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1
Rengasamy, P., und KA Olsson. „Sodicity and soil structure“. Soil Research 29, Nr. 6 (1991): 935. http://dx.doi.org/10.1071/sr9910935.
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Sodic soils are widespread in Australia reflecting the predominance of sodium chloride in groundwaters and soil solutions. Sodic soils are subject to severe structural degradation and restrict plant performance through poor soil-water and soil-air relations. Sodicity is shown to be a latent problem in saline-sodic soils where deleterious effects are evident only after leaching profiles free of salts. A classification of sodic soils based on sodium adsorption ratio, pH and electrolyte conductivity is outlined. Current understanding of the processes and the component mechanisms of sodic soil behaviour are integrated to form the necessary bases for practical solutions in the long term and to define areas for research. The principles of organic and biological amelioration of sodicity, as alternatives to costly inorganic amendments, are discussed.
2
Naidu, R., und P. Rengasamy. „Ion interactions and constraints to plant nutrition in Australian sodic soils“. Soil Research 31, Nr. 6 (1993): 801. http://dx.doi.org/10.1071/sr9930801.
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Many of the arable soils in Australia are affected by salinity and/or sodicity. Nutrient deficiency and ion toxicity may occur in both saline and sodic soils. Ho-ever, the mechanism for these constraints on plant growth in sodic soils differs from that of saline soils. Fertility of sodic soils with low nutrient reserves is compounded by the low supply of water and oxygen to roots in profiles with dispersive clays. Nutrient constraints in sodic soils are created by the electron and proton activities (pE and pH) in an environment of degraded soil structure. Australian sodic soils accumulate relatively low levels of organic matter. High sodium, high pH and low biological activity, commonly found in these soils, are not conducive for both the accumulation of organic matter and its mineralization. As a result, these soils are deficient in N and S. Australian soils are highly weathered and have moderate to low reserves of many plant nutrients such as Cu, Mn, Mo, Zn and P. Solubility of phosphorus is generally increased in sodic soils. Poor leaching conditions accumulate boron in soil layers. Higher concentrations of sodium than of calcium in these soils are the major cause of both physical and nutritional problems. Therefore, amelioration of sodicity is the logical first step in improving the chemical fertility of sodic soils. However, fertilizer application and improvement of soil organic matter are essential to increase yields to match the potential yield predictable from climate.
3
Rochester, Ian J. „Phosphorus and potassium nutrition of cotton: interaction with sodium“. Crop and Pasture Science 61, Nr. 10 (2010): 825. http://dx.doi.org/10.1071/cp10043.
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Poor phosphorus (P) and potassium (K) nutrition limits the growth and yield of many cotton (Gossypium hirsutum L.) crops in Australia. The demand for nutrients from cotton crops has risen as yields have increased over the past 40 years, and some soils have become depleted in these nutrients. Cotton is commonly grown on sodic soils that are more prone to nutritional problems. A survey of thirty-one sites over four years in northern NSW, Australia included twelve sites that had sodic topsoil. However, available soil P and K at all sites were above established critical values for cotton crops. Soil sodicity was negatively correlated with available soil P and K, and positively with soil salinity and chloride. Cotton leaf P and K concentrations at flowering were negatively correlated with leaf sodium (Na) concentration. The cotton crops growing in sodic soils produced 20% less dry matter (3 weeks before crop defoliation) and crop P and K uptake was reduced by 23% and 25%, respectively, whereas Na uptake was 107% higher. High soil sodicity also reduced the uptake of micro-nutrients. Two field experiments in adjacent sodic and non-sodic areas on one farm showed a yield response to P fertiliser application at the non-sodic site only, but where soil P availability was above the accepted critical value. Application of K fertiliser did not increase crop K uptake or yield. The lower yield and poorer growth of irrigated cotton on sodic soils was related to higher Na uptake and lower P and K uptake, possibly due to restricted root growth in sodic soils.
4
Sumner, ME. „Sodic soils - New perspectives“. Soil Research 31, Nr. 6 (1993): 683. http://dx.doi.org/10.1071/sr9930683.
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There are large areas of the world where soils are adversely affected by the presence of sodium (Na) as an exchangeable cation. Unlike their saline counterparts which are more extensive, sodic soils have received less attention in the literature. There has been considerable disagreement concerning the definition of sodicity, owing largely to the fact that many experiments used in the development of definitions did not account for the presence of salts in the water used to measure hydraulic properties. These problems are discussed and the conclusion is reached that a single simple definition is no longer possible. This problem is further exacerbated by the fact that many soils which would never have fallen into a previously defined sodic category, do in fact exhibit sodic properties. The major focus of this account of sodicity will therefore be the soils which contain relatively low levels of exchangeable Na. As such soils are widespread in both humid and subhumid areas of the world and are responsible for the production of a large proportion of the world cereal crop, they deserve special attention. Because swelling and dispersion are the primary processes responsible for the degradation of soil physical properties in the presence of Na, an account of clay behaviour in relation to Na and electrolyte concentration is presented before exploring these new realms of sodicity. Pure clay systems are not always suitable for use as models of soil behaviour in terms of dispersion and flocculation. However, as far as swelling is concerned, the correspondence is much better. Nevertheless, the effects of the exchangeable cations on dispersion are predictable albeit usually only qualitatively. This is partly due to the phenomenon of 'demixing' in which the cations are not distributed over all surfaces in the same proportions. The effects of Na and electrolyte concentration in relation to hydraulic conductivity, infiltration, crusting, runoff, erosion and hardsetting are discussed from which it emerges that the effects of Na are manifested in measurable and often sizeable proportions down to very low levels far below those previously used to define sodic soils. The primary processes responsible for physical degradation are swelling at relatively high levels and clay dispersion throughout the range of exchangeable Na percentage (ESP). Provided that the total electrolyte concentration (TEC) is below the critical flocculation concentration (CFC), clays will disperse spontaneously at high ESP values, whereas at lower ESP levels, inputs of energy are required for dispersion. The TEC of the ambient solution, because of its effects in promoting clay flocculation, is crucial in determining soil physical behaviour.
5
Ford, GW, JJ Martin, P. Rengasamy, SC Boucher und A. Ellington. „Soil sodicity in Victoria“. Soil Research 31, Nr. 6 (1993): 869. http://dx.doi.org/10.1071/sr9930869.
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This paper gives a broad overview of the distribution and agricultural importance of sodic soils in Victoria. Sodic soils are estimated to occupy at least 13.4 Mha, representing at least 73% of Victoria's agricultural land. Most of this land is used for dryland farming; about 85% of the cropped land and 66% of the land sown to dryland pastures occurs on sodic soils. The largest sodicity class is 'alkaline sodic', dominated by a diverse range of soils (red duplex, yellow duplex, calcareous earths and self-mulching cracking clays). Alkaline sodic soils comprise half of the total agricultural land area, or about 24% of the area of land currently used for dryland cropping and 21% of the land under sown pasture. Land degradation problems are recognized as affecting most agricultural land in Victoria, and to be substantially limiting its productivity. The nature, extent and severity of the various forms of land degradation are a consequence of both intrinsic soil properties and of management practices. There is an urgent need to improve current farming practices to prevent further deterioration of the soil resource. Existing knowledge of the behaviour of sodic soils under both dryland and irrigated agriculture is reviewed. It is concluded that substantial gains in productivity are possible, but will require effective collaboration between soil scientists, agronomists, and land managers. Collation and integration of current knowledge on the properties and management of sodic soils in Victoria, and the acquisition of additional relevant information by targeted long-term research is required. Key issues for future research are identified.
6
Rengasamy, Pichu. „Soil processes affecting crop production in salt-affected soils“. Functional Plant Biology 37, Nr. 7 (2010): 613. http://dx.doi.org/10.1071/fp09249.
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Salts can be deposited in the soil from wind and rain, as well as through the weathering of rocks. These processes, combined with the influence of climatic and landscape features and the effects of human activities, determine where salt accumulates in the landscape. When the accumulated salt in soil layers is above a level that adversely affects crop production, choosing salt-tolerant crops and managing soil salinity are important strategies to boost agricultural economy. Worldwide, more than 800 million hectares of soils are salt-affected, with a range of soils defined as saline, acidic–saline, alkaline–saline, acidic saline–sodic, saline–sodic, alkaline saline–sodic, sodic, acidic–sodic and alkaline–sodic. The types of salinity based on soil and groundwater processes are groundwater-associated salinity (dryland salinity), transient salinity (dry saline land) and irrigation salinity. This short review deals with the soil processes in the field that determine the interactions between root-zone environments and plant responses to increased osmotic pressure or specific ion concentrations. Soil water dynamics, soil structural stability, solubility of compounds in relation to pH and pE and nutrient and water movement all play vital roles in the selection and development of plants tolerant to salinity.
7
Naidu, R., ME Sumner und P. Rengasamy. „National conference on sodic soils - Summary and conclusions“. Soil Research 31, Nr. 6 (1993): 949. http://dx.doi.org/10.1071/sr9930949.
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Sodic soils cover over 28% of the total land area in Australia. It is clear from the papers delivered at the conference and workshop that sodic soils are beset with serious chemical, physical and nutritional problems. This report summarises these problems based on the discussions during the workshop sessions together with issues raised during group discussion on: (a) distribution, classification and mapping, (b) physical processes, (c) chemical processes, (d) nutrient constraints, (e) biology and organic matter, (f) environmental consequences and (g) management strategies for economically sustainable crop production on sodic soils. The most serious problems raised during the meeting concern inappropriate definition of sodic soils, soil water balance, nutritional requirements on sodic soils, chemical and mineralogical bases of structural instability in relation to amelioration strategies, farming systems to improve organic matter and biological activity, and information transfer. These issues are presented in detail.
