scholarly journals Losses of soil, water, organic carbon and nutrients caused by water erosion in different crops and natural savannah in the northern Amazon

2018 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Fernando Gomes de Souza ◽  
Valdinar Ferreira Melo ◽  
Wellington Farias Araújo ◽  
Thiago Henrique de Castro Araújo
Keyword(s):  
Organic Carbon ◽  
Soil Water ◽  
Plant Cover ◽  
Soil Surface ◽  
Bare Soil ◽  
Water Erosion ◽  
Brachiaria Brizantha ◽  
Water Losses ◽  
Agricultural Areas ◽  
The Impact

Currently in Brazil, the main form of erosion is caused by the impact of raindrops on the soil surface, triggering the process of water erosion and causing serious damage to agricultural areas. This study evaluated losses of soil, water, organic carbon and nutrients in different cultures, bare soil and savanna under natural rain. The experimental design was completely randomized with five treatments (bare soil - BS, cowpea bean - CB, Brachiaria brizantha - BB, corn - CO and natural savanna – SN) with three replications; The treatment of bare soil (BS), followed by the treatment cultivated with cowpea bean  (CB) showed higher losses of soil, water, organic carbon and nutrients; The highest losses of soil, water, organic carbon and nutrients in the treatment of bare soil (BS) occurred during the period of greatest erosivity; but for treatments CB, BB and CO, the highest losses occurred during the establishment of the crop, in view of the lower soil cover. Soils cultivated with Brachiaria brizantha - BB, corn - CO and in the Natural Savana - SN area were more efficient in reducing soil and water losses during all months evaluated. Plant cover produced by the (SN) treatment and by the (BB) and (CO) treatments acted to reduce the harmful effects of erosion, minimizing losses of nutrients and organic carbon. The soil should be well protected during periods when rainfall presents the highest values of erosivity index.

Testing sudden shifts in drylands through manipulative mesocosm experiments

2020 ◽  
Author(s):  
Susana Bautista ◽  
Francisco Fornieles ◽  
David Fuentes ◽  
Anna M Urgeghe ◽  
Diana Turrión ◽  
...  
Keyword(s):  
Experimental Approach ◽  
Experimental Testing ◽  
Surface Condition ◽  
Plant Cover ◽  
Soil Surface ◽  
Bare Soil ◽  
Mesocosm Experiments ◽  
Small Change ◽  
The Impact ◽  
Lower Capacity

<p>A variety of theoretical and observational works indicate that drylands may experience sudden shifts from functional to degraded states in response to gradual increases in human and climatic pressures. However, there is little experimental testing of the factors and processes that control sudden shifts in drylands. Adopting a combination of mesocosms and manipulative experimental approach, we assessed the occurrence of sudden transitions towards degraded states in response to increasing pressure, and investigated the mechanisms underlying the observed dynamics. We mimicked a gradually increasing pressure of grazing and wood gathering by removing increasing amounts of vegetation on a series of experimental plots and mesocosms. We then monitored the impact of such gradient of pressure on runoff and sediment yield, vegetation dynamics, bare-soil connectivity and soil-surface condition over a 7-year period.  Overall, our results support that decreasing plant cover nonlinearly increases the loss of resources from the system and may trigger a change to a degraded state. Within the range from 40% to 30 % vegetation cover, a small change in the cover percentage resulted in a turning point in both the vegetation and the hydrological dynamics, driving the system to a new state that exhibited lower capacity for resource conservation all over the study period.</p>

scholarly journals Water erosion associated with rainfall patterns in the extreme South of Bahia in eucalyptus post-planting

