Genesis, hydrology, and properties of soils in mesodepressions waterlogged by surface water in the northern Ryazan forest-steppe

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ISSN 1064-2293, Eurasian Soil Science, 2007, Vol. 40, No. 9, pp. 917–927. © Pleiades Publishing, Ltd., 2007.Original Russian Text © F.R. Zaidel’man, A.P. Shvarov, T.M. Ginzburg, 2007, published in Pochvovedenie, 2007, No. 9, pp. 1029–1040.

INTRODUCTION

About a century ago, Dokuchaev [5], Kossovich[16], Tumin [17], and other pioneers of genetic soil sci-ence showed that there are excessively moist soils withsigns of hydromorphism and podzolization among theautomorphic chernozems of the forest-steppe. In thelast ten years, some authors studied these soils in flat-bottom steppe depressions predominantly in the terri-tory of the Tambov Lowland and the Central RussianUpland. Akhtyrtsev [1] found that “soils of flat-bottomdepressions develop under the influence of the surfacegley–eluvial process without solodization” (P. 14). Heconcluded that, in such depressions of Tambov oblast,soils with pronounced whitish horizons were formedwith their genesis not being associated with solodiza-tion and podzolization. Their origin, in the authors'opinion, is related to two processes: movement of siltand differentiation of the soil profile, as well as tempo-rary surface gley. “The combination of these processesleads to the formation of gray forest pseudopodzolic(surface gley–eluvial) soils” (P. 15).

The pattern of the soil cover of the Tambov Lowlandwas studied in detail by Denisova and Lebedeva [4]using the example of soils in a typical catena of depres-sions and typical chernozems as automorphic soils.These authors concluded that light-colored soils ofdepressions develop due to the transformation of thebackground chernozems under the influence of “addi-tional surface moistening.” Denisova and Lebedeva

found that “the morphological changes were displayedin a decrease in the thickness of the humus layer at aconstant humus content in the upper horizons.” Theyshowed that soils of depressions with the light-coloredeluvial horizons had a residual dark humus horizon; thebleached layers contained concretions and the texturalones have humus cutans and gley features.

The aim of our studies was to reveal the soil-form-ing conditions for the gleyed soils with light-coloredacid eluvial horizons and their properties confined tothe depressions of the forest-steppe in Ryazan oblast.These soils occur among leached chernozems spread inthe northernmost parts of the chernozems' area. Thetasks to study the properties of these soils and theregimes, diagnostic, and agroecological features wereset. These mineral hydromorphic soils with well-expressed light-colored eluvial horizons are restrictedto rather flat areas, more frequently, to low sites andoval depressions formed by cryogenic and some otherphenomena. The specific features of the relief deter-mines the redistribution of the surface runoff in theperiod of snow melting or storm rainfalls; the long-termstagnation of water in depressions; and the excessivemoistening, sharp lowering of the redox potential, andanaerobiosis. Precisely such conditions appear inthese situations that are favorable for the intensivedepletion of iron in the mineral part of soils, that is,for gleyzation [6–9].

GENESIS AND GEOGRAPHY OF SOILS

Genesis, Hydrology, and Properties of Soils in Mesodepressions Waterlogged by Surface Water

in the Northern Ryazan Forest-Steppe

F. R. Zaidel’man, A. P. Shvarov, and T. M. Ginzburg

Faculty of Soil Science, Moscow State University, Leninskie gory, Moscow, 119992 Russia

Received June 19, 2006

Abstract

—On the interfluves and in small depressions of the Ryazan forest-steppe, under periodic stagnationof surface water, acid chernozem-like soils with a relatively thick humus horizon, podzolic horizons, and mar-ble-colored gleyed B1 and B2 horizons are formed. The eluvial horizons of these soils contain Mn–Fe nodules,and dark humus coatings occur in the illuvial horizons. In the spring, the eluvial horizons of these soils areexcessively moistened and gravitational water stagnates on the soil surface for 3–4 weeks. The formation of theacid light-colored eluvial horizons of the soils on leached rocks is related to gleying under the conditions of thestagnant–percolative regime. Their total thickness is 15–25 cm and more. According to the properties of theirsolid phase, these horizons are similar to the podzolic horizons of soddy-podzolic gleyed soils. These soils havenot been represented in the classification systems of soils of the USSR and Russia. Based on the principles of thesubstantial–genetic classification, one of the authors of this article [9] referred this soil to gleyed podzolic cher-nozem-like soils, thus, considering it as an individual genetic soil type. The gleyed podzolic chernozem-like soilsdiffer from the leached chernozems by their low productivity and difficulty of tillage. In humid and moderatelymoist years, the death of crops or a reduction in yield are probable because of the excess of moisture.

