Zonal,provincial, lithological,and geomorphic features of soil salinization in the Southern federal okrug of Russia

The relationships between soil salinization and the zonal and provincial bioclimatic conditions, the lithological composition of the sediments, and the geomorphic features of the territory have been analyzed for the Southern federal okrug of Russia. It is shown that the lithological and geomorphic conditions (relief, salinity of parent materials, degree of drainage, and the depth of saline groundwater) play an important role in the distribution of salt-affected soils against the background of the more general regularities specified by the climate. The participation of salt-affected soils in the soil cover of the Southern federal okrug increases in the eastward direction from the forest-steppe zone to the semidesert zone in agreement with an increase in the aridity and continentality of the climate. The chemical composition of soil salts also changes: the sulfate and soda-sulfate types predominate in the forest-steppe zone; the sulfate type or the sulfate type with the participation of soda, in the steppe zone; the sulfate-chloride type, in the dry steppe zone; and the chloride type, in the semidesert zone. The lithological and geomorphic conditions within the particular zones and provinces affect the distribution pattern of the salt-affected soils and the degree and chemistry of the soil salinization. The areas of salt-affected soils were calculated with the use of a digital version of the Map of Salt-Affected Soils of Russia (1: 2.5 M scale) with due account for the participation of these soils in the soil cover of the particular delineations and the data on the depth of the upper boundary of the salt-bearing horizons, the degree and chemistry of the soil salinization, and the area of solonetzes and solonetzic soils.     

Quantification of the areas of saline and solonetzic soils in the Ural Federal Region of the Russian federation

Soil Salinization Map of Russia on a scale of 1: 2500000 (the paper version) has been used for compiling an electronic map of the Ural Federal Region and an attribute database containing twelve characteristics of soil salinization. The areas of saline soils have been quantified for the entire region and its administrative districts. The total area of saline soils in the 0- to 200-cm layer averages up to 6.85 million ha or 5.53% of the plains in the region. The area of soilssaline in the 0- to 100-cm layer averages up to 4.91 million ha, including 4.13 million ha of weakly solonchakous soils (84%) and 0.78 million ha of solonchakous ones (16%). More than half of them (58.3%) are assigned to the moderately and strongly saline soils. The soils saline in the 0- to 100-cm layer are characterized by the neutral salinization type (45%) or the types of soda salinization and neutral salinization with soda (55%). The areas of the region with saline soils are dominated by solonetzic microassociations. The average area of the solonetzes is about 3 million ha. The area of solonchaks is about 0.09 million ha. The area of saline soils is the greatest in Kurgan oblast and the lowest in Sverdlovsk oblast and the Yamal-Nenets autonomous okrug. The formation of saline soils in the Ural Federal Region is related to the climatic conditions of the steppe zone with insufficient moistening and lithologicgeomorphologic conditions (saline Paleogene-Neogene deposits and poor drainage of the area).     

Anthropogenic transformation of soils in the northern Ergeni Upland (studies at the first experimental plot of the Arshan’-Zelmen Research Station)

The results of soil studies performed in 2005–2009 at the first experimental plot of the Arshan’-Zelmen Research Station of the Institute of Forest Science of the Russian Academy of Sciences are discussed. The post-reclamation state (about 55 years after reclamation) of the soils under forest shelterbelts and adjacent croplands in the rainfed agriculture was studied. The long-term efficiency of forest reclamation and crop-growing technologies developed in the 1950s by the Dokuchaev Soil Science Institute and the Institute of Forest to reclaim strongly saline solonetzic soils was proved. In 55 years, strongly saline sodic solonetzes with sulfate-chloride and chloride-sulfate composition of salts were replaced by agrogenic soils with new properties. Under forest shelterbelts, where deep (40–60 cm) plowing was performed, the soils were transformed into slightly saline solonetzic agrozems with slight soda salinization in the upper meter and with dealkalized plowed and turbated horizons (0–20(40) cm). Under the adjacent cropland subjected to the influence of the shelterbelts on the soil water regime, strongly saline solonetzes were transformed into solonchakous agrosolonetzes with slight soda salinization in the upper 50 cm. In the plow layer, the content of exchangeable sodium decreased to 4–12% of the sum of exchangeable cations. An increased alkalinity and the presence of soda were found in the middle-profile horizons of the anthropogenically transformed soils.     

