Soil organic carbon and nutrients losses form the sloping land in the scenario of water erosion in the south of Rwanda

2020 ◽  
Author(s):  
Baiqun Wang ◽  
Chaodong Li ◽  
Zhanbin Li
Keyword(s):  
Soil Erosion ◽  
Organic Carbon ◽  
Water Erosion ◽  
Nutrient Losses ◽  
Sloping Lands ◽  
Sloping Land ◽  
Erosive Rainfall ◽  
Sloping Farmland ◽  
Soil And Water ◽  
Runoff Plot

<p><strong>Abstract:</strong>Rwanda is located in the plateau of the central-eastern Africa nearby the equator of the Earth, known as ’The Land of a Thousand Hills’, and covers the part of the region of the Upper Nile. The sloping lands are ubiquitous across Rwanda, and the sloping farmlands account for more than 70 per cent of the sloping land resources. The soil and water losses are very severe on the sloping lands, especially on the sloping farmlands due to the farming activities and soil water erosion induced by the erosive rainfall events. Therefore, the soil erosion and soil organic carbon (SOC) and nutrient losses and the resultant soil deterioration and crop yield decline on the sloping farmlands in this country have attracted the widespread concerns. It is necessary to understand severity of the SOC and nutrient losses on the sloping farmland due soil erosion in term of launching the countermeasure to control the losses. The investigation on the SOC and nutrient losses in the sloping farmlands and the rainfall was carried out on the runoff plot with 20m long, 5m wide and gradient of 12°in Rubona, Huye District, south province of Rwanda. The cropping rotation of soybean-maize-groundnut was practiced on the plot during the monitor on soil losses from the plot. The contents of constituents of soils lost from the plot decreased in the order: SOC> total potassium (TK)>total nitrogen (TN)>total phosphorus (TP). The loss intensities of SOC from the plot varied from 383.0 kg/hm<sup>2</sup> to 1680.9 kg/hm<sup>2</sup> in the period from 2011 to 2013, 259.4 kg/hm<sup>2</sup> to 1138.5 kg/hm<sup>2</sup> for TK, 41.2 kg/hm<sup>2</sup> to 180.8 kg/hm<sup>2</sup> for TN, 9.2 kg/hm<sup>2</sup> to 40.2 kg/hm<sup>2</sup> for TP. The loss intensities of SOC, TK, TN and TP were 1262.3 kg/hm<sup>2</sup>, 99.0 kg/hm<sup>2</sup>, 99.4 kg/hm<sup>2</sup>, 35.4 kg/hm<sup>2</sup> in 2017, and 3786.8 kg/hm<sup>2</sup>, 2970.0 kg/hm<sup>2</sup>, 298.1 kg/hm<sup>2</sup> and 106.3 kg/hm<sup>2</sup> in 2018, respectively. The loss intensities of SOC and nutrients varied significantly over the years. It can be seen that the amounts of erosive rainfall have the crucial impacts on loss intensities of SOC and nutrients through analyzing the relation between loss intensities and erosive rainfall. The relations between loss intensities of SOC and nutrients and mounts of erosive rainfall can be described by exponential function. Compared with the loss intensities of SOC and nutrients on the runoff plot, the loss intensities were much less on the plots with the corresponding soil and water conservation measures such as terracing and plant hedges. Therefore, the measures of anti-erosion should be adopted on the sloping farmlands in an effort to reduce SOC and nutrient losses and keep the sustainable soil productivity in Rwanda. </p><p><strong>Keywords:</strong> SOC; nutrient; sloping farmland, Rwanda</p>

Management-induced soil water erosion and nutrient losses in different land use in Mediterranean environment

2020 ◽  
Author(s):  
Igor Bogunovic ◽  
Leon Josip Telak ◽  
Paulo Pereira
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Soil Properties ◽  
Soil Water ◽  
Water Erosion ◽  
Rainfall Simulation ◽  
Soil Tillage ◽  
Conservation Strategies ◽  
Nutrient Losses ◽  
Olive Orchard