8
Silveira, Karien Rodrigues da, Mateus Rosas Ribeiro, Luiz Bezerra de Oliveira, Richard John Heck und Rachel Rodrigues da Silveira. „Gypsum-saturated water to reclaim alluvial saline sodic and sodic soils“. Scientia Agricola 65, Nr. 1 (Februar 2008): 69–76. http://dx.doi.org/10.1590/s0103-90162008000100010.
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Inadequate management of soil and irrigation water contribute to soil degradation, particularly in the alluvial areas of Northeast Brazil, where salinity and sodicity are already common features. This study evaluates the effects of the addition of gypsum in the irrigation water on physical and chemical properties of soils with different levels of salinity and sodicity. Samples were collected at the Custódia irrigation area of Brazil, predominantly covered by alluvial soils. Leaching tests using simulated irrigation water classified as C3S1, and gypsum-saturated irrigation water were carried out in soil columns of 20 and 50 cm depth. Soil leaching with gypsum saturated water (T2) resulted in an increase in the amounts of exchangeable calcium and potassium, and in a decrease of soil pH, in relation to the original soil (T0), with significant statistical differences to the treatment using only water (T1). There was a reduction in the electrical conductivity, exchangeable sodium and exchangeable sodium percentage in both treatments (T1 and T2), with treatment T2 being more effective in the leaching of soil sodium. No changes of electrical conductivity, calcium and pH in depth were observed, but the 20 - 50 cm layer presented higher amounts of magnesium, sodium and exchangeable sodium percentage. Gypsum saturated water improved the hydraulic conductivity in both layers. The use of gypsum in the irrigation water improved soil physical and chemical properties and should be considered as an alternative in the process of reclamation of saline-sodic and sodic soils in Northeast Brazil.
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Cochrane, HR, G. Scholz und AME Vanvreswyk. „Sodic soils in Western Australia“. Soil Research 32, Nr. 3 (1994): 359. http://dx.doi.org/10.1071/sr9940359.
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Sodic soils are common throughout Western Australia, particularly in the south-west agricultural area where they occur mainly as duplex or gradational profiles. Soils with sodic properties are dominant in 26% of the state; saline-sodic sediments and soils in intermittent streams, lakes and estuarine plains occupy a further 5%. Sodic soils are moderately common throughout the south and western portion of the rangeland areas (38% of the state). The south-west coastal sands and the desert and rangeland soils to the north and east of the state are rarely sodic. Although sodicity has been recognized as a discrete problem in W.A. soils since the 1920s, the extent and severity of sodicity has been satisfactorily described only for small areas of the state and most land managers are unaware of the role sodicity plays in limiting the productivity of their soils. Sodicity is implicated in a diversity of problems for both agricultural and non-agricultural uses of Western Australian soils. Subsoil impermeability is probably the most widespread of these, but no comprehensive, quantitative assessment of the influence of exchangeable sodium on subsoil properties has been undertaken. Topsoil sodicity is much less extensive but can severely restrict land productivity, particularly on sandy loam and finer textured soils which set hard when dry. The physical behaviour of Western Australian topsoils cannot usefully be predicted from measurements of exchangeable sodium alone because soils differ so greatly in their response to changing exchangeable sodium. Some remain structurally stable at ESP values >15 while others are so 'sodium-sensitive' that they exhibit highly dispersive behaviour at ESP values as low as 2%. Land values over much of the dryland farming and pastoral areas of W.A. do not justify sustained use of amendments which would reduce soil exchangeable sodium contents. Efficient management of sodic soils in these areas must rely on the prevention of degradation and the use of biological and physical means to maintain adequate soil physical properties. Effective restoration of degraded sodic soils, however, often does require application of inorganic amendments in combination with tillage to initiate structural recovery. Sodicity is currently not considered to be a problem at any of the three main irrigation areas in W.A., but all have sodic soil within their potentially irrigable lands, which may limit their future expansion.
10
Chartres, CJ. „Sodic soils - an introduction to their formation and distribution in Australia“. Soil Research 31, Nr. 6 (1993): 751. http://dx.doi.org/10.1071/sr9930751.
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This paper briefly summarizes existing Australian data about causes of sodicity and the distribution of sodic soils in Australia. Sources of salts and sodium include atmospheric accession, salts released by weathering processes and saline groundwaters. A traditional model of sodic soil pedogenesis is contrasted with more recent data demonstrating the role of several factors including mineralogy, EC/ESP relationships and exchangeable magnesium percentage on development and behaviour of sodic soils. Limited data about the national distribution of sodic soils are presented. There has been very little recent innovative research in Australia to increase understanding of soils affected by sodicity. A number of research needs are indicated.
11
Surapaneni, Aravind. „Preface: Sodicity issues in agricultural industries“. Soil Research 39, Nr. 6 (2001): I. http://dx.doi.org/10.1071/srv39n6_pr.
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Australia is recognised as containing the world�s largest area of sodic soils, with approximately 33% of the continent being affected. The first National Conference and Workshop on Sodic Soils in Australia was held in Adelaide (9�13 November 1992), to bring together information and experience on sodic soils available at that time. The papers from that conference were published as a special issue of the Australian Journal of Soil Research (Volume 31, 1993). The 1992 conference covered a wide range of topics, including distribution, classification, mineralogy, fertility, environmental consequences, irrigation, and management of sodic soils. Importantly, it identified priority areas for research in each of these topics.
12
Bibik, Mykhailo, Hryhorii Moroz, Vitalii Kyrylenko und Artem Kuzmenko. „The problem of the alkalinity degree diagnostics in the soils of the northwest of the Black sea region“. Visnyk of the Lviv University. Series Geography, Nr. 51 (27.12.2017): 21–32. http://dx.doi.org/10.30970/vgg.2017.51.8734.
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According to the results of the study of soils in the Northwest of the Black Sea region, it is determined that here, in the profile of vorony-calcic and calcic Chernozems, both residual and weak alkalinity are manifested. It was found out, nowadays, in the national soil science, there are no clear criteria for the selection of sodic soils and for the determination of their alkalinity degree. Furthermore, there is also the question of the differentiation of the actually sodic and residual-sodic soils. It has been established that on the territory of the Northwest of the Black Sea region polygenetic soils – vorony-calcic and calcic Chernozems weakly and residual-sodic were formed and the diagnostics of their classification and taxonomic position for the moment is rather ambiguous. The diagnostic of the alkalinity degree of vorony-calcic and calcic Chernozems in the Northwest of the Black Sea region was carried out in four methodological approaches. It was established, that it is impossible to carry out precise and unambiguous diagnostics of the alkalinity degree of soils of the territory of the study according to existing methods. Thus, the sodic and residual-sodic soils, according to classification of 1977, are almost entirely positioned as weakly sodic in accordance with the “Field determinant of soils”. In turn, taking into account the Novikova approach, the status of these same soils varies from non-sodic to solonetzes according to the degree of illuviation, the final diagnosis of which, however, contradicts the low content of exchangeable sodium. An integral approach to the determination of the alkalinity degree of soils is proposed, which is based on the chronological features of the course and direction of the sodification process. According to this approach, if the alkalinity of the studied soils is relict, its degree should be diagnosed by the illuviation of silt and by the content of exchange Na+ (Ni> 8 %, Na+<3 % – residual-sodic soils, Ni> 8 %, Na+ ≥ 3 % –sodic soils).In turn, in the case of the modern alkalinity, its degree should be determined by the ratio Ca2+/Mg2+ (<4,8) and by the content of the exchangeable Na+ (<3 % – residual-sodic soils, and ≥3 % – sodic soils). Key words: Chernozems, the alkalinity degree, diagnostic, steppe, the Northwest of the Black Sea region.
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Doyle, RB, und FM Habraken. „The distribution of sodic soils in Tasmania“. Soil Research 31, Nr. 6 (1993): 931. http://dx.doi.org/10.1071/sr9930931.
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It is estimated that sodic soils (ESP>6) occupy at least 23% of Tasmania's land area based on the present limited soil data set. Sodic soils are mostly restricted to lower rainfall areas (<800 mm/y) of eastern Tasmania, occurring primarily in the Launceston Tertiary Basin, the Derwent, Coal, Jordan and Huon River Valleys and on Flinders Island. In Tasmania, sodic soils have formed predominantly from Triassic and Permian mudstones and sandstones, Tertiary clays and unconsolidated Quaternary deposits. However, profiles with sodic features have also developed above granite, Jurassic dolerite and Tertiary basalt. Sodic soils most commonly occur on lowland plains, river terraces and in valley floors. In Tasmania, sodic soils are characterized morphologically by: (i) abrupt separation of a sandy, bleached A2 horizon from a moderately sodic (ESP 6-15) clay subsoil; (ii) coarse prismatic, columnar and/or angular blocky pedality in the subsoil, which may exhibit vertic properties; (iii) hardsetting sandy A2 horizons in some profile classes; (iv) fine sandy crack infills and clay-organic coatings on ped faces in the upper B2 horizon; and (v) thick, sticky and greasy fine clay argillans on ped faces, and clay infills in cracks and other voids in the lower B2 horizon that contribute to reduced porosity and permeability. Sodic soils in Tasmania have traditionally been utilized for pasture production with occasional cultivation for fodder crops and pasture renewal. Under a pastoral system, few sodicity problems have been recognized as such. However, in the last 10 years there has been increased cropping, particularly for poppies and more recently potatoes. Soil structure decline and drainage problems have become key factors limiting production. Management problems are mainly due to poor internal and external drainage, with poor structure in the A2 horizons which liquefy in winter and often set hard in summer. Salinity in associated drainage depressions is a problem gaining increasing recognition.
