scholarly journals Assessment of crusting effects on interrill erosion by laser scanning

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8487
Author(s):  
Yaxian Hu ◽  
Wolfgang Fister ◽  
Yao He ◽  
Nikolaus J. Kuhn

Background Crust formation affects soil erosion by raindrop impacted flow through changing particle size and cohesion between particles on the soil surface, as well as surface microtopography. Therefore, changes in soil microtopography can, in theory, be employed as a proxy to reflect the complex and dynamic interactions between crust formation and erosion caused by raindrop-impacted flow. However, it is unclear whether minor variations of soil microtopography can actually be detected with tools mapping the crust surface, often leaving the interpretation of interrill runoff and erosion dynamics qualitative or even speculative. Methods In this study, we used a laser scanner to measure the changes of the microtopography of two soils placed under simulated rainfall in experimental flumes and crusting at different rates. The two soils were of the same texture, but under different land management, and thus organic matter content and aggregate stability. To limit the amount of scanning and data analysis in this exploratory study, two transects and four subplots on each experimental flume were scanned with a laser in one-millimeter interval before and after rainfall simulations. Results While both soils experienced a flattening, they displayed different temporal patterns of crust development and associated erosional responses. The laser scanning data also allowed to distinguish the different rates of developments of surface features for replicates with extreme erosional responses. The use of the laser data improved the understanding of crusting effects on soil erosional responses, illustrating that even limited laser scanning provides essential information for quantitatively exploring interrill erosion processes.

Soil Research ◽  
2018 ◽  
Vol 56 (7) ◽  
pp. 712 ◽  
Author(s):  
Bao-jun Zhang ◽  
Guang-hui Zhang ◽  
Han-yue Yang ◽  
Hao Wang ◽  
Ning-ning Li

Vegetation restoration influences near soil-surface characteristics and thus likely affects soil erodibility. This study was performed to quantify the effects of vegetation restoration on soil erodibility on steep gully slopes, and to identify the potential influencing factors on the Loess Plateau. Three shrub and four grass types distributed on different gully slopes were selected, and six erodibility indicators and an integrated erodibility index (IEI) were applied to indirectly evaluate the effects of vegetation restoration on soil erodibility. The former included the soil erodibility K factor, aggregate stability (the mean weight diameter, MWD, and the mean number of drop impacts, MND), saturated hydraulic conductivity (Ks), cohesion (Coh), and penetration resistance (PR), and the latter was calculated using these indicators and a weighted integration method. The results showed that vegetation restoration on steep gully slopes was effective in reducing soil erodibility on the Loess Plateau, and grasses seemed more effective than shrubs. Compared with the control, the K of vegetation-restored gully slopes decreased by 4.1–24.0%, and MWD, MND, Ks, Coh, and PR increased by 64.0–284.3, 51.4–269.5, 100.5–417.4, 10.1–172.2, and 63.3–278.9% respectively. Consequently, the IEI of the vegetation-restored gully slopes declined by 33.1–81.9%, and the mean reduction percentage of the four grasses was 1.5 times that of the three shrubs. The variation in soil erodibility was closely related to the changes in the soil organic matter content and root mass density with vegetation restoration. The results will help in understanding the soil conservation mechanisms of vegetation restoration on steep gully slopes.


2021 ◽  
Vol 11 (15) ◽  
pp. 6982
Author(s):  
Chiara Ferronato ◽  
Gilmo Vianello ◽  
Mauro De Feudis ◽  
Livia Vittori Antisari

The study of Technosols development, spatial distribution and physicochemical characteristics is becoming more and more important in the Anthropocene Era. The aim of the present study was to assess soil features and potential heavy metal release risk of soils developed on different mine tailing types after the waste disposal derived from mining activity in Central Italy. Soils were analyzed for their morphological, physical and chemical properties, and a chemical sequential extraction of heavy metals was performed. The investigated soils were classified as Technosols toxic having in some layer within 50 cm of the soil surface inorganic materials with high concentrations of toxic elements. Our findings showed that the bioavailability of potentially toxic element concentrations in the soil changed according to the origin of the mine tailing. However, because of the acidic pH, there is a serious risk of metals leaching which was reduced where the soil organic matter content was higher.