<p>Soil erosion by water is one of the most important degradation processes. Land use has important effects on soil properties, therefore it is key to identify the type of management that have more impacts and find solutions to mitigate it. In order to understand the effects of land use management on soil and soil erosion in the Istria region (Croatia), we studied the impacts of different agriculture practices (vineyard, cropland, and olive orchard) on soil properties and runoff. The simulated rainfall was carried out at 58 mm h<sup>−1</sup> in the summer of 2018 (30% soil water content) for 30 min on 0.785 m<sup>2</sup> circular plots. The results showed that bulk density was significantly higher in cropland plots than in the vineyard and olive orchard. Soil organic matter, mean weight diameter, and aggregate stability were significantly higher in olive orchard plots than in the vineyard and cropland. Runoff and sediment losses were higher in olive orchard compared to vineyard plots. Carbon, nitrogen, and phosphorus losses were highest in olive orchard plots with 3.9 kg ha<sup>-1</sup>, 405.2 g ha<sup>-1</sup> and 73.6 g ha<sup>-1</sup>, respectively, while lower values were measured in the vineyard plots, where nutrients losses were lower with 0.9 kg ha<sup>-1</sup>, 73.8 g ha<sup>-1</sup> and 6.5 g ha<sup>-1</sup>, respectively. No runoff was observed in cropland plots. Even with the highest measured values of runoff and erosion in the herbicide treated olive orchard, results indicate that both herbicide application and tillage represent a threat to the sustainability of Istrian soils. Vegetation cover on cropland reduces the runoff generation indicating the need for adoption of conservation strategies. In current management, vegetation removal should be avoided since it contributes to practice to reduce nutrient losses and increase the sustainability of the soils.</p><p> </p><p><strong>Keywords</strong>: Soil water erosion, Soil tillage, Rainfall simulation, Agriculture land management, Mediterranean</p><p> </p><p><strong>Acknowledgements</strong></p><p> </p><p>This work was supported by Croatian Science Foundation through the project "Soil erosion and degradation in Croatia" (UIP-2017-05-7834) (SEDCRO).</p>

Soil erosion leads to significant mobilisation of terrestrial organic and inorganic carbon

2020 ◽  
Author(s):  
Laura Turnbull ◽  
John Wainwright
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Degradation ◽  
Inorganic Carbon ◽  
Dust Emission ◽  
Water Erosion ◽  
Land Use Systems ◽  
Erosion Rates ◽  
Soil Erosion Rates

<p>Soil carbon content is greatly affected by soil degradation – in particular erosional processes – which cannot be ignored in the context of the global C cycle. Soil degradation, driven largely by wind and water erosion, affects up to 66% of Earth’s terrestrial surface. Understanding how soil degradation affects soil organic carbon (SOC) and soil inorganic carbon (SIC) stocks is an essential component of understanding global C cycling and global C budgets, and is essential for improved C management and climate-change mitigation policies.</p><p>In this study, we quantify the distribution of SOC and SIC, and estimate their combined effects on carbon mobilisation via water and wind-driven erosion. We estimate spatially variable water-driven erosion rates for different land-use systems and degradation severities using values obtained from a meta-analysis of soil erosion rates, and undertake stochastic simulations to account for possible uncertainty in our estimates. For wind-driven soil erosion rates we use modelled dust emission rates from AeroCom Phase III model experiments for the 2010 control year, for 14 different models. We use the Harmonized World Soil Database v1.2 to calculate SOC and SIC stocks, the GLASOD map of soil degradation to estimate soil degradation severities and the Land Use Systems of the World database to estimate water-driven erosion rates associated with different land-use systems.  </p><p>We find that 651 Pg SOC and 306 Pg SIC (in the top 1-m of soil) is located in degrading soils. We estimate global water-driven soil erosion to be 216.4 Pg yr<sup>-1</sup>, which results in the mobilisation of ~2.9536 Pg OC yr<sup>-1</sup>. Accounting for the enrichment of organic carbon in eroded sediment increases these estimates up to 12.2 Pg SOC yr<sup>-1</sup>. A minimum estimate of SIC mobilisation by water erosion is ~0.5592 Pg IC yr<sup>-1</sup>. Dust emission model ensemble results indicate that ~19.8 Pg soil is eroded for the 2010 AeroCom reference year, with ~11.1 Pg deposited via dry deposition and ~7.2  Pg deposited via wet deposition. The total amount of SOC and SIC mobilised by water-driven erosion is greater than wind-driven erosion, and the spatial patterns of SIC and SOC mobilisation by wind and water vary considerably. Across all land-use types, water-driven carbon mobilisation is higher than wind. Water-driven SOC mobilisation is highest in cropland (~ 2.6602 Pg OC yr<sup>-1</sup>) where high erosion rates coincide with average SOC content of 68.4 tonnes ha<sup>-1</sup>. SIC mobilisation follows the same pattern in relation to land use, with highest water-driven mobilisation in cropland (~0.4660 Pg IC yr<sup>-1</sup>) and highest wind-driven mobilisation in bare areas (0.05 Pg IC yr<sup>-1</sup>). Overall, wind-driven erosion mobilises more IC than OC.</p><p>Future land-use change has great potential to affect global soil carbon stocks further, especially with increases in the severity of soil degradation as human pressures on agricultural systems increase.</p>