DOI:

10.1134/S1064229307090013

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OBJECTS AND METHODS

Automorphic and hydromorphic soils of the secondfloodplain terrace of the Oka River in the territory of theRyazan Soil–Hydrological Station (Department of SoilPhysics and Amelioration, Faculty of Soil Science,Moscow State University) were the objects for thestudy. These soils develop on the flat plain with smallelevations and shallow oval depressions. The soil-form-ing rocks are loess-like calcareous loamy clay underlainby well permeable alluvial sands at a depth of 3–4 m.The river drains the groundwater in the sands. There-fore, groundwater does not participate in the formationof all the soils (Fig. 1). The soil cover of the territoryinvestigated is composed of leached chernozems (pit 1,on the most elevated part of the area); podzolized

leached chernozems (pit 2, the upper part of the slope);deeply gleyed podzolic chernozem-like soil (pit 3,lower tier of the slope), and gleyic podzolic chernozem-like soil (pit 4, the central part of an oval depression)(Fig. 2). These names need additional substantiation.The necessary explanation is given below after the con-sideration of the results obtained.

The upper horizons (0 to 30 cm) of all the soils stud-ied are clayey–coarse silty loamy clayey. The parentrocks have the same or similar particle-size composi-tion. Taking into account this circumstance, the singlefactor determining the specific features of the genesisof these soils appears to be the stagnant–percolativehydrological regime. The redistribution of moisture inthe soils is related to the topography of the territory.Water periodically stagnated in depressions causing thedevelopment of anaerobiosis and gley in the upper hori-zons of their soils.

RESULTS AND DISCUSSION

Morphology of the soils and their particle-sizecomposition.

The descriptions of the pits of the typicalsoils demonstrate their specific macromorphologicalfeatures.

Pit 1. Loamy leached chernozem on calcareous clayloam. Cropland, corn for silage. A well drained eleva-tion on the second floodplain terrace of the Oka River(Fig. 3).

Ap, 0–30 cm. Fresh, dark gray, subangular-blocky–granular, loamy clayey, many roots. The tran-sition is clear by the lower boundary of the tillage.

A1, 30–58 cm. Fresh, dark gray with dark brownhue, crumb–granular, loamy clayey, homogeneousin color. The boundary is wavy. The transition is dis-tinct and identified by color.

AB, 58–75 cm. Fresh, gray–dark brown with yel-low hue, weak crumb structure, loamy clayey, oval

Fig. 1.

A scheme of the distribution of the pits and the lithol-ogy of the catena. Designations:

1

—Carboniferous lime-stones;

2

—Jurassic clays;

3

—Cretaceous sands;

4

—sandyalluvium;

5

—loess-like loam.

Fig. 2.

Soils of the Ryazan Soil-Hydrological station. Designations:

1

—leached chernozem, pit 1;

2

—podzolized leached cher-nozem, pit 2;

3

—Deeply gleyed podzolic chernozem-like soil, pit 3;

4

—gleyic podzolic chernozem-like soil, pit 4.


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GENESIS, HYDROLOGY, AND PROPERTIES OF SOILS 919

mottles of dark-colored material—krotovinas. Thetransition is distinct.

B, 75–92 cm. Slightly dry, brown, fine prismatic,loamy clayey, effervesces with HCl, many carbon-ate filaments. The transition is distinct and seen bycolor.

BC, 92–110 cm. Slightly dry, brown with yellowhue, loamy clayey, weak crumb structure, porous,effervesces with HCl. The transition is gradual.

Cca, 110–125 cm. Dry, pale-yellow, heavyloamy, porous, roughly effervesces with HCl, finecarbonate nodules (“zhuravchiki”).In all the horizons of the leached chernozem, cutans

were not found.Pit 2. Weakly and deeply gleyed heavy loamy pod-

zolized chernozem. The upper part of the gentle slope.Cropland (corn for silage).

Ap, 0–28 cm. Fresh, dark gray, weak crumbstructure, loamy clayey, friable. The transition isdistinct by the boundary of the plow layer.

A1fs, 28–44 cm. Fresh, grayish–dark brown, finecrumb structure, loamy clayey, compact, few Mn–Fenodules, rather compact. The transition is gradual.

A1A2, 44–58(64) cm. Fresh, loamy clayey, gray-ish mottles on the brown background, many Mn–Fenodules, frequently in clusters. Compact. The tran-sition is clear.

A2B, 58(64)–70(78) cm. Weakly moist, grayishloam with many whitish gray mottles of intensepodzolization, few Mn–Fe nodules, compact, withfragments of the brown illuvial horizon. The bound-ary is indistinct and sinuous.

B, 70(78)–100 cm. Moist, light brown, loamyclayey. Large brown–dark gray humus–clay cutans,very compact. The transition is gradual.

BC, 100–125 cm. Moist, brown-gray, compact,clayey loamy, with few gley punctuations.Pit 3. Deeply gleyed loamy clayey podzolic cher-

nozem-like soil on noncalcareous loess-like clay loam.The lower tier of a gentle slope. Cropland (corn indepressed state). Abundant weeds:

Matricaria inodora

L., ribwort (

Plantago lanceolata

L.), chickweed (

Stel-laria media

L.), corn sowthistle (

Sonchus arevensis

L.),common foxtail (

Alopecurus pratensis

L.), creepingthistle (

Cirsium arvense

L.), meadow-grass (

Poa prat-ensis

L.), cooksfoot (

Dactilis glomerata

L.), fieldhorsetail (

Equisetum arvense

L.), and timothy grass(

Phleum pratense

L.).Water stagnates on the soil surface for 1–2 weeks.