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Rashid, Muhammad Farhan. „SOIL PHOSPHORUS FRACTIONS AND THEIR TRANSFORMATION IN NORMAL AND SALT AFFECTED SOILS AS AFFECTED BY ORGANIC AMENDMENTS“. Pakistan Journal of Agricultural Sciences 56, Nr. 02 (01.04.2022): 301–12. http://dx.doi.org/10.21162/pakjas/19.8083.
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The soil salinity causes physiological drought resulting in hindrance in the bio-availability of essential nutrients. The interaction between salinity and phosphorus uptake by plants is less explored. Two independent incubation experiments were conducted to study the distribution and transformation of various P fractions in normal and salt affected soils as influenced by various organic amendments application. In first experiment, three different levels of P (200, 400 and 600 mg kg-1 of soil) were applied in three soils differing in soil EC and SAR. Changes in various fractions of soil P (Ca2-P, Ca8-P, Al-P, Fe-P, Olsen-P) were estimated at different time intervals. All three soils behaved differently for P distribution among various fractions. Maximum available P (12.18 mg kg-1 ) was found in PROKA soil (saline sodic) at 400 mg kg-1 of P applied. In 2nd experiment, various organic amendments [farmyard manure (FYM), poultry manure (PM), crop residue (CR)] and sewage sludge (SS) were used, with and without adding P fertilizer @ 400 mg kg-1 to study their effect on changes in soil P, at different time intervals. Plant available Olsen-P fraction significantly increased after 90 days in all soils (normal, saline sodic, marginal saline sodic) with amendments FYM and PM but not as much with amendments CR and SS. Overall, increase in Olsen-P was higher with PM (23.2, 21.7 and 19.4 mg kg-1) and FYM (20.6, 17.6 and 20.6 mg kg-1) as compared with SS (14.3, 15.5 and 15.7 mg kg-1) and CR (12.9, 14.4 and 14.0 mg kg-1) in normal, saline sodic and marginal saline sodic soils, respectively. On the basis of these results, it was concluded that integration of PM and FYM with P level 400 mg kg-1 is an effective approach to mobilize more P available for plant uptake in normal and salt-affected soils with order of normal> saline sodic> marginal saline sodic.
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Mahdy, A. M. „Comparative effects of different soil amendments on amelioration of saline-sodic soils“. Soil and Water Research 6, No. 4 (28.11.2011): 205–16. http://dx.doi.org/10.17221/11/2011-swr.
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A greenhouse experiment was conducted to test the potential of different soil amendments in saline-sodic soils reclamation; to affect the growth response of alfalfa (Medicago sativa L.) plants grown on two saline-sodic soils; and to evaluate the comparative efficiency of different soil amendments for their effects on salinity, sodicity, and pH levels of the soils. To achieve these objectives, two highly saline-sodic soils were selected (Abees, Typic torrifluvents and Elhammam, Typic calciorthids). Different soil amendments were used (compost, anthracite coal powder, water treatment residuals, ferrous sulphate, and a combination of them). The results of the study indicated that pH of Elhammam soil was less affected than pH of Abees soil after the amendment application because of the high calcium carbonate content which acted as a buffer and resisted any appreciable change in soil pH in the alkaline range. The positive effects of all treatments followed the order: T16 > T12 > T13 > T14 = T5 > T11 = T15 > T7 > T8 > T4 = T6 > T9 = T10 > T2 >T3> T1 >T0. The most effective amendment in reducing SAR<sub>e </sub>in the experimental soils was T16. This was due to the presence of Al in WTRs and Fe in ferrous sulphate which enhanced the leaching process, and the presence of high adsorptive capacity materials like WTRs and compost which adsorb more sodium. The positive effects of all treatments for reducing SAR<sub>e</sub> in Abees soil followed the order: T16 > T15 > T14 > T13 > T11 > T12 .While, in Elhammam soil, the order was: T16 > T15 > T14 > T13 = T11>T12 = T5. The removal sodium efficiency (RSE) or percentage of Na-removed from the soils at the end of the experiment was significantly reduced after the application of the amendments. RSE of T16 proved the highest value (76%) among the treatments for the two soils used, followed by T15 and T14. The yield of biomass at T16 significantly increased, the increase being 959% in comparison with T0 in Abees soil, while the increase in biomass yield was 1452% in comparison with T0 in Elhammam soil. However, field tests are necessary to draw the final conclusions.
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Novák, Tibor. „Afforestation affects vertical distribution of basic soil characteristics and taxonomic status of sodic soils“. Plant, Soil and Environment 68, No. 5 (27.05.2022): 245–52. http://dx.doi.org/10.17221/53/2022-pse.
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Afforestation, settled before 60–90 years and adjacent solonetzic grasslands, representing the natural vegetation cover were compared in this study based on their basic soil characteristics (pH, CaCO3 content, soil organic carbon (SOC), and exchangeable sodium percentage (ESP)) up to 2 m depth. The assumption was that the plantings of arbour vegetation can change soil characteristics of sodic soils not only in superficial layers but even in larger depths. Grasslands and forest soils were compared by standardised depths. Afforested soils showed lower pH in the depth at 0–100 cm, and slightly higher SOC content in subsoil (20–100 cm). CaCO3 content was significantly different (higher) only at the depth of 50–100 cm in afforested soils. Remarkable differences in ESP values were measured. Afforestation had in almost every layer (0–20, 20–50, 50–100 and 150–200 cm) a significant lower ESP value than grassland soil samples from the same depths. As the value of the ESP is relevant from soil classification purposes as well, the leaching of sodium also can change the taxonomic status of the soils from soils with natric horizon, to soils with Sodic or Bathysodic qualifiers.
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Sanchez, C. A. „1063 CONSIDERATIONS IN THE MANAGEMENT OF SALINE AND SODIC SOILS FOR THE PRODUCTION OF HORTICULTURAL CROPS“. HortScience 29, Nr. 5 (Mai 1994): 581a—581. http://dx.doi.org/10.21273/hortsci.29.5.581a.
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Approximately 33% of all irrigated lands worldwide are affected by varying degrees of salinity and sodicity. Soils with an electrical conductivity (EC) of, the saturated extract greater than 4 dS/m are considered saline, but some horticultural crops are negatively impacted if salt concentrations in the rooting zone exceed 2 dS/m. Salinity effects on plant growth are generally considered osmotic in nature, but specific ion toxicities and nutritional imbalances are also known to occur. In addition to direct toxic affects from Na salts, Na can negatively impact soil structure. Soils with exchangeable sodium percentages (ESPs) or saturated extract sodium absorption ratios (SARs) exceeding 15 are considered sodic. Sodic soils tend to deflocculate, become impermeable to water and air, and have a strong tendency to puddle. Some soils are both saline and sodic. This workshop presentation will summarize various considerations in the management of saline and sodic soils for the production of horticultural crops.
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Bethune, M. G., und T. J. Batey. „Impact on soil hydraulic properties resulting from irrigating salinesodic soils with low salinity water“. Australian Journal of Experimental Agriculture 42, Nr. 3 (2002): 273. http://dx.doi.org/10.1071/ea00142.
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Irrigation-induced salinity is a serious problem facing irrigated areas in the Murray–Darling Basin of Australia. Groundwater pumping with farm re-use for irrigation is a key strategy for controlling salinity in these irrigation areas. However, the re-use of highly saline–sodic groundwater for irrigation leads to accumulation of sodium in the soil profile and can result in sodic soils. Leaching of saline–sodic soils by winter rainfall and low salinity irrigation waters are 2 management scenarios likely to exacerbate sodicity problems. Characteristic to sodic soils is poor soil structure and potentially reduced soil permeability. Two indicators of soil permeability are infiltration rate and hydraulic conductivity. A replicated plot experiment was conducted to examine the long-term impact of irrigation with saline–sodic water on soil permeability. High levels of soil sodicity (ESP up to 45%) resulted from 10 years of saline irrigation. Over this period, leaching by winter rainfall did not result in long-term impacts on soil hydraulic properties. Measured soil hydraulic properties increased linearly with the salinity of the applied irrigation water. Leaching by irrigating with low salinity water for 13 months decreased soil salinity and sodicity in the topsoil. The resulting reduction in steady-state infiltration indicates soil structural decline of the topsoil. This trial shows that groundwater re-use on pasture will result in high sodium levels in the soil. Sodicity-related soil structural problems are unlikely to develop where there is consistent groundwater irrigation of pasture. However, structural decline of these soils is likely following the cessation of groundwater re-use.
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Nelson, P. N., J. A. Baldock und J. M. Oades. „Changes in dispersible clay content, organic carbon content, and electrolyte composition following incubation of sodic soil“. Soil Research 36, Nr. 6 (1998): 883. http://dx.doi.org/10.1071/s98024.
