scholarly journals Estimating the Effect of Rain Splash on Soil Particle Transport by Using a Modified Model: Study on Short Hillslopes in Northern China

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2318
Author(s):  
Yanjun Wang ◽  
Fan Yang ◽  
Shenglin Qi ◽  
Jinhua Cheng
Keyword(s):  
Field Experiments ◽  
Soil Surface ◽  
Northern China ◽  
Surface Flow ◽  
Interactive Effects ◽  
Rainfall Simulation ◽  
Vegetation Coverage ◽  
Splash Erosion ◽  
Overland Runoff ◽  
Rain Splash

Splash erosion is an important soil erosion process in sloping lands. This study aims to improve the model of rain splash transport based on the results of previous studies and field experiments involving rainfall simulation. A field study was conducted to examine the effects of rainfall properties, herbaceous cover and surface flow on splash processes on hillslopes in northern China. On the basis of the experimental results, a comprehensive model of rain splash was established through the quantitative analysis of the interactive effects of rainfall kinetic energy, vegetation coverage and overland runoff depth on splash erosion rate and the probability density of splashed particles and maximum splash distance. The results showed that the estimated and observed values of splash transport exhibit high consistency and adaptability. However, several discrepancies were observed between the estimated and observed values for events with high vegetation coverage. These differences can be ascribed to the variation in overland runoff connectivity and the differences in soil surface cohesion at various wetness degrees. The proposed model provides insights into splash erosion characteristics and suggestions for erosion control practices on hillslopes.

Development and Testing of an Unmanned Aerial Vehicle for Large Scale Particle Image Velocimetry

2014 ◽  
Author(s):  
Christopher Pagano ◽  
Flavia Tauro ◽  
Salvatore Grimaldi ◽  
Maurizio Porfiri
Keyword(s):  
Particle Image Velocimetry ◽  
Large Scale ◽  
Field Experiments ◽  
Particle Image ◽  
Low Cost ◽  
Surface Flow ◽  
Natural Environments ◽  
Natural Stream ◽  
Image Velocimetry ◽  
Scale Particle

Large scale particle image velocimetry (LSPIV) is a nonintrusive environmental monitoring methodology that allows for continuous characterization of surface flows in natural catchments. Despite its promise, the implementation of LSPIV in natural environments is limited to areas accessible to human operators. In this work, we propose a novel experimental configuration that allows for unsupervised LSPIV over large water bodies. Specifically, we design, develop, and characterize a lightweight, low cost, and stable quadricopter hosting a digital acquisition system. An active gimbal maintains the camera lens orthogonal to the water surface, thus preventing severe image distortions. Field experiments are performed to characterize the vehicle and assess the feasibility of the approach. We demonstrate that the quadricopter can hover above an area of 1×1m2 for 4–5 minutes with a payload of 500g. Further, LSPIV measurements on a natural stream confirm that the methodology can be reliably used for surface flow studies.

scholarly journals A field perspective on effects of fire and temperature fluctuation on Cerrado legume seeds

2017 ◽  
Vol 27 (2) ◽  
pp. 74-83 ◽  
Author(s):  
L. Felipe Daibes ◽  
Talita Zupo ◽  
Fernando A.O. Silveira ◽  
Alessandra Fidelis
Keyword(s):  
Temperature Fluctuation ◽  
Field Experiments ◽  
Seed Viability ◽  
Soil Surface ◽  
Temperature Fluctuations ◽  
Fire Effects ◽  
Fuel Load ◽  
Physical Dormancy ◽  
Legume Seeds ◽  
Field Perspective

AbstractInformation from a field perspective on temperature thresholds related to physical dormancy (PY) alleviation and seed resistance to high temperatures of fire is crucial to disentangle fire- and non-fire-related germination cues. We investigated seed germination and survival of four leguminous species from a frequently burned open Neotropical savanna in Central Brazil. Three field experiments were conducted according to seed location in/on the soil: (1) fire effects on exposed seeds; (2) fire effects on buried seeds; and (3) effects of temperature fluctuations on exposed seeds in gaps and shaded microsites in vegetation. After field treatments, seeds were tested for germination in the laboratory, together with the control (non-treated seeds). Fire effects on exposed seeds decreased viability in all species. However, germination of buried Mimosa leiocephala seeds was enhanced by fire in an increased fuel load treatment, in which we doubled the amount of above-ground biomass. Germination of two species (M. leiocephala and Harpalyce brasiliana) was enhanced with temperature fluctuation in gaps, but this condition also decreased seed viability. Our main conclusions are: (1) most seeds died when exposed directly to fire; (2) PY could be alleviated during hotter fires when seeds were buried in the soil; and (3) daily temperature fluctuations in gaps also broke PY of seeds on the soil surface, so many seeds could be recruited or die before being incorporated into the soil seed banks. Thus seed dormancy-break and germination of legumes from Cerrado open savannas seem to be driven by both fire and temperature fluctuations.