The soil does not effervesce with HCl.Av, 0–2 cm. Sod, weakly pierced by roots.Ap, 2–18 cm. Fresh, dark gray with slight dove

hue, loamy clayey, crumb–granular structure, manyroots, friable. The boundary is even, the transition isclear and identified by color.

A1, 18–30 cm. Weakly moist, gray, loamyclayey. The boundary is wavy, the transition isclearly seen by color.

A1A2, 30–52 cm. Weakly moist, large whitishmottles on the grayish background, weak crumbstructure, compact. The boundary is wavy. The tran-sition is clear and identified by color and texture.

A2fs, 52–68 cm. Weakly moist, whitish withpale hue, loamy, weak fine platy structure, manyMn–Fe nodules. The boundary is tonguing, the tran-sition is noticeable by color and consistence.

A2fs, 68–82 cm. Moist, ocherous–brown, loamy,fine prismatic. Weak gleying along fissure walls.Mn–Fe nodules, gray cutans. The boundary is wavy,the transition is noticeable by color.

B1g'', 82–100 cm. Moist, ocherous–brown,loamy clayey, fine prismatic, dark brown humuscutans on ped faces. Fine mottles of gleying andamorphous manganic mottles on the walls of fis-sures. The boundary is even, the transition is notice-able by color.

Fig. 3.

The moisture regime of the loamy clayey leachedchernozem (I) and light clayey gleyic podzolic chernozem-like (II) soil during a humid year (the moisture is in vol%and categories). Designations:

1

—<0.7 field capacity (FC);

2

—0.7 FC–0.95 FC;

3

—0.95 FC–1.05 FC;

4

—1.05FC

−

0.8 FC;

5

—0.8 FC–FC;

6

—FC (perched groundwater).

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B2g'', 100–125 cm. Moist, grayish-ocherous,loamy clayey, coarse prismatic, many Mn–Fe segre-gations. Many fine mottles of gleying.

BCg', 125–147 cm. Moist, dark brownish–ocher-ous, loamy clayey, few mottles of gleying, Mn–Fesegregations.Pit 4. Gleyic loamy clayey podzolic chernozem-like

soil on noncalcareous loess-like loamy clay. The bot-tom of a large oval depression with steep slopes.Weakly bogged layland. The vegetation is representedby ribwort (

Plantago lanceolata

L.), chickweed (

Stel-laria media

L.),

Galeopsis speciosa

L., water forget-me-not (

Myosotis palustris

L.), meadow-grass (

Poapratensis

L.), common foxtail (

Alopecurus pratensis

L.), and shady horsetail (

Equisetum pratense

Ehrh.).In the spring, after the snow melting, surface water

stagnates in these soils for 3–4 weeks. The soil does noteffervesce with HCl.

Av, 0–2 cm. Shallow slightly dense sod.A1g', 2–28 cm. Fresh, dark gray, weak platy,

loamy clayey, crumb–granular structure. Manyrusty–ocherous mottles and plant roots, friable. Theboundary is wavy, the transition is noticeable bycolor.

A1A2'fs, 28–48 cm. Fresh, grayish white, loamyclayey, weak crumb structure, weakly compact,weakly platy, many iron nodules. The boundary iseven, the transition is noticeable by color.

A2fs, 48–60 cm. Weakly moist, dark gray andrusty–ocherous mottles on a whitish background,silty loamy, platy structure, many Mn–Fe nodules.The boundary is tonguing, the transition is notice-able by color and consistence.

A2B''fs, g'', 60–82 cm. Moist, dove mottles onthe brown background, intense gleying along verti-cal fissures and root channels, loamy, iron nodulesand black mottles, brownish gray cutans. Theboundary is wavy, the transition is noticeable bycolor.

B1g'', 82–100 cm. Moist, ocherous rusty, accu-mulation of fresh iron hydroxide in some places,amorphous Mn mottles, loamy clayey. Many largedark colored humus cutans with living plant roots onthem. The boundary is wavy, the transition is notice-able by color.

B2g''', 100–140 cm. Moist, loamy clayey, accu-mulation of fresh iron hydroxide on the ocherous-rusty background, amorphous Mn mottles and somemottles of gleying. Cutans are less abundant than inthe overlying horizon.

Cg''', 140–160 cm. Moist, brown with few ocher-ous mottles, loamy clayey, dark colored accumula-tions of Mn. Weak marble-like gleying.The profile of the leached chernozem is homoge-

neous in terms of the physical clay (43–50%) andcoarse silt content fraction (42–46%). The fraction ofmedium sand is almost absent. The content of the clay

fraction is maximal in the humus horizons (28–34%); itgradually decreases downward and amounts to 18–19%in the parent rock. The clay and coarse silt fractionspredominate. The texture of the gleyed podzolic cher-nozem-like soils is different from that of the leachedchernozem. In the latter, the content of fine sanddecreases and that of the coarse silty (loess-like) frac-tion drastically increases in the podzolic and pod-zolized horizons. The content of the clay fraction ismuch lower in the podzolic horizons. The clay fractiondistribution along the profile of the chernozem-likesoils allows us to suggest the participation of lessivagein their formation. However, the removal of clay fromthe podzolic horizons may also be related to theirintense iron depletion due to gleying.