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Measurement of dispersible clay is important for the diagnosis of structural stability problems in soil. However, clay dispersibility is known to change with water content and time. The purpose of the present study was to determine how incubation of sodic soil under different water content regimes influences clay dispersibility. Two topsoils (depth 0-0·1 m), one sodic [exchangeable sodium percentage (ESP) 9 · 7] and the other non-sodic (ESP 3·8), were collected from an experimental pasture at Kyabram, Victoria, and 2 soils, a sodic topsoil (depth 0-0·1 m, ESP 6·9) and the corresponding subsoil (depth 0·2-0 m, ESP 25·7), were collected from a cropped field at Two Wells, South Australia. The soils were incubated for 264 days in a split-plot design. The main treatments were soil type and incubation water content: continuously air-dry, continuously wet (-50 kPa), or with wet/dry cycles. The subtreatment was water content at analysis: air dry or wet (-50 kPa). Clay dispersion was greater when measured on wet soils than dry soils, irrespective of water contents during the prior incubation. Electrical conductivity increased, and sodium adsorption ratio (SAR), pH, and organic carbon content decreased as a function of the time for which the soils were wet. In the Kyabram soils that were wet when analysed, easily dispersible clay content increased with SAR. Decreases in moderately dispersible clay under the wetting/drying regime were not related to electrolyte composition, and were attributed to particle rearrangement and cementation. The decreases in clay dispersibility with time occurred despite net losses of carbohydrate and aliphatic materials. An implication of the work is that the decomposition of soil organic matter, even in the absence of fresh additions, may reduce clay dispersion in sodic soils by altering electrolyte concentration and composition.
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Singh, Balwinder, und M. S. Bajwa. „Studies on the leaching of urea in sodic soils“. Journal of Agricultural Science 106, Nr. 2 (April 1986): 323–30. http://dx.doi.org/10.1017/s0021859600063917.
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SUMMARYLaboratory experiments were conducted in PVC columns to study the leaching and transformation of applied urea in sodic soils (Gharachon loam-Aquic Natrustalf and Domeli silty clay loam-Aquic Camborthid) reclaimed by gypsum application and kept submerged for 7 or 14 days after fertilizer application. The effect of different depths of irrigation water (5, 7·5, 10, 20 and 30 cm) on urea leaching was studied in a sandy loam sodic soil. In another experiment, the effect of time interval (0 or 4 days) between urea application and initiation of submergence with distilled water (for 7 or 14 days) was investigated involving two recently reclaimed sodic soils (Gharachon loam and Domeli silty clay loam). The results showed that the extent of urea leaching mainly depended upon soil texture. In Domeli silty clay loam, urea penetrated to 20 cm depth with peaks in concentration at 12·5 cm at both 7 and 14 days of submergence. In Gharachon loam urea-N moved to 25 cm depth after 7 days and to 35 cm after 14 days. In the sandy loam sodic soil peaks of urea-N concentration were observed at 12·5, 22·5 and 27·5 cm depths after infiltration of 5, 7·5 and 10 cm depth of water, respectively. Leaching with 20 and 30 cm depths of water moved urea deeper (below 50 and 70 cm, respectively). In recently reclaimed soils, leaching initiated immediately after fertilizer application displaced urea to slightly deeper layers compared with leaching initiated 4 days after urea application. Leaching may not be an important loss mechanism of urea-N in loam or silty clay loam sodic soils. However, in light-textured sandy loam sodic soils leaching beyond the root zone can be expected to create fertilizer management problems.
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Shaw, R., L. Brebber, C. Ahern und M. Weinand. „A review of sodicity and sodic soil behavior in Queensland“. Soil Research 32, Nr. 2 (1994): 143. http://dx.doi.org/10.1071/sr9940143.
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The occurrence of sodic soils in Queensland is more related to soil genetic factors of the past than to the current rainfall pattern, with lower sodium accessions and smaller occurrence of saline lands than other areas of Australia. A soil sodicity map of Queensland is presented. On an area basis, 55% of soils in Queensland are non-sodic, 25% are strongly sodic and 20% are of variable sodicity. The map was prepared using exchangeable sodium percentage (ESP) values at 0.6 m depth from 2 009 soil profiles, as well as the soil boundaries of the 1:2000000 Atlas of Australian Soils maps (Northcote et al. 1960-68). There is general agreement with the earlier sodicity map of Northcote and Skene (1972). The relationships between exchangeable sodium and field-measured soil hydraulic properties and plant-available water capacity are discussed. Behaviour of sodic soils depends on the exchangeable sodium percentage, clay content, clay mineralogy and salt levels. The binary component particle packing theory has been used to explain soil behaviour and identify those soils most susceptible to sodium. Cracking clay soils with dominantly smectite mineralogy and high clay contents are less susceptible to a given ESP level, as determined by their hydrological behaviour, than soils of moderate clay content and mixed mineralogies. The sodicity and the salt content of an irrigation water are important in maintaining permeability of soils. The naturally occurring equilibrium salinity-sodicity relationships of a wide range of subsoils in Queensland is compared to the published relationships between stable permeability and decreasing permeability based on sodicity and salt content. Aspects of management of sodicity under dryland and irrigation are discussed.
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Rengasamy, P., und KA Olsson. „Irrigation and sodicity“. Soil Research 31, Nr. 6 (1993): 821. http://dx.doi.org/10.1071/sr9930821.
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The productivity of irrigated agriculture in Australia is low for most crops and one important factor is the physical and chemical constraints caused by sodicity in the rootzone. Over 80% of the irrigated soils are sodic and have degraded structure limiting water and gas transport and root growth. Irrigation, without appropriate drainage, leads to the buildup of salts in soil solutions with increased sodium adsorption ratio (SAR) and can develop perched watertables due to a very low leaching fraction of the soil layers exacerbated by sodicity. Therefore, irrigation management in Australia is closely linked with the management of soil sodicity.The inevitable consequence of continued irrigation of crops and pastures with saline-sodic water without careful management is the further sodification of soil layers and concentration of salt in the rootzone. This will increase the possibility of dissolving toxic elements from soil minerals. The yields of crops can be far below the potential yields determined by climate. The cost of continued use of amendments and fertilizers to maintain normal yields will increase under saline-sodic irrigation. Most of the irrigated soils in Australia need reclamation of sodicity of soil layers at least in the rootzone. The management of these sodic soils involves the application of gypsum, suitable tillage and the maintenance of structure by the buildup of organic matter and biological activity aver time. Then artificial drainage, an essential component of the management of irrigated sodic soils, is possible. By following these soil management practices, irrigated agriculture in Australia will become sustainable with increased yields and high economic returns.
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Sibbett, G. Steven. „Managing High pH, Calcareous, Saline, and Sodic Soils of the Western Pecan-growing Region“. HortTechnology 5, Nr. 3 (Juli 1995): 222–25. http://dx.doi.org/10.21273/horttech.5.3.222.
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Pecan [Carya illinoinensis (Wangenh. K. Koch)] soils in the arid western United States are characteristically high in pH, calcareous, and often saline or sodic. Economic production, when trees are grown in such soils, requires that growers pay particular attention to managing soil chemistry to avoid nutrient deficiencies, toxicities, or water deficits due to soil structural deterioration. Soil-applied acidulents, calcium-containing compounds, and water management are used by growers to manage high pH problems, sodic soil conditions, and salinity.
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ANGIN, Ilker, Ahmet GURLEK und Serdar SARI. „THE USABILITY OF HYDROGEL IN INCREASING THE EFFICIENCY OF GYPSUM APPLIED TO SALINE-SODIC SOILS“. Carpathian Journal of Earth and Environmental Sciences 16, Nr. 1 (2021): 93–115. http://dx.doi.org/10.26471/cjees/2021/016/158.
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This study aimed at the assessment of the usability of hydrogel in increasing the efficiency of gypsum applied to saline-sodic soils. The experiment was conducted under laboratory conditions in disturbed soil columns and was set-up in a completely randomized design with six hydrogel application rates (Control, 0.05%, 0.10%, 0.15%, 0.20% and 0.25% weight/weight (w/w) basis) and with three replications. Hydrogel application to saline-sodic soil had significant effects on leachate pH. The highest leachate pH’s were found in the final leachates in the order of 0.05%>0.10%>0.15%, as 9.12, 9.09, and 9.03, respectively. In all of the application rates tested, the highest electrical conductivity (EC) and Na+ leachate losses were obtained after first pore volume of leaching and then decreased gradually with further leaching. Relative to the control, hydrogel application in the rate of 0.05% increased the leaching of Na+ by 8.1% on total. However, due to the absence of statistically significant effects of the treatments on Na+ leaching, an improvement in soil exchangeable sodium percentage (ESP) and pH in saturation extract (pHe) values as an indicator of reclamation was not proven. Use of gypsum together with hydrogel increased saturated hydraulic conductivity of soils in the rates of 28.6%-42.6%, which is especially important for reducing the duration for amelioration of saline-sodic soils. Application of hydrogel to saline-sodic soils along with gypsum can be an efficient management option not only for reducing the risk of physiological drought, but also for reducing the amount of time to reclaim saline-sodic soils.
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Abdalla Sabtow, Hassan, und Fatih Mehmet Kızıloğlu. „Stabilize Kent Çamuru ve Jips Uygulanmış Tuzlu Sodyumlu Topraklarda Arıtılmış Atıksuyun Islanma-Kuruma Döngülerinin Hidrolik İletkenliğe Etkisi“. Turkish Journal of Agriculture - Food Science and Technology 10, Nr. 9 (09.10.2022): 1741–46. http://dx.doi.org/10.24925/turjaf.v10i9.1741-1746.5435.