Saline-alkali soils of Russia

Diagnostics, methods of evaluation, and geography of saline-alkali (soda) soils are discussed. The saline-alkali soils include soils of different genetic types with the following chemical properties: the pH of the water suspensions equal to or higher than 8.5; the total alkalinity exceeding 1.4 meq/100 g of soil and the sum of water-soluble calcium and magnesium; and the presence of soluble “alkaline” salts in the soil profiles, the hydrolysis of which results in the alkaline reaction of the soils. The chemical properties of the saline-alkali soils are largely related to the presence of soda (Na₂CO₃, NaHCO₃) in the soils. According to their morphological properties, saline-alkali soils are divided into two groups: alkaline soils with an undiferentiated profile and without a morphologically pronounced solonetzic (natric) horizon, and alkaline soils with a pronounced natric horizon (solonetzes). Solonetzes, in turn, are divided into (a) alkaline solonetzes (with soda or with soda and neutral salts), (b) solonetzes salinized with neutral salts (saline soils) with increased alkalinity in the solonetzic and lower lying horizons, (c) saline solonetzes throughout the profile, and (d) leached solonetzes containing no soluble salts in the profile and almost no exchangeable sodium in the soil exchange complex (SEC) (“dead” solonetzes). The latter two groups of solonetzes cannot be ranked among the alkaline soils. The alkalinity of the saline-alkali soils under study is due to carbonate and bicarbonate ions (carbonate alkalinity), organic acid anions (organic alkalinity), and borate ions (borate alkalinity). The carbonate alkalinity is due to both soda (Na₂CO₃, NaHCO₃) and CaCO₃.     

Early stages of pedogenesis at the bottom of a 30-year-old artificial depression under semidesert conditions

Initial soils that developed at the bottom of an artificial hollow 30 × 40 m in size and 3 m in depth have been studied. The hollow was dug on a plot with a predominance of solonetzic complexes in the soil cover on the territory of the Dzhanybek Research Station in 1979. A soil with a shallow but clearly differentiated profile composed of a litter, a humus-accumulative W horizon leached from carbonates, and an underlying C1ca horizon with a high content of dispersed carbonates formed in the hollow over 30 years. The total thickness of these horizons is 7–10 cm. The morphology of the profile corresponds to the slightly alkaline humus-accumulative calcareous soil type of the order of immature soils in the current classification of Russian soils. The soil-sediment layer to a depth of >80 cm contains little soluble salts, predominantly sulfates; the content of exchangeable Na does not exceed 1 meq/100 g. Groundwater of calcium sulfate composition occurs at a depth of ～3.8 m. These features, together with additional moistening by low-saline melt water, ensure favorable conditions for the spontaneous propagation and development of herbaceous, shrubby, and woody plants in the bottoms of artificial hollows. The development of a soil profile is accompanied by the depletion of the clay fraction from the upper W horizon, presumably due to the predominant removal of smectite minerals. In the upper W horizon, transformations of layered aluminosilicates takes place: it involves the formation of illites from smectites and from smectitic layers in illite-smectite mixed-layered minerals and partial vermiculitization of chlorites. The technology used upon the excavation of the hollow can be recommended for growing woody-shrubby plants on soils of the solonetzic complex in the clay semidesert during a relatively short time period.     

The effect of the microrelief on salinization of semidesert soils

The microrelief affects the distribution of soluble salts in the upper horizons of salt-affected soils. This has been shown for semidesert soils—meadow solonchak, solonchakous meadow, and meadow soils—within the Sulak Lowland in the Republic of Dagestan. The total content of salts and the concentrations of sodium, magnesium, chlorine, and sulfate ions are higher in the soils of microelevations. However, no significant effect of the microrelief on the distribution of calcium in the soil water extracts has been found. The properties of the solid soil phase (the humus content and the content of adsorbed bases, including calcium, magnesium, and sodium) and the soil pH are not reliably differentiated by the elements of the local microtopography.     