2017 ◽  
Vol 38 (4Supl1) ◽  
pp. 2463
Author(s):  
Danielle Vieira Guimaraes ◽  
Marx Leandro Naves Silva ◽  
Diêgo Faustolo Alves Bispo ◽  
Sérgio Gualberto Martins ◽  
Jose De Oliveira Melo Neto ◽  
...  
Keyword(s):  
Plant Cover ◽  
Bare Soil ◽  
Water Erosion ◽  
Rainfall Pattern ◽  
Environmental Damage ◽  
Soil Productivity ◽  
Native Forest ◽  
Water Losses ◽  
Rainfall Patterns ◽  
Soil And Water

Soil and water losses caused by water erosion represent a risk of environmental damage and loss of soil productivity, with economic, social and environmental consequences. Plant cover is an important ally against water erosion, together with the knowledge of rainfall characteristics. Thus, this study aimed to evaluate the soil and water losses and to determine rainfall patterns in two homogeneous eucalyptus plantations; one in Yellow Argisol, located in Teixeira de Freitas, and another in Humiluvic Spodosol, located in Caravelas, both in the Extreme South of the state of Bahia. Erosion plots were installed, and consisted of three treatments: bare soil, eucalyptus, and native forest. Rainfall data was obtained from an automatic gauging station, with 10 minute registration interval for erosivity (erosivity index EI30) and rainfall pattern analyses. Higher soil losses were observed in Yellow Argisol, and the advanced rainfall pattern was predominant. Eucalyptus minimum tillage was efficient in reducing soil and water losses by water erosion.

scholarly journals Water erosion associated with rainfall patterns in the extreme South of Bahia in eucalyptus post-planting

2017 ◽  
Vol 38 (4Supl1) ◽  
pp. 2463
Author(s):  
Danielle Vieira Guimaraes ◽  
Marx Leandro Naves Silva ◽  
Diêgo Faustolo Alves Bispo ◽  
Sérgio Gualberto Martins ◽  
Jose De Oliveira Melo Neto ◽  
...  
Keyword(s):  
Plant Cover ◽  
Bare Soil ◽  
Water Erosion ◽  
Rainfall Pattern ◽  
Environmental Damage ◽  
Soil Productivity ◽  
Native Forest ◽  
Water Losses ◽  
Rainfall Patterns ◽  
Soil And Water

Soil and water losses caused by water erosion represent a risk of environmental damage and loss of soil productivity, with economic, social and environmental consequences. Plant cover is an important ally against water erosion, together with the knowledge of rainfall characteristics. Thus, this study aimed to evaluate the soil and water losses and to determine rainfall patterns in two homogeneous eucalyptus plantations; one in Yellow Argisol, located in Teixeira de Freitas, and another in Humiluvic Spodosol, located in Caravelas, both in the Extreme South of the state of Bahia. Erosion plots were installed, and consisted of three treatments: bare soil, eucalyptus, and native forest. Rainfall data was obtained from an automatic gauging station, with 10 minute registration interval for erosivity (erosivity index EI30) and rainfall pattern analyses. Higher soil losses were observed in Yellow Argisol, and the advanced rainfall pattern was predominant. Eucalyptus minimum tillage was efficient in reducing soil and water losses by water erosion.

Soil temperature and the energy balance of vegetative mulch in the semi-arid tropics. II. Dynamic analysis of the total energy balance

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 515 ◽  
Author(s):  
PJ Ross ◽  
J Williams ◽  
RL Mccown
Keyword(s):  
Energy Balance ◽  
Soil Water ◽  
Water Loss ◽  
Crop Production ◽  
Soil Surface ◽  
Bare Soil ◽  
Lower Atmosphere ◽  
Water Losses ◽  
Total Energy Balance ◽  
Soil Temperatures