2021 ◽  
Vol 51 ◽  
Author(s):  
Pedro Luan Ferreira da Silva ◽  
Flávio Pereira de Oliveira ◽  
Adriana Ferreira Martins ◽  
Danillo Dutra Tavares ◽  
André Julio do Amaral

ABSTRACT Integrated farming systems are promising strategies for the recovery of pastures and degraded soils. This study aimed to evaluate the effect of integrated farming systems arrangements, after four years of implementation, on the fertility, carbon stock and aggregate stability of an Alfisol, in the semiarid region of the Paraíba state, Brazil. A randomized block experimental design was used, with 5 treatments and 4 replications: Brachiaria decumbens; B. decumbens + Tabebuia impetiginous; B. decumbens + Gliricidia sepium; B. decumbens + Mimosa caesalpiniifolia; and B. decumbens + maize. The soil chemical attributes, fertility, carbon stock and structural and aggregate stability were evaluated in the 0.00-0.10, 0.10-0.20 and 0.20-0.30 m layers. The B. decumbens + maize system presented an organic matter content 11.93 % higher than B. decumbens, and was higher than the other systems evaluated. Concerning the carbon stock in the 0.00-0.10 m layer, in B. decumbens the uptake was 2.66 Mg ha-1 higher than that of the B. decumbens + maize system and, on average, 4.69 Mg ha-1 higher than for the systems with the arboreal component. In the medium-term, B. decumbens is more efficient in adding carbon to the soil. The soil structural stability, aggregate stability index and fertility were not affected by the different arrangements after four years of implementation.


2005 ◽  
Vol 62 (6) ◽  
pp. 572-577 ◽  
Author(s):  
Nelson Moura Brasil do Amaral Sobrinho ◽  
Nelson Mazur

Minimum tillage reportedly reduce erosion, avoid soil degradation and improve crop productivity. This study aimed to determine how tillage operations may affect either nutrient accumulation or nutrient losses by erosion. The study was, carried out from December, 2000 to March, 2001, in the watershed of the Caetés River, in Rio de Janeiro State, Brazil (22º25'43"S, 43º25'07"W). The experiment was set up in sandy clay Kandiudult soil, 60% slope, under cucumber (Cucumis sativus L.) crop. Soil samples were collected before planting and after harvest, on 22.0 X 4.0 m Greeoff plots. After each rainfall, fine sediments carried by runoff were deposited into two collecting tanks in a row, installed at the end of each plot, and were later dried, weighed and stored for analyses. Treatments (n = 4) were characterized by different tillage systems: (i) downhill plowing followed by the burning of crop residues (DPB); (ii) downhill plowing with no burning of the crop residues (DPNB); (iii) animal traction contour plowing, with strips of guinea grass planted at a spacing of 7.0 m (AT); and (iv) minimum tillage (MT). Samples of the soil-plowed layer were collected before planting and after harvest, between the rows and from the plants. Total concentration of Ca, Mg, K and P were determined after extraction with nitric perchloride digestion. Labile P and exchangeable K were extracted with the Mehlich 1 extractant solution. The MT system reduced losses of both exchangeable bases (15%) and P (8%), and affected the distribution of labile and organic P. Crop residues left on soil surface in the MT system, resulted in increased organic matter content. Downhill plowing, the most used tillage operation in the region, resulted in the greatest losses of Ca, Mg, K, and P.


2015 ◽  
Vol 7 (1) ◽  
pp. 1007-1024
Author(s):  
B. Turgut

Abstract. The aim of this study was to compare the soils of the wheat cultivation area (WCA) and the safflower cultivation area (SCA) within semi-arid climate zones in terms of their total carbon, nitrogen, sulphur contents, particle size distribution, aggregate stability, organic matter content, and pH values. This study presents the results from the analyses of 140 soil samples taken at two soil layers (0–10 and 10–20 cm) in the cultivation areas. At the end of the study, it has been established that there were significant differences between the cultivation areas in terms of soil physical properties such as total carbon (TC), total nitrogen (TN), total sulphur (TS) contents and pH, while only the TN content resulted in significantly different between the two soil layers. Moreover significant differences were identified in the cultivation areas in terms of soil physical properties including clay and sand contents, aggregate stability and organic matter content, whereas the only significant difference found among the soil layers was that of their silt content. Since safflower contains higher amounts of biomass than wheat, we found higher amounts of organic matter content and, therefore, higher amounts of TN and TS content in the soils of the SCA. In addition, due to the fact that wheat contains more cellulose – which takes longer to decompose – the TC content of the soil in the WCA were found to be higher than that of the SCA. The results also revealed that the WCA had a higher carbon storage capacity.


Weed Science ◽  
1985 ◽  
Vol 33 (6) ◽  
pp. 861-867 ◽  
Author(s):  
C. John Peter ◽  
Jerome B. Weber

Significantly higher rates of butralin [4-(1,1-dimethylethyl)-N-(1-methylpropyl)-2,6-dinitrobenzenamine] were required to produce the same level of weed control as trifluralin [2,6-dinitro -N,N-dipropyl-4-(trifluoromethyl) benzenamine] when applied to soybeans [Glycine max(L.) Merr.] on seven different soils in the field. Higher rates of butralin were also required to control barnyardgrass [Echinochloa crus-galli(L.) Beauv. ♯ ECHCG] in growth chamber studies. No differences in the extent of soil adsorption of trifluralin and butralin were apparent; therefore, differences in efficacy could not be attributed to differences in soil adsorption. Herbicide rates required for 80% weed control and Freundlich K-values (adsorption capacity indices) were mostly highly correlated with soil organic-matter content and soil surface area as measured by benzyl ethyl ether (BEE) and ethylene glycol monoethyl ether (EGME) on nine soils. Analysis of the organic-matter content of the nine soils by 10 soil testing laboratories resulted in highly significant differences among laboratories.