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This study was carried out to determine changes in hydraulic conductivity of a saline sodic soil subjected to different wetting-drying cycles and treated wastewater after stabilized sludge sewage and gypsum application. In a factorial experimental design, the study was conducted with three replication by using 3 treatment sewage sludge doses (50, 100 and 150 t ha-1), 3 wetting-drying cycles (0, 7 and 14 days) and 2 different water types (fresh water and treated wastewater). The hydraulic conductivity values of the saturated saline-sodic soils were measured at 2, 12 and 24 hour intervals by using a constant level ICW laboratory permemeter. The increase in the applied treatment sludge dose significantly affected the hydraulic conductivity value of the soils and significantly depending on the measurement range. It was determined that irrigation waters have different properties caused a significant change in the hydraulic conductivity value of the soils, with measurements made at intervals of 2 and 24 hours. Depending on the measurement interval, it was determined that the increase in sewage sludge doses caused significant effect and very important on the soil hydraulic conductivity. The study results indicated that the application of gypsum and stabilized waste sludge to the soil cause an increase in hydraulic conductivity values. The study results indicated that the application of gypsum and sewage sludge to the soil cause an increase in hydraulic conductivity values of saline sodic soils. The study results also showed that treated wastewater containing low amount of suspended solids can be used safely for irrigation on the land have saline-sodic soils. The study result also indicated that by applying solid and liquid wastes obtained from treatment units to the saline-sodic soils can be significant contribution in terms of waste management and environmental protection.
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Evans, C. M., und B. J. Scott. „Surface soil acidity and fertility in the central-western wheatbelt of New South Wales“. Australian Journal of Experimental Agriculture 47, Nr. 2 (2007): 184. http://dx.doi.org/10.1071/ea04165.
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Documentation of the chemical fertility status of the soils is sparse for the western and central-western wheatbelt of New South Wales, Australia. We examined properties of the surface soils (0–10 cm) from central-western NSW by collating two published and nine unpublished datasets of soil analyses representing about 2800 soil samples. The emphasis was on the red soils used extensively for cropping. The surface soils of central-western NSW have low phosphorus (47% of soils) and sulfur (70% of soils <5 mg S/kg using KCl-40 analysis) status and commonly have organic carbon contents of about 1%. Surface soil acidity was a substantial problem with 56% of soils (0–10 cm) having a pHCa <5.0. Sodic and dispersive soils are also of concern in this area and these soils have received little attention or research. Approximately 5% of surface (0–10 cm) soils had an exchangeable sodium percentage of ≥6% (sodic). Salinity of surface soils was of minor significance compared with other soil problems in the area, although isolated areas occur. These results indicated that lime applications in this area are likely to benefit crop and pasture production. Additional use of phosphorus and sulfur fertilisers and agricultural practices which increase or maintain organic carbon will also need to be adopted to improve pasture and crop production. The use of gypsum and/or lime on sodic soils may also need to be addressed. As a priority, we suggest that the benefits of lime application to crop yield be examined. The application of lime to the 0–10 cm soil depth should ultimately arrest acidification of the subsurface soil (10–20 cm depth) through downward movement of the lime effect. Further examination of gypsum applications to dispersive sodic soils and the evaluation of sulfur deficiency in the field for pastures and canola are also priority areas of likely agricultural relevance.
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Rengasamy, P. „Transient salinity and subsoil constraints to dryland farming in Australian sodic soils: an overview“. Australian Journal of Experimental Agriculture 42, Nr. 3 (2002): 351. http://dx.doi.org/10.1071/ea01111.
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More than 60% of the 20 million ha of cropping soils in Australia are sodic and farming practices on these soils are mainly performed under dryland conditions. More than 80% of sodic soils in Australia have dense clay subsoils with high sodicity and alkaline pH (>8.5). The actual yield of grains in sodic soils is often less than half of the potential yield expected on the basis of climate, because of subsoil limitations such as salinity, sodicity, alkalinity, nutrient deficiencies and toxicities due to boron, carbonate and aluminate. Sodic subsoils also have very low organic matter and biological activity. Poor water transmission properties of sodic subsoils, low rainfall in dryland areas, transpiration by vegetation and high evaporation during summer have caused accumulation of salts in the root zone layers. This transient salinity, not influenced by groundwater, is extensive in many sodic soil landscapes in Australia where the watertable is deep. ‘Dryland salinity’ is currently given wide attention in the public debate and in government policies, but only focusing on salinity induced by shallow watertables. While 16% of the dryland cropping area is likely to be affected by watertable-induced salinity, 67% of the area has a potential for transient salinity not associated with groundwater and other subsoil constraints and costing the Australian farming economy in the vicinity of A$1330 million per year. A different strategy for different types of dryland salinity is essential for the sustainable management and improved productivity of dryland farming. This paper discusses the sodic subsoil constraints, different types of salinity in the dryland regions, the issues related to the management of sodic subsoils and the future priorities needed in addressing these problems. It also emphasises that transient salinity in the root zone of dryland agricultural soils is an important issue with potential for worse problems than watertable-induced seepage salinity.
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Rajammal, Sherene Jenita, T, S. Maragatham und R. Santhi. „Development of Soil Test based Fertilizer Prescription Equations under IPNS for Rice in Salt affected soils of Tamil Nadu“. YMER Digital 21, Nr. 03 (02.03.2022): 01–10. http://dx.doi.org/10.37896/ymer21.03/01.
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Soil Test Crop Response - Integrated Plant Nutrition System (STCR - IPNS) technology in restoring soil fertility in sodic soil was well established in this study. STCR -IPNS correlation studies were conducted with rice in black calcareous sandy clay loam (Vertic Ustropept) sodic soils of Tamil Nadu, Southern India during 2019 – 2021and fertilizer prescription equations under Integrated Plant Nutrition System (IPNS) were developed. A ready reckoner of fertilizer doses at varying soil test values, for attaining 6 and 6.5 t ha-I target grain yield of rice has been worked out. Using these equations, test verification trials were conducted on farmer's holding in Manikandam block of Tiruchirapalli district. The per cent achievement of the targets aimed was more than 90 indicating the validity of the equations for prescribing fertilizer doses for rice under sodic soils. The STCR -IPNS treatments recorded relatively higher response ratio (RR) and benefit - cost ratio (BCR) over blanket, STCR - NPK alone treatments and farmer's practice. Post-harvest soil tests for NPK revealed that there was maintenance of soil fertility under sodic soil.
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Kalra, Yash P. „Determination of pH of Soils by Different Methods: Collaborative Study“. Journal of AOAC INTERNATIONAL 78, Nr. 2 (01.03.1995): 310–24. http://dx.doi.org/10.1093/jaoac/78.2.310.
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Abstract Fifty-three laboratories (including author’s) from Canada, India, Israel, and the United States participated in a collaborative study for the measurement of pH of different types of soils. A method with 2 alternative procedures was used for pH measurements of mineral soils (alternative I for soils containing less than 17⋊ organic carbon and alternative II for soils with variable salt content), a second method was used for saline-sodic soils, and a third method was used for organic soils (soils containing at least 17⋊ organic carbon). The pH was measured potentiometricaIly. The methods were selected by the Soil Science Society of America, S889 Committee on Coordination of Official Methods of Soil Analysis. Each laboratory used all 4 procedures to analyze 10 blind duplicate samples per procedure. The repeatability relative standard deviation values (RSDr) were 1.45–7.80% for mineral soils tested by the alternative 1,0.95–6.91% for mineral soils tested by the alternative II, 0.74–7.09% for saline-sodic soils, and 0.73–4.66% for organic soils. The corresponding reproducibility relative standard deviation (RSDR) values were 2.67–10.75%, 2.03–7.54%, 2.45–9.93%, and 2.15–6.32%. Repeatability and reproducibility data indicated that the results are within acceptable levels. The 3 methods for pH measurements of mineral, saline-sodic, and organic soils were adopted first action by AOAC INTERNATIONAL.
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Gonçalo Filho, Francisco, Nildo da Silva Dias, Stella Ribeiro Prazeres Suddarth, Jorge F. S. Ferreira, Ray G. Anderson, Cleyton dos Santos Fernandes, Raniere Barbosa de Lira, Miguel Ferreira Neto und Christiano Rebouças Cosme. „Reclaiming Tropical Saline-Sodic Soils with Gypsum and Cow Manure“. Water 12, Nr. 1 (21.12.2019): 57. http://dx.doi.org/10.3390/w12010057.
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Saline-sodic soils are a major impediment for agricultural production in semi-arid regions. Salinity and sodicity drastically reduce agricultural crop yields, damage farm equipment, jeopardize food security, and render soils unusable for agriculture. However, many farmers in developing semi-arid regions cannot afford expensive amendments to reclaim saline-sodic soils. Furthermore, existing research does not cover soil types (e.g., Luvisols and Lixisols) that are found in many semi-arid regions of South America. Therefore, we used percolation columns to evaluate the effect of inexpensive chemical and organic amendments (gypsum and cow manure) on the reclamation of saline-sodic soils in the northeast of Brazil. Soil samples from two layers (0–20 cm and 20–40 cm in depth) were collected and placed in percolation columns. Then, we applied gypsum into the columns, with and without cow manure. The experiment followed a complete randomized design with three replications. The chemical amendment treatments included a control and four combinations of gypsum and cow manure. Percolation columns were subjected to a constant flood layer of 55 mm. We evaluated the effectiveness of sodic soil reclamation treatments via changes in soil hydraulic conductivity, chemical composition (cations and anions), electrical conductivity of the saturated soil-paste extract, pH, and the exchangeable sodium percentage. These results suggest that the combined use of gypsum and cow manure is better to reduce soil sodicity, improve soil chemical properties, and increase water infiltration than gypsum alone. Cow manure at 40 ton ha−1 was better than at 80 ton ha−1 to reduce the sodium adsorption ratio.
