scholarly journals Degradation processes in the soils of the Kolodnytsia River basin

Author(s):  
Nadiya Lemega

This article presents the results of soil degradation studies of the Kolodnytsia River basin. The basin approach is applied in soil-geographical studies. The conditions for the formation of soils are studied depending on the morphometric characteristics of the river basin and soil-bearing rocks. The analysis of the causes of the spread of degradation processes of various species, which cause soil degradation, is carried out. Particular attention is paid to the anthropogenic factor of soil degradation, which began with the development of the territory by white Croats, that is, more than a thousand years ago. To study the degradation processes in the soils of the basin of the Kolodnytsia River, the following methods were used: comparative-geographic, comparative-profile, analytical, statistical, cartographic, basin, and catena. Field studies were conducted in the after-vegetation period. Soil erosion is the most widespread degradation process in the basin of the Kolodnytsia River, which is characterized by the destruction of the soil cover, the removal, transfer and redeposition of the soil mass. Over the past decades, erosion degradation has accelerated and taken on greater dimensions. Erosion degradation caused a decrease in the thickness of the genetic profile of soils, in weakly eroded varieties by 20 cm, in moderately eroded ones by 44 cm. In cultivated soils, the structural and aggregate state deteriorates. The content of agronomically valuable aggregates in the size of 10-0.25 mm in the humus-eluvial horizon of NOT soil under the forest is 52.6 %, under arable land – 25.3 %. The structural and aggregate composition of soils is characterized as satisfactory, the structural ratio is 1.10. Water erosion not only leads to a change in the morphological characteristics and physical properties of the soil, but also to loss of humus in the soil, nitrogen, phosphorus and other nutrients, a decrease in fertility and the like. To reduce soil degradation, it is necessary to minimize soil loading, improve the humus condition, and conserve moderately eroded soil. Key words: podzolic-soddy soils, degradation processes, water erosion, land conservation.

Author(s):  
Volodymyr Haskevych

The article presents the results of the study of Male Polissia podzolic chernozems profile degradation. The causes and consequences of this dangerous natural and man-made phenomenon resulting in changes in the habitus of soils, losses of soil mass and humus, deterioration of general physical properties and structural and aggregate composition, decrease in soil fertility and agriculture unprofitability on the slopes have been analysed. In the study of the profile degradation of podzolic chernozems, the following methods have been used: comparative-geographical, comparative-profile, soil-catena, analytical, and statistical. Field studies were conducted after the vegetation period. According to the study results, the thickness of the profile of weakly eroded podzolic chernozems, in comparison with non-eroded types, decreased by 17.0–35.5% as compared to the standard, which corresponds to satisfactory and pre-crisis condition, in medium eroded soils - by 32.2–63.4%, the degree of degradation is estimated as pre-crisis, crisis and catastrophic. In the highly eroded types, the thickness of the soil layer decreased by 47.8–74.9%, which indicates a high and very high (crisis) level of profile degradation. Erosion soil loss compared to the standard in weakly eroded podzolic chernozems is 1245.0-3744.6 t/ha, in medium eroded soil – 6762.4-8321.0 t/ha, and in highly-eroded soil – 8874.0-11595.0 t/ha. It has been established that chernozems as a result of water erosion from one hectare of weakly eroded podzolic, on average 39.47–118.70 tons of humus was eroded, 214.36-237.98 tons was eroded from medium eroded ones, and 240.49-267.84 tons from highly eroded soils. The average annual loss of humus is from 0.23-0.68 t/ha in weakly eroded types to 1.37-1.53 t/ha in highly eroded podzolic chernozems. Erosion processes result in deterioration of physical properties of soils. The use of dense and low-humus plumage horizons for plowing causes compaction of soils and deterioration of structure. Minimization of podzolic chernozem profile degradation in Male Polissia is possible provided that the system of anti-erosion measures, especially the conservation of highly eroded soils, the introduction of soil protection methods for soil cultivation, optimization of the structure of crop areas, ban on cultivated crops on slopes more than 3° steep, consolidation of small areas in larger arrays are applied. It is also necessary to introduce a system of basic and crisis monitoring over the condition of eroded soils. Key words: Male Polissia, podzolic chernozems, profile degradation, water erosion, humus, soil conservation.


Agronomy ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 257 ◽  
Author(s):  
Agata Novara ◽  
Giovanni Stallone ◽  
Artemio Cerdà ◽  
Luciano Gristina

Soil erosion has been considered a threat for semi-arid lands due to the removal of solid materials by water and wind. Although water erosion is currently considered the most important process of soil degradation, a growing interest has been drawn to the impact of soil tillage. Although numerous studies on tillage erosion have been carried out on arable land using a moldboard plow, a chisel, and a tandem disc for different crops, there are no studies on the effect of shallow tillage on soil redistribution in vineyards. The aim of this work was to evaluate the soil tillage erosion rate in a vineyard using a 13C natural abundance tracer. A strip of soil (C3-C soil) was removed, mixed with C4-C tracer, and replaced. After the installation of the strip, tillage (upslope in one inter-row and downslope in the other inter-row) was performed with a cultivator and soil was collected along the slope with an interval of 0.2 m from the C4-C strip. Soil organic carbon and δ13C were measured and the total mass of translocated soil (T) soil was calculated. The net effect of tillage after two consecutive operations (downslope and upslope tillage) was a T of 49.3 ± 4.2 kg m−1. The estimated annual erosion rate due to tillage in the studied vineyard was 9.5 ± 1.2 Mg ha−1year−1. The contribution of the soil tillage erosion rate was compared with that of water erosion in the same vineyard, and we conclude that tillage is a threat to soil degradation.