Alkalinity of virgin solonetzes in northern Kalmykia (the Arshan-Zel’men Experimental Station)

The alkalinity of virgin solonetzes of the Ergeni Upland, Ergeni Plain, and Sarpinsk Lowland has been studied. These soils are characterized by the neutral salinization and the high alkalinity of the solonetzic and subsolonetzic horizons. The analysis of the soil water extracts demonstrated that the highest alkalinity is typical of the subsolonetzic horizons containing calcium carbonates (the B2 and BCca horizons). In the solonetzic horizons without CaCO₃, the alkalinity is lower despite the high exchangeable sodium percentage (up to 42%). The alkalinity of the solonetzic and subsolonetzic horizons may be conditioned by two processes: (a) the hydrolysis of the exchange complex (EC) containing sodium (EC-Na + H₂O ↔ EC-H + Na⁺ + OH⁻) and (b) the reaction of the ion exchange with the substitution of calcium for sodium in the exchange complex (EC-2Na + CaCO₃ ↔ EC-Ca + 2Na⁺ + CO₃²⁻). Calculations performed on the basis of the thermodynamic equations of the physicochemical equilibria according to the LIBRA program indicate that soda is absent in the solonetzic horizons, whose alkalinity is related to the carbonatecalcium equilibria. The high alkalinity of the calcareous subsolonetzic horizons is related to the presence of soda in combination with CaCO₃. The formation of soda in these horizons is due to the reaction of ion exchange described by Gedroits.     

Changes in the salinity of solonetzic soil complexes of the Ergeni Upland under long-term anthropogenic impact (soil studies at the Arshan’-Zel’men Experimental Station of the Russian Academy of Sciences)

Unique experiments performed since the 1950s at the Arshan’-Zel’men Experimental Station have formed the basis for afforestation in the dry steppe and semidesert zone without irrigation on the salt-affected soils of solonetzic soil complexes of the Ergeni Upland. Ameliorative measures favored the accumulation of productive moisture in the upper 2-m-thick soil layer, which ensured the growth of trees and the partial leaching of soluble salts to a depth of 1–1.4 m. However, no complete desalinization of the soil profiles took place. The degree of removal of exchangeable sodium from the exchange complex (soil dealkalization) was smaller. The monitoring of changes in the salt status of the soils upon agroforest reclamation was performed until the early 1980s. Our investigations of 2005–2006 showed that the soil amelioration is still in progress: the salt maximum in the profile of the solonetzes descended to a depth of 2.2 m, and the exchangeable sodium was lost from the plow layer (0–40 cm). Plowed soils between forest shelterbelts were also subjected to desalinization and dealkalization of their soil profile, though less intensely than those under the shelterbelts.     

Modern state of soil salinity in solonetzic soil complexes at the Dzhanybek Research Station in the North Caspian Region

Variations in the salinity of virgin soils of solonetzic soil complexes at the Dzhanybek Research Station are characterized on the basis of field materials obtained by the author in 2002–2004. The soil salinity is characterized with respect to the depth of the upper boundary of salt-bearing horizons, the total amount of salts, the content of toxic salts, and the chemical composition of salts. Changes in the soil salinity under dry farming conditions are estimated for the following soil management practices: (1) agroforest amelioration with additional moistening of virgin soils owing to snow retention by the adjacent shelterbelts and forest plantations, (2) intense grazing, (3) soil fallowing after normal tillage to a depth of 20–25 cm, and (4) soil fallowing after deep tillage to a depth of 40–50 cm. It is shown that normal tillage and considerable grazing pressure do not affect the salinity of the studied soils. No definite effect of the shelterbelts on the salt status of the adjacent virgin soils of the solonetzic complex has been revealed. Deep soil tillage strongly affects the salt status of solonetzes: the content of toxic salts in the upper meter considerably decreases. Virgin solonetzes are usually moderately or strongly saline soils, whereas deeply tilled solonetzes are slightly or moderately saline soils.     

Alkalization of irrigated soils suitable for orchard growing in steppe Crimea and prospects for their use

Data of large-scale soil surveys performed by the Ukrgiprosad Institute (Ukrainian Institute for Orchard Growing) in 1997–2013 on irrigated soils of steppe Crimea reserved for orchards on the area of about 3000 ha are discussed. It is shown that all the studied soils are subjected to alkalization with the presence of soda and with an increase in concentrations of sodium and magnesium bicarbonates up to the values toxic for fruit crops. The concentrations and occurrence frequencies of alkaline salts depend on the soil type, the presence of solonetzic features, the amount of carbonates, the particular depth in the soil profile, the subsoiling, and other factors. Within the studied area, some soils are unsuitable or partly suitable for orchard growing. To improve the soil conditions for orchard growing in the areas subjected to alkalization, alkaline salts should be neutralized to nontoxic level, and the soil alkalinity should be reduced using chemical reclamation methods.     