Evaluating the Efficiency of Crushed Gravel Filters around Field Drains

2021 ◽  
Author(s):  
Amer Al-Haddad ◽  
◽  
Dhuha Mahdi ◽  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Surface ◽  
Filter Material ◽  
Head Loss ◽  
Surface Flow ◽  
Laboratory Work ◽  
Drain Pipe ◽  
Drainage Systems ◽  
Total Head ◽  
Irrigation Condition

Engineers have employed various ways to protect drain openings from the entry of sediment with varying degrees of success. This study aims to compare and evaluate the hydraulic performance and efficiency of using natural graded gravel filter and crushed gravel filter in drainage systems. An aquifer tank (sand tank) 70 cm long, 50 cm wide and 80 cm high, a perforated drain pipe of 50 mm diameter was used in the laboratory work. The laboratory study was performed with two types of soil: loam and loamy sand. These two soils were used with the two types of gravel filters after taking the particle size distribution test for the two soils. For each case, the inflow was applied to the model from the soil surface (to represent irrigation condition) and from the sides of the tank (to represent sub –surface flow condition and effluence of the groundwater). Each case involved ten runs; for each run, discharge, total head loss, and amount of sediment were recorded. It was found that crushed gravel filter would work similarly to natural graded gravel filter after a certain time from the beginning of runs. It was also found that the discharge and sediment when using crushed gravel filter were close to or equal to that with natural graded gravel filter. The hydraulic conductivity and the exit gradient values were calculated in this research. It was found that their values were so different between the two types of filters, but at the end of the laboratory work, the hydraulic conductivity would be approximately the same. The exit gradient of crushed gravel filter was lower than that of natural graded gravel filter due to the large pores between the filter particles. Finally, the results showed that, it is possible to use crushed gravel filter material in drainage systems, which is less costly and easier to place than natural graded gravel filter.

Technologies of drop irrigation of young almond garden on terraces in foothland conditions of the Kyzylsu-Yuzhnaya river basin

2021 ◽  
Vol 0 (1) ◽  
pp. 12-15
Author(s):  
Daler Domullodzhanov
Keyword(s):  
River Basin ◽  
Drip Irrigation ◽  
Field Experiments ◽  
Soil Surface ◽  
Perennial Grasses ◽  
Minimum Amount ◽  
Almond Orchard

The article presents the results of field experiments on the study of the technology of drip irrigation of a young almond orchard on terraces with clear cover with tillage soil surface, with use of mulching and overseeding of perennial grasses. In the variant with mulching, the minimum amount of irrigation observed – 24, with the irrigation norm – 1904 litre per tree. In other cases, the number of irrigation events increases from 8 to 23, respectively, the irrigation norms are 1.39 and 2.06 times.

scholarly journals An Improved Method to Estimate Soil Hydrodynamic and Hydraulic Roughness Parameters by Using Easily Measurable Data During Flood Irrigation Experiments and Inverse Modelling

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1581
Author(s):  
Mohamed Alkassem Alosman ◽  
Stéphane Ruy ◽  
Samuel Buis ◽  
Patrice Lecharpentier ◽  
Jean Bader ◽  
...  
Keyword(s):  
Soil Surface ◽  
Surface Flow ◽  
Performance Criteria ◽  
Soil Parameters ◽  
Well Performance ◽  
Estimation Errors ◽  
Hydraulic Roughness ◽  
Infiltration Model ◽  
Estimation Uncertainty ◽  
Using Data

Surface irrigation is known as a highly water-consuming system and needs to be optimized to save water. Models can be used for this purpose but require soil parameters at the field scale. This paper aims to estimate effective soil parameters by combining: (i) a surface flow-infiltration model, namely CALHY; (ii) an automatic fitting algorithm based on the SIMPLEX method; and (iii) easily accessible and measurable data, some of which had never been used in such a process, thus minimizing parameter estimation errors. The validation of the proposed approach was performed through three successive steps: (1) examine the physical meaning of the fitted parameters; (2) verify the accuracy of the proposed approach using data that had not been served in the fitting process; and (3) validate using data obtained from independent irrigation events. Three parameters were estimated with a low uncertainty: the saturated hydraulic conductivity Ks, the hydraulic roughness k, and the soil water depletion ∆θ. The estimation uncertainty of the soil surface depressional storage parameter H0 was of the same order of magnitude of its value. All experimental datasets were simulated very well. Performance criteria were similar during both the fitting and validation stages.

scholarly journals Crop residues on short-term CO2 emissions in sugarcane production areas

2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior
Keyword(s):  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Dry Mass ◽  
Agricultural Crop ◽  
Short Term ◽  
Sugarcane Production ◽  
Soil Temperatures ◽  
Production Areas

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.