Thus, the particle-size analysis indicates the signifi-cant differences in the formation of the leached cher-nozem and gleyed podzolic chernozem-like soils(Table 1). In the leached chernozem, in the course ofthe soil formation, clay is accumulated almost in all thehorizons within the 90-cm thickness. In the other case,the intense podzolization under the conditions of thestagnant–percolative water regime causes clay removalfrom the eluvial horizons, the particle-size compositionof the podzolic and podzolized horizons to becomelighter, and clay to be somewhat accumulated in theB horizon.

The most essential conclusions based on the analy-sis of the morphology of the soils studied are givenbelow. Within the catena investigated, the increase (inspace) of gleying in the soils is accompanied by a reg-ular increase in the degree of the soil podzolization.Evidently, in this case, the genetic relationship betweenthese soils representing a natural continuum is mani-fested. The thickness of the podzolic and podzolizedhorizons turn out to be essential and may reach morethan 50 cm. The maximal thickness of the A2 and pod-zolized horizons (A1A2 + A2 + A2B) was found in thegleyic podzolic chernozem-like soil—12 and 54 cm,respectively (Table 2). The data obtained show that thedistinguishing characteristics of these soils are the fol-lowing: (1) the presence of thick whitish acid eluvial(i.e., podzolic) horizons in their profiles, (2) the pres-ence of numerous Mn–Fe nodules in the eluvial hori-zons (Table 3), (3) the presence of humus cutans in theilluvial horizons, and (4) distinct morphochromaticsigns of gley. For the leached chernozem, the efferves-cence with HCl from a depth of 75–80 cm is character-istic, unlike the gleyed chernozem-like podzolic soils,which do not effervesce at all. The presence of Mn–Fenodules and humus illuviation cutans in their profileserves as one more piece of evidence that they areformed under the strong influence of gley [9]. The max-imal amount of nodules is recorded in the A2 horizon(1.18% of the soil mass). In the adjacent horizons sub-ject to podzolization, the contents of nodules do notexceed 0.18–0.48%. The absence of Mn–Fe nodules inthe profile of the leached chernozem attest that, in this


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soil, unlike in the chernozem-like soil, gleying does nottake part in the soil formation [18].

The results obtained show that, according to themorphological characteristics, the gleyed podzolicchernozem-like soils principally differ from the zonal

forest-steppe soils (leached chernozems). These differ-ences are described below (Table 3).

Density, porosity, and water permeability.

Theleached chernozem is favorable in terms of the density(1.20 g/cm

3

) and porosity (54%) of the upper 0- to

Table 1.

The particle-size composition (Kachinskii method) of the leached chernozem and gleyed loamy clayey podzolicchernozem-like soil in the northern forest-steppe (Ryazan oblast, % of absolutely dry noncalcareous soil)

Horizon Depth, cmContent of fractions, %; size, mm Accumulation (+)

and removal (–) of clay, %1–0.25 0.25–0.05 0.05–0.01 0.01–0.005 0.005–0.001 <0.001 <0.01

Leached chernozem, pit 1

Ap 0–15 2 10 45 7 8 28 43 +47

15–27 2 5 47 7 7 32 46 +68

A1 30–40 0 10 42 9 5 34 48 +79

45–56 0 10 49 5 15 21 41 +11

AB 60–70 0 9 40 12 18 21 51 +11

B 80–90 0 9 46 10 13 22 45 +16

BC 95–105 0 2 44 16 20 18 54 –5

Cca 112–124 0 5 45 14 17 19 50 0

Deeply gleyed podzolic chernozem-like soil, pit 3

Ap 4–16 0 0 44 18 6 32 56 +78

A1A2 20–30 1 1 45 4 21 28 53 +55

A2fs 54–63 0 7 61 11 12 9 32 –50

A2B'fs,g' 70–80 0 9 60 10 10 11 31 –39

B1g' 85–95 0 1 44 16 18 21 55 +17

B2g" 102–110 0 8 47 17 10 18 45 0

Gleyic podzolic chernozem-like soil, pit 4

A1g' 3–25 0 1 45 17 10 27 54 +17

A2'fs 35–41 1 0 48 14 15 22 51 –4

A2"fs 50–60 1 2 62 14 8 13 35 –43

A2Bfs,g' 65–80 1 9 55 7 15 13 35 –43

B1g"' 85–95 0 4 49 5 13 29 47 26

B2g" 102–116 0 2 49 13 13 23 49 0

Table 2.