Soil Cover of the Svetloyarsk Irrigation System after 50 Years of Reclamation Practices

The state of irrigated soils of the Svetloyarsk irrigation system (Volgograd oblast) after 50 years or irrigation and ameliorative impacts has been assessed with the use of published and new field data, cadastral materials, and remote sensing materials. In the recent two decades, the area of regular irrigation and the volume of irrigation water have decreased, which has led to the lowering of the groundwater level to the depth of 5 m and more. The pattern of sown areas is characterized by a rise in the portion of winter cereals. Surface planing during the construction of the irrigation system led to a considerable transformation of the soil cover. On convex elements, solonetzic and other topsoil horizons were almost completely cut off. In many areas, they were replaced by a mixture of different horizons, including carbonaceous material. There are now significant areas of soils of different geneses with carbonates from the surface. Former solonchakous and slightly solonchakous soils are now at the stage of deep desalinization: soluble salts in them have been washed to the second meter, where slightly or moderately saline horizons with a predominance of sulfates have been formed. Irrigated areas on satellite images are specified by spotty patterns differing from those of natural solonetzic soil complexes because of the significant transformation of the soil cover during the construction and operation of irrigation system. The anthropogenically transformed soils can be mapped. Soil maps reflecting the modern state of the of soil cover of irrigated areas are given.     

Soil carbon dynamics in saline and sodic soils: a review

Soil salinity (high levels of water-soluble salt) and sodicity (high levels of exchangeable sodium), called collectively salt-affected soils, affect approximately 932 million ha of land globally. Saline and sodic landscapes are subjected to modified hydrologic processes which can impact upon soil chemistry, carbon and nutrient cycling, and organic matter decomposition. The soil organic carbon (SOC) pool is the largest terrestrial carbon pool, with the level of SOC an important measure of a soil's health. Because the SOC pool is dependent on inputs from vegetation, the effects of salinity and sodicity on plant health adversely impacts upon SOC stocks in salt-affected areas, generally leading to less SOC. Saline and sodic soils are subjected to a number of opposing processes which affect the soil microbial biomass and microbial activity, changing CO₂ fluxes and the nature and delivery of nutrients to vegetation. Sodic soils compound SOC loss by increasing dispersion of aggregates, which increases SOC mineralisation, and increasing bulk density which restricts access to substrate for mineralisation. Saline conditions can increase the decomposability of soil organic matter but also restrict access to substrates due to flocculation of aggregates as a result of high concentrations of soluble salts. Saline and sodic soils usually contain carbonates, which complicates the carbon (C) dynamics. This paper reviews soil processes that commonly occur in saline and sodic soils, and their effect on C stocks and fluxes to identify the key issues involved in the decomposition of soil organic matter and soil aggregation processes which need to be addressed to fully understand C dynamics in salt-affected soils.     

Salt-affected soils of the Barguzin Depression

Factual materials on salt-affected soils in the Barguzin Depression (Buryat Republic) are generalized. A geomorphic map of the depression has been developed. The distribution of salt-affected soils and the specificity of salinization in different geomorphic regions are characterized. These soils tend to be developed within the low lacustrine–alluvial plain of the depression, on the floodplain of the Barguzin River and its tributaries. Smaller areas of salt-affected soils are found on the river terraces. They are virtually absent on ancient sandy ridged terraces (kuituns). The genesis and chemistry of soil salinization are mainly related to the discharge of slightly saline deep water along tectonic faults and fissures. An additional source of soil salinity is represented by surface water flows. The presence of permafrost preventing the leaching of salts and the cryoarid climate favoring the migration of salts toward the soil surface during the dry spring and early summer periods and during the soil freezing in the winter contribute to the soil salinization. Slightly saline hydromorphic solonchakous soils predominate among salt-affected soils of the depression; the portion of semihydromorphic saline soils is smaller. Automorphic saline soils rarely occur in the depression. Strongly saline soils— solonchaks—are widespread within lacustrine depressions around salt lakes. Soils of the soda and sulfate salinization predominate. The content of chlorides is small; their increased amounts, as well as the presence of sulfates, are indicative of the discharge of dee ground water onto the surface. The soda type of salinization is also related to the discharge of deep stratal water with further transformation of salt solutions during freeze–thaw cycles. Under anaerobic conditions, the formation of soda is favored the processes of sulfate reduction.     