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., M. Anwar Zaka, Fakhar Mujeeb ., Ghulam Sarwar ., N. M. Hassan . und G. Hassan . „Agromelioration of Saline Sodic Soils“. Journal of Biological Sciences 3, Nr. 3 (15.02.2003): 329–34. http://dx.doi.org/10.3923/jbs.2003.329.334.
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Dodd, K., C. N. Guppy, P. V. Lockwood und I. J. Rochester. „Impact of waterlogging on the nutrition of cotton (Gossypium hirsutum L.) produced in sodic soils“. Crop and Pasture Science 64, Nr. 8 (2013): 816. http://dx.doi.org/10.1071/cp13093.
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Sodicity in Vertosols used for agricultural production can adversely affect the growth and nutrition of cotton (Gossypium hirsutum L.) plants. Cotton produced in sodic soils has reduced dry matter and lint yield and can develop toxic plant tissue concentrations of sodium (Na) but limited tissue concentrations of phosphorus (P,) potassium (K), and micronutrients. Crops produced on sodic soils frequently suffer from aeration stress after an irrigation or rainfall event, and it was hypothesised that the adverse physical and/or chemical conditions of sodic soils may exacerbate the effects of waterlogging. We measured the impacts of sodicity on the growth, nutrition, and root recovery time of cotton during and after waterlogging in two experiments. In the first, cotton plants were subjected to a 7-day period of inundation in Grey Vertosols with a range of exchangeable sodium percentage (ESP) values from 2 to 25%; 32P was placed in the pots and its accumulation in the plant was used to indicate root activity and recovery after the waterlogging event. In a second experiment, agar was dissolved in nutrient solutions with a range of Na concentrations (9, 30, and 52 mm) matching soil solution Na concentrations in sodic soils, in order to simulate a waterlogging event. Following the waterlogging event, the solutions were labelled with 32P, in order to determine the effect of sodic soil solution chemistry on the rate of recovery of cotton root function after the event. Plant nutrient analysis was used to determine the effects of sodicity and waterlogging on cotton nutrition. In both experiments, waterlogging reduced root activity and reduced the uptake and transport of labelled P by the cotton plants, decreased plant P and K concentrations, and increased the plant Na concentrations. Sodicity exacerbated the effects of waterlogging on root function and cotton nutrition in the soil experiment but not in the nutrient solution experiment, suggesting that any contribution of waterlogging to the patterns of nutrient accumulation in cotton crops produced in sodic fields occurs due to soil physical factors rather than soil solution chemistry.
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Mahmood, Khalid, Kauser A. Malik, M. A. K. Lodhi und Khalid Hamid Sheikh. „Soil–Plant Relationships in Saline Wastelands: Vegetation, Soils, and Successional Changes, During Biological Amelioration“. Environmental Conservation 21, Nr. 3 (1994): 236–41. http://dx.doi.org/10.1017/s037689290003321x.
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An ecological survey of undisturbed saline wastelands and adjacent fields of Kallar Grass (Leptochloa fusca) was undertaken to study species distribution in relation to soil conditions and changes in species composition during amelioration processes. Five plant communities, represented by Atriplex crassifolia C.A. Mey., Cynodon dactylon (L.) Pers., Desmostachya bipinnata (L.) Stapf, Suaeda fruticosa (L.) Forssk., and Eleusine flagellifera Nees, had colonized undisturbed areas. Soils of plant communities dominated by these species showed significant variations in salinity and sodicity. S. fruticosa was dominant on highly saline–sodic soil, Cynodon on slightly saline and moderately sodic soil, whereas D. bipinnata showed little variation in cover percentage with changes in salinity and sodicity of soil. These three species had wide ecological amplitude compared with E. flagellifera and A. crassifolia, which were restricted to non-saline and marginally saline–sodic soils, respectively.
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Zhurba, Viktor, Yevgeniy Chayka, Natalya Gucheva, Dmitry Ushakov, Natia Ugrekhelidze, Natalia Kulikova und Marina Egyan. „Modern Technologies of Alkalized and Sodic Soils Reclamation“. E3S Web of Conferences 135 (2019): 01087. http://dx.doi.org/10.1051/e3sconf/201913501087.
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The technology of desalination of fine-textured soils using deep tillage, leaching operations and chemical reclamation agents includes the calculation of doses of ameliorants and leaching requirements, methods and timing of reclamation, soil treatment, selection of crops, and the need for fertilizers on reclamation lands. The stages of preparation of the fields before the application of ameliorants are reviewed. Initially, the fields are divided into lots, the location of loose ameliorants clamps is determined. The options for overall and selective land reclamation are considered. When conducting selective reclamation, it is necessary to locate the solonetzic spots and mark them with range poles. The options for cultivating the soil of irrigated lands characterized by increased density of the subsurface soil horizon of more than 1.4 t/m3 are reviewed. The most pressed are the solonetzic soils with a poor structure or without it. The most preferred methods of cultivating degraded soils (deep loosening or plowing) are identified, which are one of the necessary techniques to provide the greatest depth, degree and speed of soil desalinization. The options for leaching of chloride-sulfate loamy soils, chloride-sulfate salinization and soda salinization are considered.
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Fan, Yuan, Wuyan Shen und Fangqin Cheng. „Reclamation of two saline-sodic soils by the combined use of vinegar residue and silicon-potash fertiliser“. Soil Research 56, Nr. 8 (2018): 801. http://dx.doi.org/10.1071/sr18074.
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Amelioration of saline-sodic soil is essential to increase crop production and preserve the ecological environment in arid and semiarid regions. In this study, a pot experiment was conducted to investigate the effect of combined use of vinegar residue and silicon-potash (Si-K) fertiliser on the physical and chemical properties of two calcareous saline-sodic soils (saline soil (H-soil) and saline-sodic soil (S-soil)) and the growth of oat plants. The results showed that soil electrical conductivity was significantly decreased when vinegar residue was applied in two soils, which could be attributed to that vinegar residue could release H+, and react with HCO3−. When the combination of vinegar residue and Si-K fertiliser were used, equilibrium condition between monovalent cations and divalent cations could be altered. The divalent cations (e.g. Ca2+, Mg2+) were adsorbed at the cost of monovalent cations (Na+), resulting in the reduction of sodium adsorption ratio in the two soils. The decrease in soil pH was mainly due to the decrease in the activity of CO32− and HCO3−, which would react with H+ while vinegar residue was applied. As a saline-sodic soil, S-soil exhibited larger decrease in the pH compared with H-soil, a saline soil. The increase in the relative weight of wet stable macro-aggregate could be attributed to the release of Ca2+ and H+ and the flocculation of the dispersed clay by the application of Si-K fertiliser and vinegar residue. The application of Si-K fertiliser and vinegar residue contributed to a significant increase in survival rate and plant height of oat plants. It also led to increased relative water content and reduced electrolyte leakage for oat plants. This could be ascribed to the improvement of soil aggregate structure and nutrient supply, which promoted selective absorption and transportation of K+ over Na+ and decreased leaf damage. Therefore, the combined use of vinegar residue and Si-K fertiliser was considered to be a wise method for ameliorating two calcareous saline-sodic soils in Shanxi Province, Northern China.
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Kelsey, Patrick, und Richard Hootman. „Soil Resource Evaluation for a Group of Sidewalk Street Tree Planters“. Arboriculture & Urban Forestry 16, Nr. 5 (01.05.1990): 113–17. http://dx.doi.org/10.48044/jauf.1990.030.
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Urban street-tree-planter soils provide inadequate growing space for root systems of trees and are subject to increased concentrations of pollutants not typically found in native soils. An examination of planting media in selected Geneva, Illinois street tree planters revealed physical and chemical soil properties that Only the most stress-tolerant species could endure. The planter soils generally consisted of brick rubble, gravel, sand, and cinders. Drainage in the planters was impeded due to textural discontinuities. Soil pH and sodium values were high enough to classify these soils as sodic. Sodic soils naturally occur in arid and semi-arid regions where evapotranspiration exceeds precipitation. Planter soils need testing for physical and chemical characteristics before being used for trees. They can then be modified, if necessary, to provide the plant with the best possibilities to survive the urban environment.
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Artiola, Janick F., Heluf Gebrekidan und David J. Carty. „Use of langbeinite to reclaim sodic and saline sodic soils“. Communications in Soil Science and Plant Analysis 31, Nr. 17-18 (Oktober 2000): 2829–42. http://dx.doi.org/10.1080/00103620009370631.
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Thamaraiselvi, R,, und K. Arulmozhiselvan. „Fixation of soluble forms of fertilizer phosphorus in salt affected soils of Ramanathapuram and Trichy districts and acid soil of Ariyalur district of Tamil Nadu“. Journal of Applied and Natural Science 12, Nr. 2 (10.06.2020): 213–20. http://dx.doi.org/10.31018/jans.vi.2284.
