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12.
Hamza Mohieddinne Boris Brasseur Emilie Gallet-Moron Jonathan Lenoir Fabien Spicher Ahmad Kobaissi Hélène Horen 《Land Degradation u0026amp; Development》2023,34(5):1558-1569
To ensure sustainable forest management, the assessment and monitoring of soil compaction and rutting are essential. Here, we used airborne light detection and ranging-derived digital terrain model (LiDAR-derived DTM), available for the forest of Compiègne in northern France, to compute a spatial index of soil rutting. Following an environmental systematic sampling design, we selected 45 plots representative of the forest stand conditions where we subsequently extracted information from the DTM to compute the cumulative length of ruts (CLR). To assess the quality of this LiDAR-derived index, we related the CLR index to in-situ soil and vegetation parameters such as soil texture, soil pH, and understory plant species composition. Floristic surveys were carried out across all 45 plots to generate plant species response curves along the CLR gradient. We found soil texture, soil type, and soil pH to be important determinants of CLR. For instance, CLR was the highest in soils with the highest clay content. A total of 22 out of the 94 understory plant species we analyzed showed a significant response curve along the CLR gradient. Most important, the occurrence probability of species associated with wet soils and stagnant waters (e.g., Juncus effusus), like those found in ruts, increased with CLR. Other species associated with dry soils (e.g., Hedera helix) showed a negative response curve along the CLR gradient. In conclusion, the proposed index (CLR) has proven useful to remotely assess soil compaction and rutting after logging operations. 相似文献
13.
《Land Degradation u0026amp; Development》2017,28(2):708-717
Man‐made and natural sediment sinks provide a practical means for reducing downstream reservoir sedimentation by decreasing soil erosion and enhancing the rate of sedimentation within a catchment. The Minizr catchment (20 km2) in the northwest Ethiopian highlands contains numerous man‐made soil and water conservation (SWC) structures such as soil bunds (Erken), fanya juu ridge (Cab) and micro‐trenches and natural sediment sinks such as wetlands, floodplains and grassed waterways. These sediment sinks reduce downstream sedimentation into the Koga reservoir, located at the catchment outlet, however, a large quantity of sediment is still reaching the reservoir. This study evaluates the function and effectiveness of both man‐made SWC structures and natural sediment sinks in reducing sediment export from the Minizr catchment. SWC structures and natural sediment sinks were digitized using Google Earth Imagery. Sediment pins and vertical sampling through the deposit were used to quantify the amount of deposited sediment. In addition, inflow and outflow of suspended sediment data were used to calculate the sediment‐trapping efficacies (STE) of man‐made SWC structures (soil bunds and fanya juu ridges) and natural sediment sinks. Results reveal that 144 km soil bunds and fanya juu ridges trapped 7,920 Mg y−1 (55 kg m−1 y−1) and micro‐trenches trapped 13·26 Mg y−1, each micro‐trench on average trapped 23 kg y−1. The 17 ha floodplain located in the centre of the catchment trapped 9,970 Mg y−1 (59 kg m−2 y−1), while a wetland with a surface area of 24 ha, located near the outlet of the catchment, trapped 8,715 Mg y−1 (36 kg m−2 y−1). The STEs of soil bunds and fanya juu ridges, wetlands and floodplains were 54%, 85% and 77%, respectively. Substantial differences were observed between the STE of grassed and un‐grassed waterways at 75% and 21%, respectively. Existing man‐made and natural sediment sinks played an important role in trapping sediment, with 38% (26,600 Mg y−1) of transported sediment being trapped, while 62% (43,000 Mg y−1) is exported from the catchment and thus enters the Koga reservoir. Therefore, additional catchment treatment measures are required as an integrated catchment scale sediment trapping approach to help reduce sediment loads entering Koga reservoir. Moreover, to maximize the effectiveness of sediment trapping measures, avoid structural failure and ensure their sustainability, regular maintenance is needed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
14.
石灰性土壤上利用天然沸石活化磷矿粉的初步探讨 总被引：9，自引：0，他引：9
在石灰性土壤上以磷矿粉和天然沸石为试材进行盆栽试验,结果表明,在石灰性土壤上沸石对磷矿粉具有较强的活化作用,能使土壤速磷增加１４．１％－５０．５％,植物磷素增加５．０％－２１．７％,大豆产量增加９．８％－２０．７％,另外,沸石的施用量也并非越多越好,在本试验中,沸石以每盆施１２．５ｇ的效果最好。 相似文献
15.