scholarly journals 137Cs-Based Variation of Soil Erosion in Vertical Zones of a Small Catchment in Southwestern China

2019 ◽  
Vol 16 (8) ◽  
pp. 1371 ◽  
Author(s):  
Jiacun Chen ◽  
Zhonglin Shi ◽  
Anbang Wen ◽  
Dongchun Yan ◽  
Taili Chen
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
High Elevation ◽  
Small Catchment ◽  
Management Measures ◽  
Sloping Land ◽  
The Mean ◽  
Ecological Construction ◽  
Sloping Farmland ◽  
High Elevation Forest

The study of the variability of soil erosion in mountainous areas provides the basis for soil and water conservation work and forest ecological construction in a targeted way. In this study, Liangshan Town catchment, a typical catchment in the Hengduan Mountains region, southwest China, was selected to investigate the variation of soil erosion in different vertical zones using the 137Cs tracing technique. The mean 137Cs reference inventories varied between 573.51 and 705.54 Bq/m2, with the elevation increasing from 1600 to 2600 m. The rates of soil erosion exhibited a significant variation. Under the same land cover condition, the average annual soil erosion modulus of high-elevation forest (elevation > 2200 m) was 400.3 t/(km2·a). However, the average annual soil erosion modulus of a low-elevation sparse forest (elevation < 1600 m) was as high as 1756 t/(km2·a). The average annual soil erosion modulus of the sloping farmland, mainly distributed at elevations of 1600–2200 m, was estimated to be 2771 t/(km2·a). These results indicate that effective soil management measures need to be implemented on the cultivated sloping land in the future.

scholarly journals Lateral transport of soil carbon and land−atmosphere CO2 flux induced by water erosion in China

2016 ◽  
Vol 113 (24) ◽  
pp. 6617-6622 ◽  
Author(s):  
Yao Yue ◽  
Jinren Ni ◽  
Philippe Ciais ◽  
Shilong Piao ◽  
Tao Wang ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Large Scale ◽  
Carbon Sink ◽  
Co2 Flux ◽  
Water Erosion ◽  
Lateral Transport ◽  
Mountainous Regions

Soil erosion by water impacts soil organic carbon stocks and alters CO2 fluxes exchanged with the atmosphere. The role of erosion as a net sink or source of atmospheric CO2 remains highly debated, and little information is available at scales larger than small catchments or regions. This study attempts to quantify the lateral transport of soil carbon and consequent land−atmosphere CO2 fluxes at the scale of China, where severe erosion has occurred for several decades. Based on the distribution of soil erosion rates derived from detailed national surveys and soil carbon inventories, here we show that water erosion in China displaced 180 ± 80 Mt C⋅y−1 of soil organic carbon during the last two decades, and this resulted a net land sink for atmospheric CO2 of 45 ± 25 Mt C⋅y−1, equivalent to 8–37% of the terrestrial carbon sink previously assessed in China. Interestingly, the “hotspots,” largely distributed in mountainous regions in the most intensive sink areas (>40 g C⋅m−2⋅y−1), occupy only 1.5% of the total area suffering water erosion, but contribute 19.3% to the national erosion-induced CO2 sink. The erosion-induced CO2 sink underwent a remarkable reduction of about 16% from the middle 1990s to the early 2010s, due to diminishing erosion after the implementation of large-scale soil conservation programs. These findings demonstrate the necessity of including erosion-induced CO2 in the terrestrial budget, hence reducing the level of uncertainty.

scholarly journals Temporal changes in soil water erosion on sloping vineyards in the Ruwer- Mosel Valley. The impact of age and plantation works in young and old vines