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Soluble phosphorus (P) applied through phosphatic fertilizers is quickly converted into low soluble P compounds in soil. For evaluating fixation ability of P fertilizers laboratory incubation experiments were conducted with saline, sodic and acid soils. Phosphatic fertilizers selected were single super phosphate (SSP), diammonium phosphate (DAP), monoammonium phosphate (MAP), monopotassium phosphate (MPP) and 19:19:19 N, P2O5, K2O % (All-19). Fixation of P was computed based on the amount of P recovered after addition of P in the soil in increasing levels. At a typical P addition at 16 kg ha-1 the results were compared in all soils. In saline soil, high fixation of P occurred when DAP (12.18 kg ha-1) and MPP (11.28 kg ha-1) were applied. In sodic soil, high fixation of P resulted when SSP (7.10 kg ha-1) was applied. In acid soil, high fixation of P occurred when All -19 (12.64 kg ha-1), MAP (12.40 kg ha-1), SSP (12.22 kg ha-1), and DAP (11.74 kg ha-1) were applied. With all forms of phosphatic fertilizers fixation of added P occurred to the extent of 57.9 to 79.0 per cent in acid soil, 55.0 to 70.5 per cent in saline soil and 25.5 to 44.4 per cent in sodic soil. In saline soil availability of P might be higher for SSP and All-19 compared to ammonium/ potassium phosphate fertilizers. On the other hand, MPP, MAP and All-19 may be preferably applied in sodic/ acid soils alternative to SSP or DAP for realizing higher P release in soils from added fertilizers for the benefit of crop utilization.
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Nyamapfene, K. W. „Some relationships between topography and sodic soils in Zimbabwe“. Zeitschrift für Geomorphologie 30, Nr. 1 (09.04.1986): 47–52. http://dx.doi.org/10.1127/zfg/30/1986/47.
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Moritani, S., T. Yamamoto, H. Andry, M. Inoue, A. Yuya und T. Kaneuchi. „Effectiveness of artificial zeolite amendment in improving the physicochemical properties of saline-sodic soils characterised by different clay mineralogies“. Soil Research 48, Nr. 5 (2010): 470. http://dx.doi.org/10.1071/sr09158.
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The use of artificial zeolite (AZ) derived from recycled material as a soil amendment has recently received much attention. The effectiveness of AZ in controlling soil loss, sediment concentration, and runoff water quality in artificial sodic soils is discussed in this study. Soils containing 3 different types of clay mineralogies (kaolinitic, smectic, and allophanic) were tested. Aggregate fractions with sizes >2000 μm and saturated hydraulic conductivity were considerably decreased due to aggregate dispersion after soil sodification, although the sodic KS soil was most stable. The addition of 10% AZ to sodic soil improved the mean weight diameter (MWD) and saturated hydraulic conductivity due to a decrease in exchangeable sodium percentage, resulting in a reduction in soil aggregate dispersion. This improvement of sodic soil with AZ had a beneficial effect on erodibility (soil loss and runoff water). This is attributed to the increment in soil infiltration as a result of the suppression of seal formation on the soil surface. The suppression of erodibility effectively controlled the salt concentration of runoff water. A beneficial effect of MWD and AZ contents on sediment concentration was observed, and a negative influence of electrical conductivity. These findings complement the role of AZ in controlling soil erosion.
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Wang, Jinman, Zhongke Bai und Peiling Yang. „Simulation and Prediction of Ion Transport in the Reclamation of Sodic Soils with Gypsum Based on the Support Vector Machine“. Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/805342.
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The effect of gypsum on the physical and chemical characteristics of sodic soils is nonlinear and controlled by multiple factors. The support vector machine (SVM) is able to solve practical problems such as small samples, nonlinearity, high dimensions, and local minima points. This paper reports the use of the SVM regression method to predict changes in the chemical properties of sodic soils under different gypsum application rates in a soil column experiment and to evaluate the effect of gypsum reclamation on sodic soils. The research results show that (1) the SVM soil solute transport model using the Matlab toolbox represents the change in Ca2+and Na+in the soil solution and leachate well, with a high prediction accuracy. (2) Using the SVM model to predict the spatial and temporal variations in the soil solute content is feasible and does not require a specific mathematical model. The SVM model can take full advantage of the distribution characteristics of the training sample. (3) The workload of the soil solute transport prediction model based on the SVM is greatly reduced by not having to determine the hydrodynamic dispersion coefficient and retardation coefficient, and the model is thus highly practical.
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Vendan, R. Thamizh, und D. Balachandar. „Exploration of plant growth-promoting endophytic bacteria from the crops grown in sodic soils“. Bangladesh Journal of Botany 51, Nr. 2 (28.06.2022): 271–80. http://dx.doi.org/10.3329/bjb.v51i2.60424.
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Isolation of the potential endophytic bacteria from plants that are grown in sodic soils, their diversity and screening their plant growth-promoting activities for testing their efficiency as bio inoculants for the problem soils were studied. Twelve different isolates were selected out of 35 endophytic bacterial isolates on the basis of their richness in the endophytic population of different crop plants and the nucleotide sequences of 16S rRNA genes were observed. The endophytic bacteria for their plant growth-promoting traits such as nitrogen fixation, IAA production, ACC deaminase production, phosphate solubilization, siderophore secretion and antifungal activity were assessed. The best performing strains were evaluated using principal component analysis (PCA). The phylogenetic tree from the endophytic bacterial isolates of different crops grown in sodic soil was categorized into three clusters i.e. Firmicutes, β-Proteobacteria and γ- Proteobacteria. The PCA results identified two potential endophytic strains viz., Ma11 (Bacillus mojavensis) and Ri 2 (Pseudomonas fluorescens) from sodic soil-grown crops. The present findings revealed that the isolates, Ma 11 and Ri 2 were capable of improving crop growth under sodicity. These multifaceted endophytic bacterial isolates would be developed as new inoculants which will be highly suitable for sodic soils. Bangladesh J. Bot. 51(2): 271-280, 2022 (June)
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Jalali, Mohsen, Maryam Saeedi Lotf und Faranak Ranjbar. „Changes in some chemical properties of saline-sodic soils over time as affected by organic residues: An incubation study“. Polish Journal of Soil Science 53, Nr. 1 (22.06.2020): 1. http://dx.doi.org/10.17951/pjss.2020.53.1.1.
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<p>Salinization and sodification of agricultural lands in arid and semi-arid regions of the world are two limiting factors in the crop production. This study was conducted to evaluate the effect of readily available agricultural residues on changing some chemical properties of saline-sodic soils. Wheat, potato, sunflower, and canola residues were separately added into three saline-sodic soils at a rate of 2% by weight and thoroughly mixed with soils. Control and treated soils were incubated for 168 days at a constant moisture and temperature. The pH, electrical conductivity (EC), soluble cations, available nitrate (NO3-) and phosphorous (P), cation exchange capacity (CEC), and exchangeable sodium percentage (ESP) were measured during the incubation. The EC increased in the response to the incorporation of plant residues, whereas the pH was reduced. The application of organic components in soils increased CEC and decreased ESP. The results showed that the maximum reduction in ESP was observed in the potato treatment because of the highest Ca2+ concentration. The average reduction in ESP of treated soil samples at the end of incubation followed this order: 16.1% (potato residue-treated soil) >12.7% (canola residue-treated soil) >11.1% (wheat residue-treated soil) >9.6% (sunflwer residue-treated soil). The potato residue was the most effective amendment in changing the chemical properties of saline-sodic soils in comparison with other organic residues. The results indicated that the application of organic residues had a positive impact on reducing the soil sodicity and improving the soil fertility depending on their chemical composition.</p>
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Sanchez, Charles A., und Jeffrey C. Silvertooth. „Managing Saline and Sodic Soils for Producing Horticultural Crops“. HortTechnology 6, Nr. 2 (April 1996): 99–107. http://dx.doi.org/10.21273/horttech.6.2.99.
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About 33% of all irrigated lands worldwide are affected by varying degrees of salinity and sodicity. Soil with an electrical conductivity (EC) of the saturated extract >4 dS·m−1 is considered saline, but some horticultural crops are negatively affected if salt concentrations in the rooting zone exceed 2 dS·m−1. Salinity effects on plant growth are generally osmotic in nature, but specific toxicities and nutritional balances are known to occur. In addition to the direct toxic effects of Na salts, Na can negatively impact soil structure. Soil with exchangeable sodium percentages (ESPs) or saturated extract sodium absorption ratios (SARs) > 15 are considered sodic. Sodic soils tend to deflocculate, become impermeable to water and air, and puddle. Many horticultural crops are sensitive to the deterioration of soil physical properties associated with Na in soil and irrigation water. This review summarizes important considerations in managing saline and sodic soils for producing horticultural crops. Economically viable management practices may simply involve a minor, inexpensive modification of cultural practices under conditions of low to moderate salinity or a more costly reclamation under conditions of high Na.
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Ng, Loo Teck, und Jane Aiken. „Ameliorating Soil Sodicity Using Calcium Salt Incorporated Hydrogels“. Advanced Materials Research 93-94 (Januar 2010): 350–53. http://dx.doi.org/10.4028/www.scientific.net/amr.93-94.350.