2014 ◽  
Vol 4 ◽  
Author(s):  
José Asterio Guerra-García ◽  
Carmen Dolores Arbelo ◽  
Antonio Rodríguez-Rodríguez

Soil degradation processes have achieved the recognition of a global environmental problem in recent years. It has been suggested by various international forums and organizations that in order to adequately establish methods to combat land degradation, it is necessary to evaluate this degradation locally and at a detailed scale. The evaluation of soil degradation of natural ecosystems at a detailed scale requires the definition of standards to which to compare this degradation. To define these standards and properly handle the processes that give rise to variations in soil quality and degradation, it is necessary to establish in some detail the pedogenic processes that have or have not taken place in a particular area and which lead to the formation of a mature soil. A mature soil should be considered as standard in these situations and, therefore, a non-degraded soil. This paper presents the possible evolutive and regressive sequences of soil, and provides some examples of using this methodology to evaluate the degradation of the same in the Monteverde of the island of Tenerife. It also presents some physical, chemical and mineralogical properties of climacic mature soils, degraded soils and low quality soils, and examines their similarities and differences in this bioclimatic environment and on different parent materials. Thus it is observed that the main processes of degradation in these areas are related to plant cover modifications that lead to the decreasing protection of the soil surface, which results in the long term, in the onset of degradation processes such as water erosion, biological degradation, loss of andic properties, compaction and sealing and crusting surface, loss of water retention capacity, illuviation, etc. Climacic soils that can be found in areas of steep lava flows are Leptosols, while gently sloping areas are Cambisols and Andosols. On pyroclastic materials there are vitric Andosols and andic Andosols according to their degree of evolution. The most characteristic regressive processes are illuviation/leaching, resulting in Luvisols, Lixisols and Alisols; and water erosion, causing the presence of secondary Leptosols.


2020 ◽  
Vol 12 (24) ◽  
pp. 4047
Author(s):  
Marián Jenčo ◽  
Emil Fulajtár ◽  
Hana Bobáľová ◽  
Igor Matečný ◽  
Martin Saksa ◽  
...  

The presented study uses the recent colour aerial photographs, historical black and white aerial photographs, and detailed digital elevation model to assess the spatial distribution and long-term temporal dynamics of soil loss in agriculturally intensively exploited loess hilly land with a subcontinental temperate climate. The strongly eroded soils appear in the studied area as bright patterns, surrounded by darker soils, and they are well visible on aerial photos. Three approaches of interpretation of aerial photographs were tested: visual interpretation, pixel-based image classification, and object-based image classification. All three methods provided detailed maps of soil redistribution patterns. The bright areas as the areas of soil degradation characterized by erosion increased from 1949 until 2011 by 76%. A detailed map of areal erosion patterns was used for the validation of water erosion models. LS-factor of USLE and ED’ index of USPED were selected for expressing the relation of real erosion to the terrain. The relationship between surface morphology and real erosion is very complex, and the tested water erosion models do not express it sufficiently. Therefore, the first and second-order directional derivative of the surface elevations with respect to the tillage direction has been tested. The absolute value of the first-order directional derivative showed better results and better corresponded with the real erosion pattern than the other morphometric characteristics. The findings suggest that tillage is the dominant erosion factor in the area.


1970 ◽  
Vol 23 ◽  
Author(s):  
M. Van Miegroet

A  certain number of measurable characteristics of tree leaves (morphological  characteristics, absorption of light radiation, intensity of respiration and  photosynthesis) are clearly linked with the presence of physiologically  active pigments in the leaves.     Leaf characteristics are highly and inequally influenced by changing  conditions of light environment, especially those related to light intensity,  light quality and duration of the daily illumination period. These  modifications do not only apply to light radiation as created under  laboratory conditions, but also to light conditions ensuing from the place in  the crown of a single tree, the social position of the tree in a forest stand  and the site factors in general.     There are also changes taking place due to the progression of the  vegetation period, at the end of which all species are less tolerant or more  light demanding. The reaction of the leaves towards light radiation out of  different regions of the spectrum is also different. The so-called blue light  radiation (λmax = 440 nm) seems to be of the greatest importance in this  relation, as species react quite different to its action.     The biggest variation in leaf characteristics due to changing light  environment was measured for oak and beech, which both react quickly and are  qualified as 'photolabile species'. No important variations occur in leaves  of ash and maple, which therefore are qualified as 'photostable species'.      As a consequence of variable reactions to changing light conditions, the  relationships between the species are continually modified, even in such a  way that their potential for dominance is not constant.     The classical division into tolerant and intolerant species or  classification of the species based upon the degree of light demand, is  highly inaccurate and it seems preferable to speak of relative light demands  and relative tolerance. All these observations and conclusions bring about a  clear confirmation of the necessity to recognize the individuality of the  single tree, the special character of each growth condition, the own  structure of each forest stand, the specific reaction to one sided  modifications of environmental factors. This is especially important for an  intensive sylvicultural practice.     They also prove the necessity for more physiological and biochemical  research to arrive at a better understanding of growth and its mechanism.      Sylviculture in fact must try to regulate, on an expanded scale, the  phenomens of growth, which is the exchange, absorption and transformation of  energy.     A practical interpretation and regulation of fundamental laws of physiology  and growth will be possible as soon as a clinical form of sylviculture is  created and the adequate instrumentarium developed.