2017 ◽  
Vol 65 (4) ◽  
pp. 402-409 ◽  
Author(s):  
Jesús Rodrigo-Comino ◽  
Christine Brings ◽  
Thomas Iserloh ◽  
Markus C. Casper ◽  
Manuel Seeger ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Sustainable Management ◽  
Soil Loss ◽  
Overland Flow ◽  
Water Erosion ◽  
Management Systems ◽  
Water Losses ◽  
The Impact ◽  
Effect Of Age ◽  
Soil And Water

AbstractIt is well known that rainfall causes soil erosion in sloping German vineyards, but little is known about the effect of age of plantation on soil erosion, which is relevant to understand and design sustainable management systems. In the Ruwer-Mosel valley, young (1- to 4-years) and old (35- to 38-years after the plantation) vineyards were selected to assess soil and water losses by using two-paired Gerlach troughs over three years (2013-2015). In the young vineyard, the overland flow was 107 L m-1and soil loss 1000 g m-1in the year of the plantation, and decreased drastically over the two subsequent years (19 L m-1; 428 g m-1). In the old vineyard, soil (from 1081 g m-1to 1308 g m-1) and water (from 67 L m-1to 102 L m-1) losses were 1.2 and 1.63 times higher, respectively, than in the young vineyard.

scholarly journals Effect of Biochar on Soil and Water Loss on Sloping Farmland in the Black Soil Region of Northeast China during the Spring Thawing Period

2021 ◽  
Vol 13 (3) ◽  
pp. 1460
Author(s):  
Pengfei Yu ◽  
Tianxiao Li ◽  
Qiang Fu ◽  
Dong Liu ◽  
Renjie Hou ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Water Loss ◽  
Water Conservation ◽  
Field Experiments ◽  
Field Capacity ◽  
Application Rate ◽  
Frozen Soil ◽  
Soil And Water Loss ◽  
Sloping Farmland ◽  
Soil And Water

Biochar, as a kind of soil amendment, has attracted wide attention from scholars in various countries, and the effects of biochar on soil and water loss have been well reported. However, soil erosion is significantly affected by geographical conditions, climate, and other factors, and research on the characteristics of soil erosion and the effects of biochar application in seasonally frozen soil areas is currently unclear. The purpose of this study was to explore the effect of corn straw biochar application on soil and water conservation during the spring thawing period. Specifically, through field experiments, the addition of 0, 6, and 12 kg m−2 biochar on slopes of 1.8, 3.6, 5.4, and 7.2° and the effects on runoff and the soil erosion rate of farmland were analyzed. The results showed that in the 6 and 12 kg m−2 biochar addition treatments, the saturated water content of the soil increased by 24.17 and 42.91%, and the field capacity increased by 32.44 and 51.30%, respectively. Compared with the untreated slope, with an increase in biochar application rate, runoff decreased slightly, and soil erosion decreased significantly. This study reveals that biochar can be used as a potential measure to prevent soil and water loss on sloping farmland in cold regions.

Pendampingan pada Petani Mawar Tabur di Desa Tapak Kecamatan Panekan Kabupaten Magetan

2019 ◽  
Vol 3 (2) ◽  
pp. 70-73
Author(s):  
Wuye Ria Andayanie
Keyword(s):  
Soil Erosion ◽  
Community Service ◽  
Chemical Fertilizers ◽  
Group Approach ◽  
Sloping Lands ◽  
Flower Plant ◽  
Sloping Land ◽  
Farmer Groups ◽  
High Level ◽  
Rural Appraisal

Rose (Rosa hybrida L.) is classified as the genus Rosa and is an ornamental flower plant in the form of herbs with thorny stems. Roses have many types, one of which is a type of sowing roses that are widely grown in Tapak Village, Panekan Subdistrict. Sowing roses can be used as a support for daily economic needs by residents in Tapak Village. In addition, rose plants can be used as conservation plants, if planted on a bench terrace on sloping land. The Panekan area is an area declared by the Magetan Regency Government as an area prone to landslides. Until now the terraces of sloping land in Tapak Village are often not utilized with terrace reinforcing plants, so land degradation is increasing and expanding, mainly due to the high level of soil erosion, especially in sloping areas. Utilization of conservation techniques with rose plants on sloping lands prone to erosion can reduce degradation of soil fertility. Therefore it is necessary to provide assistance for: 1) planting a terrace with rose plants; 2) supply of rose seeds and non-dependence on synthetic chemical fertilizers. Community service activities are held from October to December 2018. Each partner farmer is given training and is facilitated to supply sowing roses and compost plus for nurseries. The method of activity uses a group approach, field meeting, farmer course. The mentoring activity was carried out with a pattern of rural appraisal Participatory, namely working with members of farmer groups in Tapak Village. The results of the mentoring activities were carried out to increase the income of sowing rose farmers and reduce degradation on sloping land. Keywords—: sowing roses, terrace, degradation, Tapak Village 

