between soil properties and climate.     

Effects of rock fragment cover on soil infiltration, interrill runoff and erosion

Considerable attention has been paid recently to the influence of surface rock fragments on hydrological and erosional processes, although much of this research has been done on disturbed soils under laboratory conditions. I have studied the effects of rock fragments on soil infiltration, runoff and erosion under field conditions using simulated rainfall on bare areas of natural soils within typical Mediterranean scrubland characterized by patchily distributed vegetation. Sample areas were chosen where rock fragments cover more than half the surface within unvegetated patches. Twenty experiments were carried out by applying rain at an intensity of 55 mm h^?1 for 60 minutes. This approach shows that rock fragments (i) retard ponding and surface runoff, and (ii) give greater steady‐state infiltration rates and smaller interrill runoff discharges, sediment concentrations and interrill erosion rates. A second set of six experiments was carried out by applying rainfall at an intensity of 55 mm h^?1 for two runs of 60 minutes. The second run was initiated 10 minutes after the first. During this interval, surface rock fragments were removed in order to measure their effects on infiltration, interrill runoff and erosion rates. In this way, I showed that water and soil losses are reduced by the rock fragments. After the removal of rock fragments the steady‐state infiltration rate diminished from 44.5 to 27.5 mm h^?1 and the runoff coefficient, sediment concentration and erosion rates were, respectively, 3, 33 and 39 times greater than they were before the rock fragments were removed.     

坡地开垦的径流泥沙响应

Land use and land cover change is a key driver of environmental change. To investigate the runoff and erosion responses to frequent land use change on the steep lands in the Three Gorges area, China, a rainfall simulation experiment was conducted in plots randomly selected at a Sloping Land Conversion Program site with three soil surface conditions: existing vegetation cover, vegetation removal, and freshly hoed. Simulated rainfall was applied at intensities of 60 (low), 90 (medium), and 120 mm h 1 (high) in each plot. The results indicated that vegetation removal and hoeing significantly changed runoff generation. The proportion of subsurface runoff in the total runoff decreased from 30.3% to 6.2% after vegetation removal. In the hoed plots, the subsurface runoff comprised 29.1% of the total runoff under low-intensity rainfall simulation and the proportion rapidly decreased with increasing rainfall intensity. Vegetation removal and tillage also significantly increased soil erosion. The average soil erosion rates from the vegetation removal and hoed plots were 3.0 and 10.2 times larger than that in the existing vegetation cover plots, respectively. These identified that both the runoff generation mechanism and soil erosion changed as a consequence of altering land use on steep lands. Thus, conservation practices with maximum vegetation cover and minimum tillage should be used to reduce surface runoff and soil erosion on steep lands.     

A modification for the theoretical infiltration equations based on physical properties of the soil

A modification based on capillary flow type was proposed for three theoretical infiltration equations accounting for the physical properties of the soil. The equations were (a) Green and Ampt, (b) Fletcher, and (c) Fok and Hansen. The derived modified equations were tested by computer programs on four undisturbed field soils on which the mass infiltration and soil properties had been measured. Of the three equations, (b) exhibited the best adherence to the data points and (a) and (c) were reasonably good. In general, the types of relations revealed by the field measurements were such as would tend to linearize if the log of the mass infiltration was plotted against the log of time. The breaks exhibited by some of the soils could be explained by changes in the soil properties at that point.     

由降雨事件引起的坡面产流和土壤侵蚀的元胞自动机模拟

A novel quantitative cellular automata (CA) model that simulates and predicts hillslope runoff and soil erosion caused by rainfall events was developed by integrating the local interaction rules and the hillslope surface hydraulic processes. In this CA model, the hillslope surface was subdivided into a series of discrete spatial cells with the same geometric features. At each time step, water and sediment were transported between two adjacent spatial cells. The flow direction was determined by a combination of water surface slope and stochastic assignment. The amounts of interchanged water and sediment were computed using the Chezy-Manning formula and the empirical sediment transport equation. The water and sediment discharged from the open boundary cells were considered as the runoff and the sediment yields over the entire hillslope surface. Two hillslope soil erosion experiments under simulated rainfall events were carried out. Cumulative runoff and sediment yields were measured, respectively. Then, the CA model was applied to simulate the water and soil erosion for these two experiments. Analysis of simulation results indicated that the size of the spatial cell, hydraulic parameters, and the setting of time step and iteration times had a large impact on the model accuracy. The comparison of the simulated and measured data suggested that the CA model was an applicable alternate for simulating the hillslope water flow and soil erosion.     

Surface runoff and soil erosion in a natural regeneration area of the Brazilian Cerrado

The Brazilian Cerrado has been converted to farmland, and there is little evidence that this expansion will decrease, mainly because agriculture is the country’s main economic sector. However, the impacts of intense modification of land use and land cover on surface runoff and soil erosion are still poorly understood in this region. Here, we assessed surface runoff and soil loss in a woodland Cerrado area under a former pasture area, which was abandoned and has undergone a natural regeneration process for 7 years (RC). Its results were compared with that found in an undisturbed area of woodland Cerrado (CE), 40-month-old eucalyptus (3.0 × 1.8 m) (EU), and pasture under rotational grazing (PA). The study was conducted on Red Acrisol located in the Brazilian Cerrado. We performed rainfall simulations on a plot of 0.7 m² and using three constant rainfall intensities of 60, 90, and 120 mm h⁻¹ for 1 h. For each rainfall intensity, we carried out four repetitions using different plots in each treatment, i.e. 12 plots per treatment studied and 48 plots in total. We noted that the soil physical properties were improved in RC and, consequently, water infiltration and soil erosion control; RC presented surface runoff and soil loss different from EU and PA (α = 0.05). The macroporosity and soil bulk density affected surface runoff in RC and PA because the RC was used as pasture and is currently regenerating back to the cerrado vegetation. As the rainfall intensity increased, EU became more similar to PA, which showed the highest surface runoff and soil loss. Our findings indicate that natural regeneration processes (pasture to the cerrado vegetation) tend to improve the soil ecosystem services, improving infiltration and reducing surface runoff and soil erosion.     

Modification of a rainfall simulation procedure at runoff plots for soil erosion investigation

A modification of a rainfall simulation procedure at runoff plots for the study of erosion is suggested. It is based on the (1) physically substantiated erosion parameter of simulated rainfall A, (2) the new erosion index for natural rains AI derived from the erosion parameter A, and (3) USLE and RUSLE equations. To simplify the testing procedure and interpretation of the measured data, we use rainfall of permanent intensity I, drop size, and rainfall velocity V. To study the influence of any factor (or their combination) on the soil loss, the experiment was performed at several runoff plots, one of which was a control (fallow soil, and soil tillage performed along the slope). According to the measurement results, a graph of the dependence between the cumulative soil loss and the AI index was compiled that fits the linear regression equation. Thus, the derived equations are also valid for natural rains. The critical values of AI _cr upon which the runoff and soil loss start are determined from these equations. The soil erodibility factor is calculated from the equation obtained for the control plot using the relief factor of the RUSLE equation. The influence of the studied factors on soil erosion is assessed from the comparison of equations obtained for the appropriate sites and the control. Upon the infiltration study, the water discharge is measured until its stabilization, when the steady infiltration velocity is reached. The following investigation results are cited as examples: (1) the influence of the initial soil moisture, the soil mulching with straw, and the plant cover on the soil loss; (2) application of the obtained experimental data for assessing the average annual soil loss from natural rains; and (3) the relationship between the infiltration and the rainfall erosivity index AI.