2017 ◽  
Vol 30 (2) ◽  
pp. 343-352 ◽  
Author(s):  
JOSÉ DE SOUZA OLIVEIRA FILHO ◽  
MARCOS GERVASIO PEREIRA ◽  
BOANERGES FREIRE DE AQUINO ◽  
THALES VINÍCIUS DE ARAÚJO VIANA

ABSTRACT The objective of this study was to evaluate the adsorption of phosphorus (P) and changes in the concentrations of organic and inorganic forms of P in a Neossolo Quartzarênico (Typic Quartzipsamment) after 9 years of successive cultivation with sugar cane without burning to harvest. Therefore, two areas, one in which cane sugar was planted and a native forest reference area, located in the municipality of Paraipaba-CE, were selected. In each area, samples were collected at depths of 0−0.025, 0.025−0.05, 0.05−0.10, 0.10−0.20, and 0.20−0.30 m, and the levels of organic (Po) and inorganic (Pi) phosphorus obtained by sequential extraction, the remaining phosphorus, and the maximum adsorption capacity of phosphorus by the soil were determined. In general, the permanence of straw on the soil surface under sugarcane cultivation promoted the maintenance of Po levels in the surface layers of the profile. The Po accumulated predominantly in the Po fraction extracted with sodium bicarbonate in both areas. Regarding the Pi content, changes were more evident during cultivation due to the effect of successive phosphate fertilizer applications. The fraction extracted with 0.1 mol L -1 sodium hydroxide was the most representative, with the highest levels of P uptake. P adsorption was influenced by the initial content of the nutrient in the soil and no relationship between P adsorption and organic matter content was observed. The highest level of adsorption was observed in the bottom layer of the forest area (133.3 mg kg -1) and the lowest level of adsorption was observed on the surface layer of the area under sugarcane cultivation (59.5 kg mg-1).


1993 ◽  
Vol 8 (1) ◽  
pp. 27-33 ◽  
Author(s):  
J.L. Jordahl ◽  
D.L. Karlen

AbstractQuantitative studies are needed to separate the real and supposed benefits of alternative farming practices. Our objective was to learn how conventional and alternative practices on adjacent farms in central Iowa affected the water stability of soil aggregates. We collected samples of Clarion loam (fine-loamy, mixed, mesic Typic Hapludoll) from adjacent 16 ha fields in fall 1990 and spring 1991. Aggregate stability was determined by wet-sieving and by measuring turbidity of soil-water suspensions. The combined effects of alternative practices resulted in greater water stability of soil aggregates, higher soil organic matter content, and lower bulk density compared with conventional practices. The components of the alternative system that were mainly responsible for these differences were: rotations that included oat and hay crops; ridge-tillage; and additions of 45 Mg/ha of a mixture of animal manure and municipal sludge during the first 3 years of each 5 year rotation. The more favorable soil physical conditions, shown by increased water stability of soil aggregates, presumably will improve soil water regimes and reduce long-term soil erosion losses from the alternatively managed fields.


Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Radka Kodešová ◽  
Marcela Rohošková ◽  
Anna Žigová

AbstractSoil structure stability was studied in every diagnostic horizons of six soil types (Haplic Chernozem, Greyic Phaeozem, two Haplic Luvisols, Haplic Cambisol, Dystric Cambisol) using different techniques investigating various destruction mechanisms of soil aggregates. Soil aggregate stability, assessed by the index of water stable aggregates (WSA), varied depending on the organic matter content, clay content and pHKCl. The presence of clay and organic matter coatings and fillings, and presence of iron oxides in some soils increased stability of soil aggregates. On the other hand periodical tillage apparently decreased aggregate stability in the Ap horizons. Coefficients of aggregate vulnerability resulting from fast wetting (KV 1) and slow wetting (KV 2) tests showed similar trends of the soil aggregate stability as the WSA index, when studied for soils developed on the similar parent material. There was found close correlation between the WSA index and the KV 1 value, which depended also on the organic matter content, clay content and pHKCl. Less significant correlation was obtained between the WSA index and the KV 2 value, which depended on the organic matter content and clay content. Coefficients of vulnerability resulting from the shaking after pre-wetting test (KV 3) showed considerably different trends in comparison to the other tests due to the different factors affecting aggregate stability against the mechanical destruction. The KV 3 value depended mostly on cation exchange capacity, pHKCl and organic matter content.


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