The morphometry of the leached chernozem and differently gleyed podzolic chernozem-like soils

Soil

Thickness of genetic horizons and gleying of profileA1 + A1A2 +

A2B*, cmA1 A2 A1A2 A2B depth of gleying signs and degree of gleying

Leached chernozem 58 No

Weakly and deeply gleyed leached chernozem

44 No 14 12 g'—from a depth of 100 cm; few very small mottles

26

Deeply gleyed podzolic cher-nozem-like soil

30 16 22 24 g"—from a depth of 82 cm; many mottles of gleying

52

Gleyic chernozem-like pod-zolic

28 32 No 22 g'"—from a depth of 60 cm; intense gleying 54

* The total thickness of the eluvial horizon.

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50-cm humus horizon (Table 4). Its water permeabilityis high and amounts to 0.45 m/24 h. Gleying distinctlyaffects these physical properties. In the gleyed podzolicchernozem-like soils, from a depth of 50 cm, the den-sity increases and the porosity decreases due to gleying.The filtration coefficient (

Kf

) is low in all the horizonsof the soil profile (Table 4). In the deep layers, its valuebecomes equal to that of the waterproof horizon(0.05 m/24 h).

Elements of the water regime.

The plowed leachedchernozem develops under the conditions of a nonper-colative water regime since it has no catchment area(Fig. 3). During the spring periods of humid years, afterthe snow melting, the moisture of the soil deeper than50–60 cm turns out to be lower than the field watercapacity and corresponds to the value between themoisture of the capillary break and the field capacity.During the whole summer–autumn period, in the50 (70)- to 150-cm-thick layer, the soil moisture islower than the capillary break moisture. In the springand, frequently, in the summer and autumn, the cher-nozem-like soils, unlike the leached chernozems, havea stagnant–percolative regime. The hydrological stud-ies showed that the anaerobic phase in these soils wasmainly observed in early spring (late March—the lastdecade of April). In the 0- to 30 (50)-cm-thick layers ofthese hydromorphic soils, their moisture exceeds thefield capacity or water fills their pores forming a stablehorizon of perched surface water in the plow layer(Table 5, Fig. 3). Thus, these soils develop under condi-tions of the stagnant–percolative water regime. Duringthe period of water stagnation, anaerobic conditionsarise only in the podzolic chernozem-like soils, and theredox potential of these soils sharply falls (Table 6).

Therefore, in the case considered, the only factor ofthe origin of the gleyed podzolic chernozem-like soils

(under other equal conditions) is the relief and associ-ated redistribution of the surface runoff (mainly in thespring) and the accumulation of free water on the soilsurface and in the eluvial horizons. Just these particu-larities of the hydrological regime and of the dynamicsof the redox potential determine the most important dif-ferences in the morphology and properties of the solidphase of the two groups of soils considered—theleached chernozems (automorphic) and differentlygleyed podzolic chernozem-like soils (hydromorphic).

Table 3.

The morphological features of the leached cher-nozem and gleyed podzolic chernozem-like soils in the for-est-steppe (northern Ryazan oblast)

Morphological features

Leached chernozem

Differently gleyed podzolic chernozem-like

soils

Differentiation of profile

Not expressed Eluvial-illuvial

Gleying Absent Distinct morphochro-matic signs of gleying

Cutans Absent Humus cutans

Mn-Fe nodules Absent Presence in all light (whitish) horizons

Carbonate nod-ules

Few nodules Absent

Effervescence with HCl

From a depth of 75 cm and deeper

No effervescence along the whole profile

Podzolizatio Absent Thick A2 horizons

Table 4.

The density of the solid phase, bulk density, poros-ity, and water permeability of the leached chernozem andgleyic podzolic chernozem-like soil

Depth, cm

Density of the solid

phase

Bulk density Porosity,

%

Coeffi-cient of fil-

tration, m/24 hg/cm

3

Leached chernozem, pit 10–5 2.44 0.99 59.435–10 2.45 1.10 55.10

10–20 2.60 1.15 55.77 0.4520–30 2.66 1.17 56.0230–40 2.68 1.30 51.4940–50 2.69 1.32 50.9350–60 2.69 1.35 49.8160–70 2.67 1.39 47.9470–80 2.67 1.41 47.1980–90 2.66 1.44 45.86 0.2290–100 2.68 1.46 45.52

100–110 2.70 1.44 46.67110–120 2.69 1.47 45.35120–130 2.69 1.46 45.72 0.09130–140 2.69 1.49 44.61140–150 2.69 1.48 44.98

Gleyic podzolic chernozem-like soil, pit 40–5 2.42 1.02 57.95–10 2.42 1.13 53.3 0.27

10–20 2.42 1.13 53.320–30 2.58 1.15 55.430–40 2.63 1.28 51.340–50 2.68 1.43 46.650–60 2.68 1.48 44.860–70 2.69 1.50 44.270–80 2.69 1.51 43.980–90 2.69 1.46 45.7 0.1390–100 2.69 1.48 45.0

100–110 2.70 1.49 44.8110–120 2.70 1.50 44.4120–130 2.70 1.53 43.3 0.05130–140 2.70 1.51 44.1140–150 2.70 1.55 42.6


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Chemical and physicochemical properties.