Changes in the soils of solonetzic associations in 30 years after their reclamation with the use of moldboard plowing,deep tillage with a three-tier plow,and deep rotary tillage

Changes in the properties of solonetzic soil associations (chestnut solonetzic soils and chestnut solonetzes) in the dry steppe after their reclamation have been studied for 30 years. The reclamation included the deep three-tier plowing and the approach of rotary tillage. A single rotary tillage operation resulted in the formation of fine aggregates of equal sizes in the plow layer; any morphological features of the restoration of solonetzic pedogenesis are absent. The atmospheric moisture easily penetrates into the soil, and soluble salts are leached off to a great depth. In 30 years since the soil amelioration with the use of a PMS-70 rotary tiller, the humus content has increased up to 3.3% in the upper 20-cm-thick layer and up to 2.4% in the layer of 20–40 cm. The content of adsorbed Na⁺ in the 20- to 30-cm-thick layer has decreased to 10.6% of the cation exchange capacity (in comparison with 19.8% in the nonreclaimed soil). The spatial heterogeneity of the soil cover has decreased in comparison with that prior to the reclamation. During the entire observation period, crop yields gained from the fields reclaimed with the use of the rotary tiller have been by 25–60% higher in comparison with those on the fields with traditional treatments.     

Mathematical simulation of water and salt transfer in geosystems of solonetzic soils in the Northern Caspian region

The Dzhanybek two-dimensional radial-axial mathematical model was developed for water and salt transfer in geosystems of solonetzic complexes of the Northern Caspian region; the model is capable of considering the geochemical links and revealing the features of migration processes between the conjugated elements of the microcatena. The simulation results suggested that the stabilization of salinization-desalinization processes occurs under stable weather conditions within approximately 100 years. When the weather conditions changed (the total moisture pool of the area increased from 1978), the simulation results indicated a tendency toward salinization of dark-colored soils in microdepressions and removal of salts in the upper 1-m thick soil layer on microhighs and microslopes. Predictions for 2040 showed that a deep accumulation of salts in microdepressions and desalinization of soils of microhighs and microslopes will occur under the current weather conditions. Thus, the changes in the halogeochemical capacity of geosystems of solonetzic complexes primarily depend on the climatic conditions, although the capacity value remains almost constant with increasing total water reserves; the changes occur only between the conjugated soils of solonetzic complexes, which is of great importance for predicting the soil-geochemical status of the entire landscape.     

Properties of solonetzes on terraces of salt lakes Bulukhta and Khaki in the Caspian Lowland

A comparative assessment of pedogenetic processes in solonetzes (Calcic Gypsic Salic Solonetzes (Siltic, Albic, Cutanic, Differentic)) developing on terraces of lake depressions within the Volga–Ural interfluve of the Caspian Lowland has been performed on the basis of data on their macro- and micromorphological features and chemical, physicochemical, and physical properties. The studied soils have number of common characteristics shaped by the humus-accumulative, solonetzic, eluvial–illuvial, calcification, and gypsification processes. However, it is shown that macro- and micromorphological indicators of solonetzic processes (the development of clay–humus coatings and the character of structural units in the solonetzic (B) horizon) do not always agree with the modern physicochemical conditions of the development of this process. This is explained by differences in the degree and chemistry of the soil salinization and the depth and salinity of the groundwater. Solonetzes developing on the second terrace of Playa Khaki are distinguished by the highest water content and maximum thickness of the horizons depleted of soluble salts. They are characterized by the well-pronounced humus-accumulative process leading to the development of the light-humus (AJ) horizon. In other solonetzes, the accumulation of humus is weaker, and their topsoil part can be diagnosed as the solonetzic-eluvial (SEL) horizon. Active solodic process and illuviation of organomineral substances with the development of thick coatings and infillings in the B horizon are also typical of solonetzes on the second terrace of Playa Khaki. Micromorphological data indicate that, at present, layered clayey coatings in these soils are subjected to destruction and in situ humification owing to the active penetration of plant roots into the coatings with their further biogenic processing by the soil microfauna. The process of gleyzation (as judged from the number of Fe–Mn concentrations) is most active in solonetzes developing on the first terrace of Playa Khaki. These soils are also characterized by the highest degree of salinization with participation of toxic salts. The maximum accumulation of gypsum is typical of the heavy-textured horizons.     