Do applications of sulfur or sulfate influence infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae) in canola?

2002 ◽  
Vol 82 (3) ◽  
pp. 599-610 ◽  
Author(s):  
L. M. Dosdall ◽  
R. -C. Yang ◽  
P. M. Conway
Keyword(s):  
Brassica Rapa ◽  
Field Experiments ◽  
Elemental Sulfur ◽  
Insect Pest ◽  
Soil Surface ◽  
Application Rate ◽  
Delia Radicum ◽  
Application Methods ◽  
Root Maggot ◽  
Sulfur Nutrition

While the importance of sulfur nutrition for the development of healthy stands of canola is well documented, the role of sulfur in the management of insect pest infestations has not previously been investigated in this crop. Field experiments were conducted at three sites in central Alberta in 1997 and 1998 to determine the influence of sulfur and sulfate applications on infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae) in canola (Brassica rapa L.). Different formulations (granules, powder, prills, and sprays), application methods (either drilled in with the seed or top-dressed on the soil surface), and application rates were evaluated. To assess the degree of root maggot infestation, oviposition throughout the season and damage to taproots at the end of the season were monitored. Sulfur contents were analyzed from leaf samples collected mid-season and seed yields were measured from all treatment plots. Root maggot responses to the different sulfur treatments and application methods varied among years and sites, indicating that environmental factors have great importance in determining infestation levels by these pests, and the oxidation rate of elemental sulfur in soil. Sulfur formulation and application rate had significant effects on root maggot egg deposition and root damage for some sites and years, but even at high rates of application (112 kg ha-1) reductions in infestation levels were not substantial relative to the controls. While sulfur additions alone will not greatly reduce root maggot infestation levels in canola, growers should employ adequate sulfur nutrition for optimum crop health to enable plants to better compensate for damage by these pests. Key words: Brassica rapa, Delia radicum, Delia floralis, elemental sulfur, sulfate, canola

scholarly journals The Influence of Moss Colonization and Biochar Application on Evaporation Losses and Surface Crack in Shallow Carbonate–Derived Laterite During Dry–Wet Cycles

2021 ◽  
Author(s):  
Lulu Che ◽  
Dongdong Liu ◽  
Dongli She
Keyword(s):  
Soil Moisture ◽  
Soil Surface ◽  
Soil Evaporation ◽  
Interactive Effects ◽  
Surface Cracks ◽  
Evaporation Model ◽  
Soil Desiccation ◽  
Evaporation Losses ◽  
Soil Moisture Conservation ◽  
Surface Temperature Field

Abstract AimsSoil water deficit in karst mountain lands is becoming an issue of concern owing to porous, fissured, and soluble nature of underlying karst bedrock. It is important to identify feasible methods to facilitate soil water preservation in karst mountainous lands. This study aims to seek the possibility of combined utilization of moss colonization and biochar application to reduce evaporation losses in carbonate-derived laterite.MethodsThe treatments of the experiments at micro-lysimeter included four moss spore amounts (0, 30, 60, and 90 g·m−2) and four biochar application levels (0, 100, 400, and 700 g·m−3). The dynamics of moss coverage, characteristics of soil surface cracks and surface temperature field were identified. An empirical evaporation model considering the interactive effects of moss colonization and biochar application was proposed and assessed.ResultsMoss colonization reduced significantly the ratio of soil desiccation cracks. Relative cumulative evaporation decreased linearly with increasing moss coverage under four biochar application levels. Biochar application reduced critical moss coverage associated with inhibition of evaporation by 33.26%-44.34%. The empirical evaporation model enabled the calculation of soil evaporation losses under moss colonization and biochar application, with the R2 values ranging from 0.94 to 0.99.Conclusions Our result showed that the artificially cultivated moss, which was induced by moss spores and biochar, decreased soil evaporation by reducing soil surface cracks, increasing soil moisture and soil surface temperature.Moss colonization and biochar application has the potential to facilitate soil moisture conservation in karst mountain lands.

