The role of soil surface water regimes and raindrop impact on hillslope soil erosion and nutrient losses

Raindrop driven erosion &#8211; what is in the black box ?P.I.A. KinnellFaculty of Science and Technology, University of Canberra, Canberra, AustraliaMany experiments applying rainfall to produce erosion on soil surfaces consider the inputs and outputs in a black box situation where little or no consideration is given to the actual mechanisms controlling erosion. It is well known that rainfall erosion is caused by raindrop impact and flow forces acting singly or together. Raindrops impacting directly or through surface water detaches soil material from where it is held within the soil surface by cohesion and inter-particle friction&#160; and erosion occurs if the detached material is transported away from the site of detachment. The movement of detached material downslope may be in the air by splash or more importantly in surface water flows where raindrop impact may induce coarse sediment may to move when sediment transport normally associated with undisturbed flow does not occur. These transport processes vary in space and time during laboratory and field experiments. How this influences the amounts of soil loss during these experiments is the subject of&#160; this presentation .

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Soil crusting in relation to global soil degradation

American Journal of Alternative Agriculture ◽

10.1017/s088918930000446x ◽

1992 ◽

Vol 7 (1-2) ◽

pp. 56-62 ◽

Cited By ~ 10

Author(s):

Malcolm E. Sumner ◽

William P. Miller

Keyword(s):

Soil Erosion ◽

Soil Degradation ◽

Seedling Emergence ◽

Soil Surface ◽

Clay Dispersion ◽

Soil Crusting ◽

The World ◽

Global Soil ◽

Raindrop Impact

The formation of crusts or seals at the soil surface is exceedingly important in determining how much rainfall infiltrates into the soil and how much runs off, causing soil erosion. This paper explores the processes involved in the formation of crusts, such as raindrop impact and clay dispersion, to formulate a picture of the mechanisms involved. We discuss the major consequences of crusting, namely, runoff, erosion, and impaired seedling emergence, and present strategies to reduce soil degradation. Examples are offered from many parts of the world.

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The role of the geometry and frequency of rectangular rills in the relationship between sediment concentration and stream power

Soil Research ◽

10.1071/s97019 ◽

1997 ◽

Vol 35 (6) ◽

pp. 1359 ◽

Cited By ~ 2

Author(s):

B. Fentie ◽

C. W. Rose ◽

K. J. Coughlan ◽

C. A. A. Ciesiolka

Keyword(s):

Soil Erosion ◽

Overland Flow ◽

Sediment Concentration ◽

Stream Power ◽

Flume Experiments ◽

Erosion Processes ◽

Physically Based ◽

The Relationship ◽

Raindrop Impact

We examined, both experimentally and theoretically, whether rilling results in higher soil erosion than would have occurred without rilling. The possibility of rilling occurs when overland flow-driven erosion processes are dominant over erosion due to raindrop impact, and that is the situation assumed in this paper. Stream power (or a quantity related to stream power such as shear stress) is commonly used to describe the driving variable in flow-driven erosion. Five flume experiments were designed to investigate the relationship between stream power and sediment concentration and how this relationship is affected by the ratio of width to depth of flow (r), and the frequency or number of rills per metre width (N) of rectangular rills. This paper presents the results of these experiments and uses a physically based soil erosion theory to show that the results of the 5 flume experiments are in accord with this theory. This theory is used to investigate the effect of all possible rectangular rill geometries and frequencies on the maximum possible sediment concentration, i.e. the sediment concentration at the transport limit, by developing general relationships for the influence of r and N on sediment concentration. It is shown that increased stream power, which can be due to rilling, does not necessarily result in higher sediment concentration.

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Shear stress caused by artificial raindrop impact at the soil surface

10.35688/2413-8452-2017-04-005 ◽

2017 ◽

Vol 4 ◽

pp. 27-36

Author(s):

Olgarenko G.V. ◽

Bryl S.V. ◽

Zverkov M.S.

Keyword(s):

Shear Stress ◽

Laboratory Testing ◽

Strain State ◽

Soil Surface ◽

Shear Stresses ◽

Significance Level ◽

Rain Erosion ◽

Raindrop Impact

The purpose of this research is to develop methods of determination of the stress-strain state of the soil due to the drop impact of the artificial rain to increase the accuracy and simplify the research of drop and rain erosion, field and laboratory testing of sprinkler equipment. The calculation of the shear stresses arising at the point of impact drops of art ificial rain on soil, the role of these stresses in the mechanism for the development of drop and rain erosion, the expediency this value for testing irrigation equipment. For impacts of drop with a diameter of 1.73 mm on the basis of the magnitude of the shear stress was 158.44 ± 7.32 kPa (significance level p < 0.001) to 281.76 ± 11.18 kPa (p < 0.001) in the fall drops with a height from 1.0 до 2.5 m, respectively. For the case of hitting the ground drops with a diameter of 2.73 mm shear stress was 196.51 ± 5.72 kPa (p < 0.001) to 339.71 ± 33.35 kPa (p < 0.001) in the fall drops with a height from 1.0 to 2.5 m, respectively. The values of shear stress τ significantly correlated with the values of the drop height h (for drops with a diameter dd = 1.73 mm correlation coefficient r = 0.963 ± 0.029, p < 0.001; for dd = 2.73 mm r = 0.977 ± 0.014, p < 0.001). The median time of impact of drop 1.73 mm by soil was (5.95 ± 0.57) ∙ 10–5 sec., for the drop with a diameter 2.73 mm the time was (6.53 ± 0.67) ∙ 10–5 sec. Weber numbers We for the drop with the diameter of 1.73 mm were 459...1156, for the drop with the diameter of 2.73 mm – 728...1829.