Soil temperatures and water losses under killed vegetative mulch canopies are examined in the context of no-tillage crop production, using a numerical dynamic model of the soil, canopy and lower atmosphere. Both liquid and vapour movement in the soil are included, as are free and forced convection in the canopy. The predictions of the model for a clay loam soil are as follows. Medium and heavy mulches reduce the water loss over six days by 1.4 and 2.7 mm respectively, the reduction occurring while the soil surface is wet. This small effect is important in giving seedlings an extra 2 or 3 days for establishment. Water loss from bare soil and under a medium mulch is limited by soil resistance even on the first day of evaporation from initially wet soil. Mulch canopies that intercept 80 and 50% of incoming radiation can keep surface soil temperatures within 10 and 20�C respectively of ambient, whereas bare soil temperatures may rise 30�C above ambient. A moderate wind reduces soil temperatures under a mulch only a few degrees, but cools the canopy much more. A rough soil surface helps cool the soil. Water losses and soil temperatures are little affected by a 50% change in soil water diffusivity or thermal conductivity. An extensive mulched area results in temperatures well above those observed on small plots surrounded by transpiring vegetation, which maintains cool air above the mulch. A simplified form of the model, which incorporates only a single mulch layer and which ignores effects of wind, yields soil temperatures which are not greatly different from those generated by the more complex model for wind speeds below 1 ms-1 at canopy height.

scholarly journals Soil water erosion under different cultivation systems and different fertilization rates and forms over 10 years

2014 ◽  
Vol 38 (6) ◽  
pp. 1918-1928 ◽  
Author(s):  
Ildegardis Bertol ◽  
Fabrício Tondello Barbosa ◽  
Álvaro Luiz Mafra ◽  
Murilo Córdova Flores
Keyword(s):  
Soil Water ◽  
Mineral Fertilizer ◽  
Soil Surface ◽  
Fertilizer Application ◽  
Water Erosion ◽  
No Tillage ◽  
Common Vetch ◽  
Water Losses ◽  
Natural Rainfall ◽  
Soil Losses

The action of rain and surface runoff together are the active agents of water erosion, and further influences are the soil type, terrain, soil cover, soil management, and conservation practices. Soil water erosion is low in the no-tillage management system, being influenced by the amount and form of lime and fertilizer application to the soil, among other factors. The aim was to evaluate the effect of the form of liming, the quantity and management of fertilizer application on the soil and water losses by erosion under natural rainfall. The study was carried out between 2003 and 2013 on a Humic Dystrupept soil, with the following treatments: T1 - cultivation with liming and corrective fertilizer incorporated into the soil in the first year, and with 100 % annual maintenance fertilization of P and K; T2 - surface liming and corrective fertilization distributed over five years, and with 75 % annual maintenance fertilization of P and K; T3 - surface liming and corrective fertilization distributed over three years, and with 50 % annual maintenance fertilization of P and K; T4 - surface liming and corrective fertilization distributed over two years, and with 25 % annual maintenance fertilization of P and K; T5 - fallow soil, without liming or fertilization. In the rotation the crops black oat (Avena strigosa ), soybean (Glycine max ), common vetch (Vicia sativa ), maize (Zea mays ), fodder radish (Raphanus sativus ), and black beans (Phaseolus vulgaris ). The split application of lime and mineral fertilizer to the soil surface in a no-tillage system over three and five years, results in better control of soil losses than when split in two years. The increase in the amount of fertilizer applied to the soil surface under no-tillage cultivation increases phytomass production and reduces soil loss by water erosion. Water losses in treatments under no-tillage cultivation were low in all crop cycles, with a similar behavior as soil losses.

Straw mulch impact on soil properties and initial soil erosion processes in the maize field

2021 ◽  
Author(s):  
Ivan Dugan ◽  
Leon Josip Telak ◽  
Iva Hrelja ◽  
Ivica Kisić ◽  
Igor Bogunović
Keyword(s):  
Soil Erosion ◽  
Soil Water ◽  
Soil Loss ◽  
Bare Soil ◽  
Water Erosion ◽  
Straw Mulch ◽  
Erosion Processes ◽  
Maize Field ◽  
Sediment Loss ◽  
Initial Soil