《Communications in Soil Science and Plant Analysis》2012,43(3):187-195
Abstract A field experiment was conducted to determine whether Zn applied for pathogen control could accumulate to a level which would be toxic to snapbeans, cucumbers, or corn. Zinc sulfate (ZnSO4) was applied at rates varying from 0 to 363 kg Zn/ha on a Flainfield loamy sand to approximate 3, 9, 27 and 81 years of fungicidal treatment. Even at the high rate of Zn, yields of snapbeans, cucumbers, or corn generally were not reduced. As rates of applied Zn increased, there was a corresponding increase in the level of Zn in the leaf tissue of all crops grown. At the high Zn rate, snapbean and cucumber leaf tissue accumulated over 350 ppm Zn. Available soil Zn was extracted with 0.1N HCl, EDTA, or DTPA. Highly significant correlations were observed between the Zn removed by each extractant and plant tissue Zn, thus, indicating that the various extractants were equally effective in predicting Zn uptake. Very little downward movement of Zn was observed. Two and one‐half years after application, the Zn had leached to a depth of only 30 cm in the soil profile at the higher Zn rates. These data indicate that application of Zn‐containing fungicides and bactericides should not cause a Zn toxicity problem on the Plainfield sand in the foreseeable future. 相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(19-20):2635-2646
Abstract Assessing base cation [calcium (Ca2+), magnesium (Mg2+), potassium (K+)] fluxes is necessary for determining ecosystem stability. This study was conducted in the Osinovka River catchment located on the Khamar‐Daban Ridge, South Baikal, which is characterized by high precipitation (more than 1700 mm per annum). The contributions of different ecosystem components such as atmospheric deposition, soil exchange pool, minerals, vegetation, surface water, and groundwater into the total base cations flux were evaluated, combining the strontium isotope approach and budget study. Results show the leading role of atmosphere in ecosystem supply with base cations. The atmosphere contributes 48% of total base cations flux, and its contributions to plant‐available nutrition pools of both organic and mineral horizons are equal to 50%. This makes the vitality of vegetation, to a great extent, dependent on the stability of atmospheric chemistry. 相似文献
17.
Dietmar Horn 《植物养料与土壤学杂志》2006,169(1):83-86
With the electro–ultrafiltration (EUF) technique, the plant availability of several plant nutrients in soils can be characterized. The basic principle of EUF is that an electric field is induced using platinum electrodes. Ions in the soil suspension move either to the cathode or to the anode and are filtrated through ultra‐membrane filters. In the standard EUF procedure, two extractions steps are used: 30 min at 20°C and 5 min at 80°C. However, the determination of micronutrients and heavy metals with the standard EUF procedure is not possible, because the solubility of these elements in water is low and most of the watersoluble elements are precipitated when passing the platinum electrodes. The addition of DTPA, a well known complexing agent, during a third EUF fraction (5 min at 80°C) enables extraction of micronutrients and heavy metals. Highest concentrations in the 33 soils of the study were found for iron, followed by zinc, manganese, lead, copper, and nickel. Lower concentrations were obtained for cobalt, chromium, cadmium, and molybdenum. For two soils, the EUF/DTPA procedure was compared to CaCl2/DTPA and EDTA soil extraction methods, showing that higher or comparable amounts were found with CaCl2/DTPA and much higher amounts with the EDTA method. These results reveal that the EUF/DTPA technique in principle can be used for the determination of plant‐available micronutrients and heavy metals. However, in a next step the relationship between EUF/DTPA‐extractable elements and their availability for plants needs to be quantified. 相似文献
18.
H. Aïchi Y. Fouad D. Causeur C. Walter 《Communications in Soil Science and Plant Analysis》2020,51(9):1253-1267
ABSTRACT Many factors could influence simultaneously soil spectra. We aimed to study the single effect of organic carbon and total iron in soil visible and short-wave near-infrared spectra and to quantify their contents. Two datasets of soil mixture samples were prepared by mixing, in various fractions, an organic carbon-rich material with a total iron-rich material and then with a total iron-poor material. For these two datasets, contents in organic carbon are quite similar but contents in total iron are significantly different. Results show that samples of the same dataset have the same overall spectral shape. Organic carbon has a decreasing effect that affects the whole spectral range without showing any specific absorption peaks. By contrast, total iron has specific absorption peaks. Spectra of the second dataset characterized by soil mixtures with higher total iron contents were more compact within the spectral bands 400–440 and 920–950 nm. Besides, continuum removal enables to exaggerate absorption peaks of wavelengths linked to total iron content. Partial Least Squares Regression (PLS R) models of both total organic carbon and total iron assign high coefficients to the wavelengths that are considered relevant and conversely low coefficients to those that are considered irrelevant. Both organic carbon content and total iron content were well predicted. For these models, coefficients of determination were superior to 0.9 and RMSE was closed to zero. The global models calibrated on all the samples demonstrated that PLS R was able to integrate sample heterogeneity. 相似文献
19.
Abstract Phenolic compounds occurring naturally are reducing agents which react with hydrous Fe oxide and Mn oxides (Lehmann et al. 1987). Diphenols such as hydroquinone, resorcinol, and catechol were oxidatively darkened by the presence of hydrous Fe oxide though the degree of darkening was much less pronounced than that by Mn oxides (Shindo and Huang 1984). Okazaki et al. (1976) suggested that polyphenols are one of the materials responsible for the dissolution of Mn in a paddy soil under reducing conditions. 相似文献
20.