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Managing Landscape Irrigation to Avoid Soil and Nutrient Losses

EDIS ◽

10.32473/edis-ss586-2013 ◽

2013 ◽

Vol 2013 (11) ◽

Author(s):

George Hochmuth ◽

Laurie Trenholm ◽

Don Rainey ◽

Esen Momol ◽

Claire Lewis ◽

...

Keyword(s):

Natural Environment ◽

Management Practices ◽

Root Zone ◽

Irrigation Management ◽

Critical Factor ◽

Nutrient Losses ◽

County Agents ◽

The Right ◽

Soil And Water

Proper irrigation management is critical to conserve and protect water resources and to properly manage nutrients in the home landscape. How lawns and landscapes are irrigated directly impacts the natural environment, so landscape maintenance professionals and homeowners must adopt environmentally-friendly approaches to irrigation management. After selecting the right plant for the right place, water is the next critical factor to establish and maintain a healthy lawn and landscape. Fertilization is another important component of lawn and landscape maintenance, and irrigation must be applied correctly, especially following fertilization, to minimize potential nutrient losses. This publication supplements other UF/IFAS Extension publications that also include information on the role of soil and the root zone in irrigation management. This publication is designed to help UF/IFAS Extension county agents prepare materials to directly address nutrient losses from lawns and landscapes caused by inadequate irrigation management practices. This 6-page fact sheet was written by George Hochmuth, Laurie Trenholm, Don Rainey, Esen Momol, Claire Lewis, and Brian Niemann, and published by the UF Department of Soil and Water Science, October 2013. http://edis.ifas.ufl.edu/ss586

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Effect of Digestate and Straw Combined Application on Maintaining Rice Production and Paddy Environment

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18115714 ◽

2021 ◽

Vol 18 (11) ◽

pp. 5714

Author(s):

Xue Hu ◽

Hongyi Liu ◽

Chengyu Xu ◽

Xiaomin Huang ◽

Min Jiang ◽

...

Keyword(s):

Organic Matter ◽

Surface Water ◽

Soil Organic Matter ◽

Paddy Soil ◽

Rice Yield ◽

Soil Surface ◽

Rice Production ◽

Straw Decomposition ◽

Rice Grains ◽

Combined Application

Few studies have focused on the combined application of digestate and straw and its feasibility in rice production. Therefore, we conducted a two-year field experiment, including six treatments: without nutrients and straw (Control), digestate (D), digestate + fertilizer (DF), digestate + straw (DS), digestate + fertilizer + straw (DFS) and conventional fertilizer + straw (CS), to clarify the responses of rice growth and paddy soil nutrients to different straw and fertilizer combinations. Our results showed that digestate and straw combined application (i.e., treatment DFS) increased rice yield by 2.71 t ha−1 compared with the Control, and digestate combined with straw addition could distribute more nitrogen (N) to rice grains. Our results also showed that the straw decomposition rate at 0 cm depth under DS was 5% to 102% higher than that under CS. Activities of catalase, urease, sucrase and phosphatase at maturity under DS were all higher than that under both Control and CS. In addition, soil organic matter (SOM) and total nitrogen (TN) under DS and DFS were 20~26% and 11~12% higher than that under B and DF respectively, suggesting straw addition could benefit paddy soil quality. Moreover, coupling straw and digestate would contribute to decrease the N content in soil surface water. Overall, our results demonstrated that digestate and straw combined application could maintain rice production and have potential positive paddy environmental effects.

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Impact of Weed Control by Hand Tools on Soil Erosion under a No-Tillage System Cultivation

Agronomy ◽

10.3390/agronomy11050974 ◽

2021 ◽

Vol 11 (5) ◽

pp. 974

Author(s):

Rafael Blanco-Sepúlveda ◽

Amilcar Aguilar-Carrillo ◽

Francisco Lima

Keyword(s):

Soil Erosion ◽

Weed Control ◽

Soil Cover ◽

Soil Surface ◽

Conservation Agriculture ◽

Soil Disturbance ◽

No Tillage ◽

Tropical Mountains ◽

Litter Cover ◽

Vegetal Cover

In conservation agriculture, the no-tillage cultivation system and the retention of permanent vegetal cover are crucial to the control of soil erosion by water. This paper analyses the cultivation of maize under no-tillage, with particular reference to the effect produced on soil erosion when weed control is performed by a hand tool (machete), which disturbs the surface of the soil, and to the behavior of the soil cover in these circumstances. The study area is located in the humid tropical mountains of northern Nicaragua (Peñas Blancas Massif Nature Reserve). The results obtained show that 59.2% of the soil surface was affected by appreciable levels of sheet and splash erosion, although the vegetal cover of the soil was relatively high (with average weed and litter cover of 33.9% and 33.8%, respectively). The use of machetes for weed control provoked considerable soil disturbance, which explained the high rates of erosion observed. Moreover, this form of soil management disturbs the litter layer, making it less effective in preventing erosion. The litter remains loose on the soil surface, and so an increase in soil cover does not achieve a proportionate reduction in the area affected by erosion; thus, even with 80–100% weed and litter cover, 42% of the cultivated area continued to present soil erosion.

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