<p><strong>Straw mulch impact on soil properties and initial soil erosion processes in the maize field</strong></p><p>Ivan Dugan*, Leon Josip Telak, Iva Hrelja, Ivica Kisic, Igor Bogunovic</p><p>University of Zagreb, Faculty of Agriculture, Department of General Agronomy, Zagreb, Croatia</p><p>(*correspondence to Ivan Dugan: [email protected])</p><p>Soil erosion by water is the most important cause of land degradation. Previous studies reveal high soil loss in conventionally managed croplands, with recorded soil losses high as 30 t ha<sup>-1</sup> under wide row cover crop like maize (Kisic et al., 2017; Bogunovic et al., 2018). Therefore, it is necessary to test environmentally-friendly soil conservation practices to mitigate soil erosion. This research aims to define the impacts of mulch and bare soil on soil water erosion in the maize (Zea mays L.) field in Blagorodovac, Croatia (45°33’N; 17°01’E; 132 m a.s.l.). For this research, two treatments on conventionally tilled silty clay loam Stagnosols were established, one was straw mulch (2 t ha<sup>-1</sup>), while other was bare soil. For purpose of research, ten rainfall simulations and ten sampling points were conducted per each treatment. Simulations were carried out with a rainfall simulator, simulating a rainfall at an intensity of 58 mm h<sup>-1</sup>, for 30 min, over 0.785 m<sup>2</sup> plots, to determine runoff and sediment loss. Soil core samples and undisturbed samples were taken in the close vicinity of each plot. The results showed that straw mulch mitigated water runoff (by 192%), sediment loss (by 288%), and sediment concentration (by 560%) in addition to bare treatment. The bare treatment showed a 55% lower infiltration rate. Ponding time was higher (p < 0.05) on mulched plots (102 sec), compared to bare (35 sec), despite the fact that bulk density, water-stable aggregates, water holding capacity, and mean weight diameter did not show any difference (p > 0.05) between treatments. The study results indicate that straw mulch mitigates soil water erosion, because it immediately reduces runoff, and enhances infiltration. On the other side, soil water erosion on bare soil under simulated rainstorms could be high as 5.07 t ha<sup>-1</sup>, when extrapolated, reached as high as 5.07 t ha<sup>-1 </sup>in this study. The conventional tillage, without residue cover, was proven as unsustainable agro-technical practice in the study area.</p><p><strong>Key words: straw mulch, </strong>rainfall simulation, soil water erosion</p><p><strong>Acknowledgment</strong></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><p><strong>Literature</strong></p><p>Bogunovic, I., Pereira, P., Kisic, I., Sajko, K., Sraka, M. (2018). Tillage management impacts on soil compaction, erosion and crop yield in Stagnosols (Croatia). Catena, 160, 376-384.</p><p>Kisic, I., Bogunovic, I., Birkás, M., Jurisic, A., Spalevic, V. (2017). The role of tillage and crops on a soil loss of an arable Stagnic Luvisol. Archives of Agronomy and Soil Science, 63(3), 403-413.</p>

Sediment content and chemical properties of water runoff on biocrusts in drylands

Biologia ◽  
2014 ◽  
Vol 69 (11) ◽  
Author(s):  
Roberto Lázaro ◽  
Juan Mora
Keyword(s):  
Dry Matter ◽  
Chemical Properties ◽  
Soil Surface ◽  
Water Erosion ◽  
Rainfall Simulation ◽  
Water Runoff ◽  
Protective Capacity ◽  
Runoff Water ◽  
Wide Range ◽  
The Impact