Owing to the stagnation of surface water and a sharpdrop of the redox potential, the gleyed soils of depres-sions have very different morphological, chemical, andphysicochemical properties of the solid phase as com-pared to the properties of the leached chernozems.Under the influence of intense gleying under the stag-nant–percolative water regime, calcium and magne-sium ions are strongly leached. The profile of thegleyed soils becomes free from nonsilicate compoundsof alkaline-earth metals; carbonate nodules are also absent.The pH values along the whole profile of the gleyed pod-zolic chernozem-like soils are lower by 1–2 units versusthe leached chernozems (Table 7). The hydromorphicpodzolic chernozem-like soils differ from the leachedchernozems in the higher hydrolytic acidity of the sur-face humus horizons.

As a result of gleyzation, calcium, magnesium, iron,aluminum, manganese, and other elements are leachedand the base saturation of the podzolic and podzolizedhorizons decreases. It is essential that all the horizons,including the light acid eluvial ones, in the soils consid-ered do not contain sodium among the exchangeablecations.

The soils investigated are also distinguished by thepattern of the humus distribution. In the profile of theleached chernozem, the humus content graduallydecreases with depth. In the gleyed podzolic cher-nozem-like soils, unlike in the leached chernozem, thehumus content is maximal in the 35- to 50-cm-thicklayer. In the A1 horizon, the humus content is equal toor higher than that in the same horizon of the leachedchernozem. With depth, it sharply decreases. This factis explained by the transformation of organic matterupon gleying, the increase in the content of the mobilefraction, and by its migration with infiltration water.The morphogenetic and analytical studies show that,under the stagnant–percolative water regime, soils witha well-pronounced differentiation of their profiles andgleying develop. This conclusion is confirmed by thedata on the total composition of the soils considered(Table 8).

Thus, the eluvial horizons of the gleyed podzolicchernozem-like soils are formed upon the intenseleaching of iron, aluminum, calcium, manganese, phos-phorus, and other elements and a relative increase (ascompared to the parent rock) in the silica content. Incontrast to the chernozem-like soil, in the leached cher-nozem, the elements mentioned are distributed withintheir profiles rather uniformly.

Agroecological assessment.

The influence ofwaterlogging of soils on the crop yield was evaluatedby counting using the method of small squares in 5 rep-licates (Table 9).

The data obtained reflect the common trend of adecreasing yield as the degree of waterlogging rises.The differences in the productivity between the leachedchernozem and gleyic podzolic chernozem-like soils

are significant (

p

= 0.90). Despite the poor growth ofcrops on the gleyic podzolic chernozem-like soils, thedrainage of these soils may be a useful measure in thecases when the area of these soils does not exceed10% of the whole territory occupied by the leachedchernozem.

CONCLUSIONS

In depressions of the northern forest-steppe, mineralhydromorphic soils with light-colored acid eluvial hori-zons are widely spread among the chernozems. Theirgenesis, properties, and regimes drew the attention ofresearchers long ago.

Table 5.

The moisture reserves in the leached chernozemand podzolic chernozem-like soils during the spring periodof 2003 (northern forest-steppe, Ryazan oblast)

Layer, cm

Moisture re-serves at the

minimal water capacity, mm

Moisture reserves, mm

Apr. 19 Apr. 29 May 21

Leached chernozem

0–30 78 111 96 76

30–50 60 70 68 65

50–100 165 177 160 162

0–100 303 358 324 303

Deeply gleyed podzolic chernozem-like soil

0–30 81 123 119 96

30–50 56 78 69 56

50–100 160 175 169 156

0–100 297 376 350 303

Gleyic podzolic chernozem-like soil

0–30 90 157 146 104

30–50 50 90 84 68

50–100 170 183 178 173

0–100 315 430 408 345

Table 6.

The redox potential of the leached chernozem anddeeply gleyed podzolic chernozem-like soil, mV (

n

= 5;mean values are given)

Depth, cm Apr. 19 May 4 May 16

Loamy clayey leached chernozem

0–2 468 572 503

18–20 435 495 516

Light clayey gleyic chernozem-like podzolic soil

0–2 –35 442 523

18–20 –161 415 527

924


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ZAIDEL’MAN et al.

At the earlier stage of scientific soil science devel-opment, the prominent representatives of theDokuchaev school referred soils with such morphologyand properties to “steppe” podzols. In particular, Koss-ovich [16] emphasized the specific conditions of soilformation in steppe depressions: “In depressions,waterlogging is mainly restricted to the spring periods.At the period of snow melting, the steppe is studdedwith snow spots, which soon are transformed to smalllakes, and water is held in them up to halfway throughMay and longer” (p. 249); “chernozems of the depres-sions, under their moisture conditions, may be easilypodzolized in their upper layers and transformed intosoils of other types” (p. 251); and, “with approachingthe deepest part of a depression, the leaching of thechernozem increases, and, in the latter, signs of its deg-radation and transformation to a podzolic soil appear”(p. 253). However, until now, the classification of thesesoils remains not fully elaborated, and many problemsof their genesis have been incompletely solved. There-

fore, these soils are determined as solodized, pod-zolized, gley, surface gley–eluvial, and pseudopod-zolic.