Soil organic carbon losses by water erosion in a Mediterranean watershed

Soil Research ◽  
2017 ◽  
Vol 55 (4) ◽  
pp. 363 ◽  
Author(s):  
Ahmet Cilek
Keyword(s):  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
River Basin ◽  
Land Degradation ◽  
Agricultural Land ◽  
Water Erosion ◽  
Assessment Model ◽  
Ecosystem Functions ◽  
The Mediterranean

Soil organic carbon (SOC) is one of the primary elements required in the functioning of ecosystems. Soil erosion, a major mechanism of land degradation, removes SOC and transfers it to the hydrosphere or the atmosphere, thereby affecting key ecosystem functions and services. The Mediterranean region is highly susceptible to land degradation because of erosion due to heavy rains following long, dry, hot summers. Although the Mediterranean landscape typically has a high altitude and incline, the soil is brittle and soft and is easily washed away by rain. Thus, vast regions in Turkey have been afflicted by this type of soil degradation. This study aimed to (1) estimate the temporal distribution of water erosion in the Seyhan River Basin, (2) assess the spatial distribution of SOC and (3) estimate the depletion of SOC through soil erosion using the Pan-European Soil Erosion Risk Assessment model, a physically based, regionally scaled soil erosion model. The annual amount of soil eroded from the Seyhan River Basin is estimated to be 7.8million tonnes per hectare (tha–1year–1). The amount of fertile soil loss from agricultural areas is ~1.2million tonnes per year. The maximum amount of soil erosion occurs in maintenance scrubland and degraded forest areas, contributing to 68% of erosion, followed by that in agricultural land, contributing to 27% of erosion, with the remaining in forests and urban areas.

scholarly journals Lateral transport of SOC induced by water erosion in a Spanish agroecosystem

2020 ◽  
Author(s):  
Leticia Gaspar ◽  
Lionel Mabit ◽  
Ivan Lizaga ◽  
Ana Navas
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Water Erosion ◽  
Land Uses ◽  
Lateral Movement ◽  
Erosion Processes ◽  
Depositional Processes

&lt;p&gt;The main route for the lateral movement of soil organic carbon (SOC) is water erosion. Awareness of the distribution and magnitude of land carbon mobilization is important both for improving models of the carbon cycle and for management practices aimed to preserve carbon stocks and enhance carbon sinks. There is a need to consider the global significance of soil erosion from soil organic carbon cycling schemes and for this reason, the movement of SOC during erosion processes should be elucidated.&lt;/p&gt;&lt;p&gt;Our study aims to estimate the SOC redistribution induced by water erosion during a 40 years period in an agroforestry mountain ecosystem located in northern Spain. To this purpose, topographically driven transects were selected with mixed land uses to i) assess what factors modify the runoff patterns with impact on soil and carbon redistribution and ii) evaluate the mobilization of topsoil organic carbon along the transects.&lt;/p&gt;&lt;p&gt;The lateral movement of SOC shows similar spatial patterns with that of soil erosion. To identify whether erosional or depositional processes have been predominant in the sampling sites we used &lt;sup&gt;137&lt;/sup&gt;Cs inventories and the characterization of terrain attributes of the study with a detailed analysis of the main runoff pathways. Results indicate that SOC losses were related to an increase in water flow accumulation, while the highest SOC gains were recorded at concave positions. Soil erosion processes and the content of SOC in soils are the two main factors controlling carbon budgets. The topographical and geomorphological characteristics of the transects, the spatial distribution of land uses and the presence of landscape linear elements such as terraces or paths, affect runoff and determine the sediment connectivity and carbon dynamics along the slopes.&lt;/p&gt;&lt;p&gt;The interactions between topography and land use produce significant positive or negative effects on SOC accumulation, particularly in areas with complex topography, as the results obtained in our study sustain. Even though the effect of topography and land use/land cover and their interactions on the horizontal distributions of carbon remains largely unknown, our approach contributes to better understand the pattern of gains and losses of soil organic and inorganic carbon induced by water erosion.&lt;/p&gt;

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