AbstractIn drylands, water erosion can be a process with important economic and ecological implications, and is very dependent on the soil surface cover. There is broad agreement that biocrusts protect the soil from erosion in a wide range of circumstances. However, there is little information available on the effect of rain and biocrust types on this protective capacity and there is particularly very little knowledge on the erosive effects of runoff on biocrusts, which are expected to be larger in larger drainage areas, on the resistance of biocrusts to the combined effect of raindrops plus runoff flow and on the solute mobilisation by runoff in biocrusts. To answer these questions, we performed 96 rainfall-simulation in situ factorial experiments, including two biocrust types (cyanobacteria and lichens), three rain types (42, 63 and 77 mm h−1, always 20 min rain), four plot lengths (1, 2, 3 and 4 m long) and four replicates. In each experiment, runoff volume was measured and a runoff sample was taken to determine (i) the amount of dry matter in runoff, (ii) the amount of organic matter among the dry matter, (iii) the electrical conductivity, pH and alkalinity in runoff water. The main findings were: biocrusts strongly protected soil against water erosion, even under the most erosive conditions, and the protection increased with the successional development. Biocrusts were very resistant to the impact of raindrops and also to runoff flow, although an emergent hypothesis arose: under the most erosive conditions, a threshold of erodibility could be reached at the cyanobacterial biocrust. The lichen crust also protected the soil against the removal of soil soluble substances. The development of a biocrust could change the chemical composition of the solutes in runoff.

Impact droplets and the protection of soils by plant covers

Soil Research ◽  
1989 ◽  
Vol 27 (1) ◽  
pp. 1 ◽  
Author(s):  
AJ Moss
Keyword(s):  
Edge Effects ◽  
Soil Surface ◽  
Water Erosion ◽  
Drop Diameter ◽  
Double Edge ◽  
Conversion Rates ◽  
The Impact ◽  
Drop Water ◽  
Overall Effectiveness

Impact droplets, the fine drops splashed from the impact sites of larger drops on plant elements, were investigated experimentally to assess their role in water erosion. It was found that impact droplets rarely strike the soil surface before decelerating markedly from their sometimes high initial velocities. This, and their small sizes, render them almost non-erosive. Their production therefore represents a major soil-conserving mechanism in that large, potentially erosive drops are converted to almost harmless drizzle. Conversion rates of incident-drop water to impact droplets were found to be about 10-25% by weight for large, effectively semi-infinite targets, but rose rapidly to about 90% as impact points approached within half a drop diameter of target edges. Most impacts on plant elements are edge-affected and elements of about the same diameter as a raindrop (e.g. those of fine grasses) produce double-edge effects, almost entirely converting incident drops into impact droplets. These results, combined with previous findings, allow consideration of the abilities of different arrays of plant elements (i.e. 'covers') to combat water erosion generally. Closely spaced, near-ground, plant elements, about 1-3 mm in diameter, display a peculiar overall effectiveness in this respect.

scholarly journals Numerical simulation of bare soil water and heat flow under an automated irrigation system

2015 ◽  
Vol 50 (4) ◽  
pp. 336-348
Author(s):  
Mohamed H. Ahmed ◽  
Saud Gutub
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Depth ◽  
Irrigation System ◽  
Meteorological Data ◽  
Soil Surface ◽  
Bare Soil ◽  
Time Lags ◽  
Irrigation Systems ◽  
Automated Irrigation System

Modern irrigation techniques use automated systems where irrigation schedules are controlled according to certain criteria. The objective of this study is to numerically estimate irrigation events, water content and temperature distributions, evaporation, drainage, and soil water under closed loop automated irrigation systems of a bare soil. The automated irrigation system is activated and deactivated according to the water content value. The governing equations for transient one-dimensional liquid water flow and heat transfer of unsaturated porous media are applied. The energy balance equation at the soil surface is used as an upper boundary condition based on measured meteorological data of Jeddah City. The results show that the current procedure can be applied to simulate different variables under automated irrigation systems. The water content shows periodic behavior, as well as time lags and decreases in amplitude with soil depth. The timing of applied irrigation has an important impact on evaporation and soil temperature. Applying irrigation water during the daytime leads to increased evaporation. The soil surface temperature decreases suddenly when water is supplied in the afternoon, while a slight increase is observed when irrigation is applied at midnight.

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