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The potential of using hydrogels encapsulated with a water-soluble calcium salt, Ca(NO3)2 for the remediation and management of sodic soil, a degenerate soil condition associated with irrigation of recycled water was investigated. Environmentally friendly hydrogel, poly(2-hydroxyethyl methacrylate) (PHEMA) was synthesised from the monomer, 2-hydroxyethyl methacrylate (HEMA). HEMA was also used to copolymerise with another monomer, N-vinyl pyrrolidinone (NVP) to form a more hydrophlic hydrogel. Starch and glucose were incorporated in certain hydrogels with the intention of evaluating their biodegradability in soils since starch and glucose would serve as nutrients for microbials in soils. Delivery of calcium ions embedded in hydrogels were investigated on sodic and non-sodic clay loam under saturated condition. It was found that the optimum hydrogel for this application was the copolymer that contained HEMA and NVP in equal mole ratio.
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Sivapalan, S. „Effect of gypsum and polyacrylamides on water turbidity and infiltration in a sodic soil“. Soil Research 43, Nr. 6 (2005): 723. http://dx.doi.org/10.1071/sr04155.
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Water ponded on sodic soils can develop turbidity problems which seriously affect rice crop establishment. A total of 19 polyacrylamide products were assessed for their effectiveness to control water turbidity in a sodic soil under laboratory conditions. Anionic polyacrylamides were more effective than cationic or non-ionic polyacrylamides. When combined with gypsum, polyacrylamides were found to be more effective than when applied alone. A split application strategy was more efficient than continuous application of polyacrylamide treatments. Different rates of polyacrylamides at 2.5, 5, and 10 kg/ha did not show significant difference in controlling water turbidity. Selected polyacrylamides were also tested on soil columns to study their effect on infiltration and percolation of water through the soil. Results showed that polyacrylamides combined with low rates of gypsum did not modify the infiltration pattern to a greater extent. This study demonstrated that anionic polyacrylamides applied with small quantities of gypsum through a split application strategy would be an appropriate technique to overcome water turbidity problems in sodic soils.
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Oliveras-Berrocales, Miguel, Luis R. Pérez-Alegría und David Sotomayor-Ramírez. „Geostatistical analysis for mapping soil salinity in the Lajas Valley Agricultural Reserve, southwestern Puerto Rico“. Journal of Agriculture of the University of Puerto Rico 101, Nr. 1 (05.04.2021): 1–15. http://dx.doi.org/10.46429/jaupr.v101i1.14290.
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Studies were conducted in the 1950s to evaluate the degree and spatial extent of soil salinity and sodicity in the Lajas Valley in southwestern Puerto Rico. Problem areas were identified and most of these were remediated with the establishment of irrigation and drainage infrastructure, resulting in a four-fold increase in agricultural production over a 10-year period. The area is now an important agricultural region (known as the Lajas Valley Agricultural Reserve). But soil salinity and sodicity are important concerns among farmers. In this paper we used published data and re-created the spatial distribution of soil salinity and sodicity using geostatistical analysis with Geographic Information Systems (GIS). An Ordinary Kriging method was applied to map the spatial distribution of soil salinity and to classify soils in four classes: (i) Normal, (ii) Saline, (iii) Saline-Sodic, and (iv) Sodic. The original hand-drawn maps were digitized using the Georeferencing Tool in ArcGIS, guided by a recent aerial photo of the Lajas Valley. Salinity and sodicity isopleths were created using Surface Generation to map the spatial distribution and to compare the newly created data to the original maps. The relative error in aerial estimate between the old and new maps for Normal, Saline, Saline-Sodic, and Sodic surface soils was between 1 and 5 percent. The new maps developed with geostatistical analysis can predict soil problem areas with a 94% coincidence compared with the hand-drawn maps. The highest proportion of soils classified as Normal was found in the upper soil layers and the proportion of soils affected by salt and sodium increased with depth. The combination of geostatistical analysis and GIS is a cost-effective and trustworthy method for analyzing similar datasets that would otherwise be costly and involve lengthy time commitments.
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Marino, Giulia, Daniele Zaccaria, Richard L. Snyder, Octavio Lagos, Bruce D. Lampinen, Louise Ferguson, Stephen R. Grattan et al. „Actual Evapotranspiration and Tree Performance of Mature Micro-Irrigated Pistachio Orchards Grown on Saline-Sodic Soils in the San Joaquin Valley of California“. Agriculture 9, Nr. 4 (12.04.2019): 76. http://dx.doi.org/10.3390/agriculture9040076.
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In California, a significant percentage of the pistachio acreage is in the San Joaquin Valley on saline and saline-sodic soils. However, irrigation management practices in commercial pistachio production are based on water-use information developed nearly two decades ago from experiments conducted in non-saline orchards sprinkler-irrigated with good quality water. No information is currently available that quantify the effect of salinity or combined salinity and sodicity on water use of micro-irrigated pistachio orchards, even though such information would help growers schedule irrigations and control soil salinity through leaching. To fill this gap, a field research study was conducted in 2016 and 2017 to measure the actual evapotranspiration (ETa) from commercial pistachio orchards grown on non-saline and saline-sodic soils in the southern portion of the San Joaquin Valley of California. The study aimed at investigating the functional relations between soil salinity/sodicity and tree performance, and understanding the mechanisms regulating water-use reduction under saline and saline-sodic conditions. Pistachio ETa was measured with the residual of energy balance method using a combination of surface renewal and eddy covariance equipment. Saline and saline-sodic conditions in the soil adversely affected tree performance with different intensity. The analysis of field data showed that ETa, light interception by the tree canopy, and nut yield were highly and linearly related (r2 > 0.9). Moving from non-saline to saline and saline-sodic conditions, the canopy light interception decreased from 75% (non-saline) to around 50% (saline) and 30% (saline-sodic), and ETa decreased by 32% to 46% relative to the non-saline orchard. In saline-sodic soils, the nut yield resulted around 50% lower than that of non-saline orchard. A statistical analysis performed on the correlations between soil physical-chemical parameters and selected tree performance indicators (ETa, light interception, and nut yield) revealed that the sodium adsorption ratio (SAR) adversely affected tree performance more than the soil electrical conductivity (ECe). Results suggest that secondary effects of sodicity (i.e., degradation of soil structure, possibly leading to poor soil aeration and root hypoxia) might have had a stronger impact on pistachio performance than did salinity in the long term. The information presented in this paper can help pistachio growers and farm managers better tailor irrigation water allocation and management to site-specific orchard conditions (e.g., canopy features and soil-water salinity/sodicity), and potentially lead to water and energy savings through improved irrigation management practices.
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Naidu, R., RH Merry, GJ Churchman, MJ Wright, RS Murray, RW Fitzpatrick und BA Zarcinas. „Sodicity in South Australia - a review“. Soil Research 31, Nr. 6 (1993): 911. http://dx.doi.org/10.1071/sr9930911.
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The current knowledge of the nature and distribution of sodic soils in South Australia is reviewed. The agriculturally developed area of South Australia lies south of latitude 32-degrees-S. and is mainly used for low intensity grazing and dry land cereal/sheep production. A high proportion of the State, including much of the high rainfall area, has soils which are sodic (>6% ESP) through a significant proportion of the profile but information on the precise nature of sodicity in these soils is limited. Where exchangeable cation data axe available, the analytical techniques used often did not precisely delineate between soluble salts in the soil and ions on exchange sites. Therefore, many of the datasets have major weaknesses and may be unreliable. Since many soils with ESP <6 also show dispersive characteristics typical of sodic soils, there is an urgent need for new sodicity studies relating to distribution and the criteria (ESP) used to identify dispersive soils. Information on the effect of sodicity on nutrient requirements of plants, especially the modern varieties, is scarce both locally and internationally, making development of management strategies for economically sustainable crop production difficult. Further, many different grades of gypsum are available in South Australia. Preliminary studies show the presence of impurities drastically influences gypsum dissolution characteristics. More effort is needed to assess the quality and reactivity of South Australian gypsum. Some effort has been directed by land managers towards reclamation and management of sodic soils by using both gypsum and lime either separately or as mixtures. However, there is neither a scientific basis for the application of gypsum-lime mixtures nor crop production data to support such management strategies.
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Du, Xuejun. „Fermenting straw reduced salt damage and improved the stability of the bacterial community in a saline–sodic soil“. Journal of Agricultural Science and Agrotechnolog 1, Nr. 1 (10.05.2022): 1–18. http://dx.doi.org/10.56391/jasa.2022.1005.
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This study aimed to explore the potential of fermenting straw return for remediation of soil salinity. A sealed–pot experiment was used to evaluate four treatments: CK (0 g fermenting rice straw), T1 (120 g fermenting rice straw), T2 (240 g fermenting rice straw), and T3 (360 g fermenting rice straw). Using 13C isotope tracer technique and molecular biological techniques to detect the physical, chemical, and biological properties of saline–sodic soils. The results showed that a small amount of CO2 was produced upon addition of soda–alkali soil to the soil after straw was applied. Quantitative analysis showed that the proportion of CO32– reduction of total CO32– was peaked (4.90%) in treatment T3. Concomitantly, under this treatment soil pH, SAR and ESP were reduced, whereas soil porosity and K+, Ca2+, and Mg2+ concentrations, and total nitrogen (TN), SOM, and MBC were increased. PCoA analysis showed that the addition of straw significantly changed the community structure of bacteria in a saline–sodic soil, and increased the Chao1 and Shannon indexes. Straw application increased ryegrass shoot and root biomass without allelopathic effects in the saline–sodic soil used. Our results highlighted that rice straw should be collected and artificially decomposed after rice harvest and then applied for the reclamation of strongly saline–sodic soils in the Songnen Plain and other similar areas.