INFLUENCE OF CASSAVA (MANIHOT ESCULENTA) INTERCROP ON GROWTH AND FRUIT YIELDS OF PEPPER (CAPSICUM SPP.) IN SOUTH-WESTERN NIGERIA

2007 ◽  
Vol 43 (1) ◽  
pp. 79-95 ◽  
Author(s):  
F. O. OLASANTAN ◽  
A. W. SALAU ◽  
E. E. ONUH
Keyword(s):  
Manihot Esculenta ◽  
Field Experiments ◽  
Radiant Energy ◽  
Soil Surface ◽  
Fruit Yield ◽  
Earthworm Casts ◽  
Area Index ◽  
Growth Environment ◽  
Premium Price ◽  
Capsicum Spp

In tropical Africa, pepper (Capsicum spp.) is grown as a rainfed crop, and its production is limited by the long, hot growing season. Field experiments were conducted in Nigeria to evaluate the effects of cassava (Manihot esculenta) on the growth and yields of three pepper cultivars and gross returns in 2001–2003. In Experiment 1, pepper (cv. Sombo) was planted between rows of cassava cvs Idileru (PI), Odongbo (PO) and TMS 30572 (PT). In Experiment 2, pepper cvs Sombo, Tatase and Atarodo, were mixed with TMS 30572 (MS, MT or MA). The growth environment for the intercropped pepper differed from sole crops of pepper. Radiant energy reaching the soil surface, maximum diurnal soil and canopy temperatures, and weed growth were lower with intercropping, with the lowest values being observed in the PI and PT intercrops. Similarly, soil moisture content and the number of earthworm casts were greater with intercropping, with the highest values also occurring in the PI and PT intercrops. In both experiments, fresh fruit yields of pepper depended on the duration of harvest, the number of fruits per plant and the weight of fruits. In Experiment 1, although the number of fruits and fruit yield of cv. Sombo were greater in the sole crop (SP) than the PO intercrop, the fruit yields in the PI and PT intercrops were similar to those of the SP plot. In Experiment 2, the number of fruits and yield of intercropped pepper cvs Tatase, Sombo and Atarodo were 25–28 % higher, on average, than in pure stands. Cassava tuber yield was not affected by intercropped pepper in either experiment. Total gross returns were greater than growing either pepper or cassava in monoculture. Increased total gross returns in the intercrops were obtained in the PI and PT treatments and in the MS and MA treatments without a significant reduction in pepper fruit yield. By promoting early fruit set and harvest, and bearing in mind the cumulative gross returns, mixing pepper and cassava enhanced the value of the vegetable, as early fresh pepper fruits command a premium price. It is concluded that pepper can be grown between cassava rows to provide a suitable environment for growth, but that this depends on the cassava cultivar. Using the less tall early cassava cultivar, with a relatively moderate leaf area index in a mixture with pepper is therefore recommended.

Dissipation and Water Activation of UCC-C4243

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 149-155 ◽  
Author(s):  
Terry R. Wright ◽  
Alex G. Ogg ◽  
E. Patrick Fuerst
Keyword(s):  
Field Experiments ◽  
Soil Surface ◽  
Simulated Rainfall ◽  
Herbicide Application ◽  
Weed Species ◽  
Natural Rainfall ◽  
Near Ultraviolet ◽  
Glass Slides ◽  
Water Activation ◽  
Herbicide Activity

Field experiments were conducted in 1992 and 1993 to determine the timing and amount of rainfall required to activate UCC-C4243 applied preemergence. UCC-C4243 at 0, 70, and 140 g ai ha−1was applied 1, 7, 14, and 21 d before 0.5 or 2 cm of simulated rainfall. Temporary rainshelters protected field plots from natural rainfall during the 21 d dry period. Herbicide activity was determined in the field by seeding lentil, wheat, common lambsquarters, and field pennycress and in the greenhouse by a sugarbeet bioassay of soil samples (0 to 3 cm depth) taken from all plots immediately before irrigation. UCC-C4243 did not injure wheat; however, lentil population was reduced when simulated rainfall occurred within 7 d after application. Lentil injury was greater with higher herbicide rate and higher water level. UCC-C4243 at 70 and 140 g ha−1reduced populations of both weed species by 75 and 90%, respectively, when either 0.5 or 2 cm simulated rainfall was received within 1 d after herbicide application. Weed control was reduced with a 21 d delay between herbicide application and water activation. The sugarbeet bioassay showed a linear decrease of herbicide activity over time and also with accumulated photosynthetically active radiation. After 17.9 d, herbicide activity on a dry soil surface decreased 50%. Laboratory investigations show that [14C]-UCC-C4243 on glass slides was photodegraded by near ultraviolet light (290 to 400 nm). Volatilization of14C-labeled herbicide from glass slides was less than 5% after exposure to turbulent air for 48 h.

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