2021 ◽  
Vol 13 (4) ◽  
pp. 647
Author(s):  
Fan Sun ◽  
Yi Wang ◽  
Yaning Chen ◽  
Yupeng Li ◽  
Qifei Zhang ◽  
...  

The desert-oasis ecotone, as a crucial natural barrier, maintains the stability of oasis agricultural production and protects oasis habitat security. This paper investigates the dynamic evolution of the desert-oasis ecotone in the Tarim River Basin and predicts the near-future land-use change in the desert-oasis ecotone using the cellular automata–Markov (CA-Markov) model. Results indicate that the overall area of the desert-oasis ecotone shows a shrinking trend (from 67,642 km2 in 1990 to 46,613 km2 in 2015) and the land-use change within the desert-oasis ecotone is mainly manifested by the conversion of a large amount of forest and grass area into arable land. The increasing demand for arable land for groundwater has led to a decline in the groundwater level, which is an important reason for the habitat deterioration in the desert-oasis ecotone. The rising temperature and drought have further exacerbated this trend. Assuming the current trend in development without intervention, the CA-Markov model predicts that by 2030, there will be an additional 1566 km2 of arable land and a reduction of 1151 km2 in forested area and grassland within the desert-oasis ecotone, which will inevitably further weaken the ecological barrier role of the desert-oasis ecotone and trigger a growing ecological crisis.


Author(s):  
Eva Marín ◽  
Maria Carme Sistach ◽  
Jessica Jiménez ◽  
Miguel Clemente ◽  
Guillem Garcia ◽  
...  

AbstractLong-time preservation of manuscripts depends on the stability of their support. One of the most important degradation processes of paper manuscripts containing iron gall ink is the acid hydrolysis of cellulose. The heterogeneity of the distribution of their constituent materials, together with the defined position of ink as a source of degradation agents, makes it difficult to obtain reliable and detailed information about degradation processes. The aim of this study is to contribute to the knowledge of the acid degradation process by looking at the distribution of relevant variables (pH, acidity and alkaline reserve) on real untreated iron gall ink containing manuscripts at different degradation stages. The study discusses the well-known differences between surface and cold extraction pH determination. It corroborates the relationship between pH, acidity and alkalinity and degradation stages, pointing out that acidity values for some manuscripts in apparent good condition are not far from those obtained for degraded manuscripts. The results indicate that in some partially degraded manuscripts, the coexistence of acid areas and areas with an alkaline reserve which do not participate in the neutralization process is possible. The role of water as a solvent for this equilibrium has also been evaluated.


1996 ◽  
Vol 33 (4-5) ◽  
pp. 109-115 ◽  
Author(s):  
Hans B. Wittgren ◽  
Berit Arheimer

Source apportionment of river substance transport, i.e. estimation of how much each source in each subbasin contributes to the river-mouth transport, is a vital step in achieving the most efficient management practices to reduce pollutant loads to the sea. In this study, the spatially lumped (at sub-catchment level), semi-empirical PULSE hydrological model, with a nitrogen routine coupled to it, was used to perform source apportionment of nitrogen transport in the Söderköpingsån river basin (882 km2) in south-eastern Sweden, for the period 1991–93. The river basin was divided into 28 subbasins and the following sources were considered: land leakage from the categories forest, arable and ley/pasture; point sources, and; atmospheric deposition on lake surfaces. The calibrated model yielded an explained variance of 60%, based on comparison of measured and modelled river nitrogen (Total N) concentrations. Eight subbasins, with net contributions to the river-mouth transport exceeding 3 kg ha−1 yr−1, were identified as the most promising candidates for cost efficient nitrogen management. The other 20 subbasins all had net contributions below 3 kg ha−1 yr−1. Arable land contributed 63% of the nitrogen transport at the river mouth and would thus be in focus for management measures. However, point sources (18% contribution to net transport) should also be considered due to their relatively high accessibility for removal measures (high concentrations). E.g., the most downstream subbasin, with the largest wastewater treatment plant in the whole river basin, had a net contribution of 16 kg ha−1 yr−1. This method for source apportionment may provide authorities with quantitative information about where in a river basin, and at which sources, they should focus their attention. However, once this is done, an analysis with higher resolution has to be performed in each of the interesting subbasins, before decisions on actual management measures can be taken.


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