Undoubtedly, the genesis of the soils studied is notrelated to solodization for two reasons. First, all thesoils investigated do not contain sodium in the soilexchange complex. Second, all the horizons of thechernozem-like soils are acid. As for the known diag-nostic criterion of solodization according to Gedroitsmethod based on the determination of the content ofamorphous silica (extracted by 5% NaOH), the latterwas not used in this work, since it was found to be non-specific. Bazilevich [2] showed that alkaline extractionaccording to Gedroits method was unsuitable for test-ing of solodized soils and solods, since it (irrespectiveof the soil genesis) extracts proportionally increasingcontents of amorphous silica with acquisition of their“meadow” properties. The data obtained using the alka-

Table 7.

The humus content and physicochemical properties of the leached chernozem and differently gleyed podzolic cher-nozem-like soils

Horizon, depth, cm

Acidity Exchangeable bases Base saturation Humus

pH hydrolytic Ca

2+

Mg

2+

Na

+

%HCl mmol/100 g of soil

Pit 1. Leached chernozem

Ap, 3–12 7.20 6.28 1 53.2 12.4 0 98.4 4.38

Ap, 17–27 6.92 6.29 1 46.5 12.4 0 98.2 4.57

A1, 32–38 7.18 5.90 2 37.6 14.4 0 97.2 2.88

A1, 42–56 6.72 5.50 2 31.0 17.0 0 95.7 2.43

AB, 60–70 6.84 5.13 3 29.6 20.1 0 95.2 1.79

B, 80–90 6.62 5.08 2 N.d. 0.14

BC, 95–108 7.98 7.10 0

"

0.13

Cca, 115–118 8.19 7.18 0

"

0.13

Pit 3. Deeply gleyed podzolic chernozem-like soil

Ap, 3–15 5.90 4.85 9 28.4 10.7 0 81.0 6.34

A1, 20–28 5.90 4.80 10 22.6 8.4 0 75.6 6.21

A1A2, 35–50 5.85 4.55 13 7.4 4.5 0 50.1 5.90

A2fs, 54–64 5.75 4.50 5 6.8 3.9 0 70.3 0.66

A2Bfs, 72–80 5.95 4.65 3 10.1 5.5 0 85.1 0.62

B1g', 85–95 6.00 4.75 3 16.2 12.1 0 91.2 0.40

B2g", 110–118 5.95 4.75 3 16.8 13.4 0 91.4 0.29

Pit 4. Gleyic podzolic chernozem-like soil

A1g', 12–28 5.52 4.08 10 30.4 9.6 0 79.4 5.83

A2'fs, 32–39 5.51 4.10 3 9.7 6.5 0 82.9 2.69

A2"fs, 50–58 5.66 4.23 4 10.3 8.0 0 80.6 0.43

A2Bfs,g", 65–78 5.80 4.15 3 14.4 9.7 0 84.4 0.38

Bg", 85–95 5.90 4.23 3 18.4 14.2 0 87.8 0.28

B2g", 104–112 6.15 4.27 3 20.4 18.2 0 93.5 0.17

pHH2O


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2007


line extract attest to the degree of excessive moistureand gleying of soils but not to their solodization.

The studies performed revealed that, in the northernforest-steppe, acid chernozem-like soils with eluvial oreluvial–illuvial differentiation of their profiles arewidespread. These soils develop under the stagnant–percolative water regime and are characterized by theintense leaching of alkaline-earth metals, iron, alumi-num, manganese, phosphorus, and clay from all thehorizons. As a result, the soils become acid, and light-colored acid eluvial horizons with different thicknessesare formed due to gleyzation arising because of waterstagnation in depressions. The mechanism of this pro-cess was studied in detail earlier under natural condi-tions and in model experiments [6–8].

The acid soils with light-colored (whitish) acid hori-zons and differentiated profiles that are spread indepressions among the leached chernozems should notbe considered as soddy-podzolic soils, since they havea thick humus horizon (up to 54 cm), which is probablyinherited from chernozems, and a high humus content(5.8–6.6%). The proposal to name these soils surfacegley–eluvial seems to be insufficiently substantiated,since, first, it does not reflect the presence of thick pod-zolic horizons in these soils. Second, the determinationas a gley–eluvial soil proper appears to be inexpedient

because, in any case, the gley horizons are leached ofiron and manganese. By introducing gley into the nameof these soils, we assert that they are eluvial. Thus,some unjustified tautology appears in their definition.In addition, this name does not reflect the relationshipof these soils with the background chernozems.