Factors and mechanisms of soil salinization under vineyards of southern Taman

The spatial distribution of saline soils under vineyards in the south of Taman Peninsular is discussed. The Paleogene–Neogene clays of the Komendantskaya Mount serve as the source of salts. Vineyards were planted on an inclined plain at the foot of this mount. At present, their state on salt-affected soils worsens. In the upper part of the plain, solonchakous or deep-solonchakous slightly saline and nonsaline (within the upper 2 m) dark quasigley vertic soils (Vertisols) are formed. The salts are of the sulfate–sodium composition. Their vertical distribution has an eluvial pattern with a quick rise in the salt content from the surface layer to the depth of 50–100 cm and with a gradual increase in the salt content in the deeper layers. The absence of chlorides in the soils of flat areas within the slope attests to the predominance of lateral leaching of salts down the slope over their vertical leaching in the soil profiles. In the lower part of the slope, soil salinization mainly takes place in the hollow crossing the plain and the vineyard from the north to the south. In the middle part of the slope, nonsaline (to a depth of 2 m) agrohumus quasigley soils (Haplic Chernozems (Clayic, Aric, Stagnic)) are formed. Slight chloride–sulfate sodium salinization is only seen in the soils of the hollow, which contain fine-crystalline gypsum in the solid phase and display the accumulation of sodium chlorides in the middle part of the soil profile (in the 60–150-cm-thick layer). Heavy loamy agrochernozems with migrational and segregational forms of carbonates (Haplic Chernozems (Loamic, Aric, Pachic) are developed in the lower part of the slope; they are nonsaline to the depth of 2.5 m. In the area of transition from the humusquasigley soils to chernozems, specific horizons are formed in the hollow at the depth of more than 250 cm. Their soil solutions contain sodium, calcium, and magnesium chlorides against the background of the presence of fine-crystalline gypsum in the solid phase, which is typical of secondary salinization.     

Climate and soil salinity in the deserts of Central Asia

A comparative analysis of climatic and soil salinity characteristics of the deserts of Central Asia, including deserts of the Turan Depression, the Gobi Desert, and deserts of the Dzungar and Tarim depressions was performed. The climatic characteristics—the degree of aridity, the degree of continentality, and the amount and regime of precipitation—are different in these deserts. No direct relationships between the areas occupied by the automorphic salt-affected soils and the aridity of the climate are observed in the studied regions. In the automorphic landscapes of Asian deserts, the degree and chemistry of the soil salinization and the distribution of salt-affected soils are controlled by the history of the particular territories rather than by their modern climatic conditions. The presence and properties of the salt-bearing rocks and the eolian migration of salts play the most significant role. The deficit of moisture in the modern climate favors the preservation of salt accumulations in places of their origin. The specific features of the climate, including the regime of precipitation, affect the redistribution of salts in the profiles of automorphic salt-affected soils. An increase in the degree of climatic continentality is accompanied by the decrease in the intensity of weathering and initial accumulation of salts. A different situation is observed in the soils of hydromorphic desert landscapes, in which the degree of salinity of the surface horizons and the area occupied by salt-affected soils are directly influenced by the modern climatic conditions.     

Diagnosis of solonetzic process in virgin and agrogenically transformed soils of different regions

To diagnose solonetzic process in virgin and agrogenically transformed soils of solonetzic soil complexes in the chernozemic and chestnut soil zones of European Russia and Western Siberia, their swelling kinetics and physicochemical characteristics were been studied. It was shown that a simultaneous application of these two approaches is more efficient than their separate use. The degree of manifestation of solonetzic process in the studied soils was determined. Swelling curves of sodic reclaimed solonetzes of Lyubinsk district of Omsk oblast and of a virgin solonetz of the Baraba Lowland with a moderate content of adsorbed sodium proved to be similar to those described for the vertic soils with a low infiltration capacity in the North Caucasus.     

洼涝盐渍土“淡化肥沃层”的培育与功能的研究

本文通过１９８６－１９９３年微区及大田试验说明,对洼涝盐渍土采用不同培肥措施,培育“淡化肥沃层”,改善了土壤理化生物状况,提高了土壤肥力。因此,在不减少土体盐贮量的条件下,以“肥”调控水盐,把盐分调节在土壤表层４０ｃｍ根系活动层以下,在作物主要根系活动层创造一个良好的肥水盐生态环境,以利实现高产。