The use of the term pseudopodzolic soils introducedby Gerasimov [3] and Zonn [13] into Russian soil sci-ence is unjustified, because these soils should have fea-tures of lessivage. However, the signs of this processmay not always be traced in the soils considered. Theyhave a limited distribution. In Akhtyrtsev’s work [1]cited above, the features of lessivage were present onlyin 50% of the pits analyzed, which were located in thedepressions with gley podzolic and podzolized hori-zons. Therefore, lessivage turns out not to be a stablesoil-forming process but a facultative phenomenon dueto gleying at its initial stages. This problem was consid-ered in our earlier work [9, 10].

The soils studied are also not referred to podbels,since the latter soils are a genetic constituent of the soilcover of the Far East associated with the backgroundbrown podzolic soils. The gleyed podzolic chernozem-like soils occur with the leached chernozems. “Podbelsare characteristic of the coniferous–broad-leaved for-ests in the southern Far East,” and gleyed podzolic cher-

Table 8.

The total chemical composition of the leached chernozem and gleyic podzolic chernozem-like soil, % of calcinednoncalcareous sample

Horizon, depth, cm

Hygroscopic moisture, % SiO

2

Al

2

O

3

Fe

2

O

3

CaO MgO MnO P

2

O

5

Leached chernozem, pit 1

Ap, 3–12 3.05 74.83 9.80 6.11 1.38 0.82 0.29 0.37

A1, 32–38 3.19 73.04 11.24 5.84 1.35 0.78 0.08 0.34

AB, 60–70 2.82 71.81 11.00 6.15 1.42 0.78 0.07 0.31

Cca, 115–123 2.62 76.31 10.12 6.31 1.44 1.03 0.13 0.29

Gleyic podzolic chernozem-like soil, pit 4

A1g', 3–9 3.18 76.53 10.74 2.86 1.18 0.07 0.16 0.09

A2'fs, 32–39 3.18 78.26 10.76 2.75 1.17 0.09 0.08 0.07

A2"fs, 45–58 1.00 80.28 10.58 2.68 1.14 0.86 0.08 0.07

B2g', 104–135 2.68 75.30 12.68 4.42 1.19 1.00 0.06 0.05

Table 9.

Yield of barley and corn for silage (tons/ha) on the leached chernozem, podzolized leached chernozem, deeply gleypodzolic chernozem-like, and gleyic podzolic chernozem-like soils

Crop

Soil

leached chernozem

podzolized leached chernozem

deeply gley podzolic chernozem-like

gleyic podzolic chernozem-like

Corn for silage, 2003 536

±

120 Not determined 484

±

106 Complete soaking

Barley for grain, 2004

18.2

±

2.3 16.1

±

1.2 14.1

±

2.8 7.5

±

2.0

926


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ZAIDEL’MAN et al.

nozem-like soils develop under the forest-steppe ofEuropean Russia. Podbels contain 10–20% coarse(>3 mm) ferruginous nodules in their A2 or E1 hori-zons, and their profiles are clearly differentiated in rela-tion to their acidity [15]. The content of these nodulesin the same horizons of the gleyed podzolic chernozem-like soils does not exceed 3.0%. Their profile, unlikethat of the leached chernozems, is not differentiatedwith relation to their acidity. Lastly, in the northern for-est-steppe, the most drained territories are occupied byleached chernozems, while, in the southern taiga of theFar East, they are occupied by podbels with well-pro-nounced podzolic horizons.

Evidently, all the authors assert the essential role ofgleying in the formation of gleyed podzolic chernozem-like soils. Undoubtedly, this standpoint should be sup-ported with some comments. Under the conditionsdescribed, gleying proceeds in soils on acid parentrocks under the stagnant–percolative regime and resultsin the leaching of iron, aluminum, calcium, magne-sium, manganese, phosphorus, potassium, and otherelements. Frequently, the clay fraction is leached, and,in the surface layers, the quartz content increases;hydroxide films (cutans) are lost. As a result, light-col-ored acid eluvial (podzolic) horizons are formed irre-spective of the soil texture. The described facts reflectthe unitary mechanism of the development of the light-colored acid eluvial horizons in soils of all the naturalzones of the earth [6−9]. They refer equally to the zoneof chernozems. Precisely for this reason, the propertiesof the solid phase of the light-colored acid eluvial (pod-zolic) horizons are always identical to those of the A2or A2g horizons in podzolic (or waterlogged podzolic)soils. The preceding allows assuming that the namechernozem-like podzolic soil not only reflects theirgenesis but most completely corresponds to the princi-ples of the substantive-genetic classification of soils.The results of Akhtyrtsev [1], Denisova and Lebedeva[4], and other researchers, as well as our data, showthat, in the European forest-steppe, among mineralhydromorphic soils, gleyed podzolic chernozem-likesoils with light acid eluvial (podzolic) horizons arewidely spread. The main factor of their formation is theaccumulation of surface water on the interfluves (espe-cially in depressions), periodic excessive moistening,anaerobiosis, and gleyzation under conditions of a stag-nant–percolative water regime. These podzolic cher-nozem-like soils, which are widespread in the forest-steppe, radically differ in genesis both from typicalchernozems and leached chernozems. They haveadverse agroecological properties because of their reg-ular excessive moisture.

In the area of the podzolic chernozem-like soils,crops are often exposed to suppression or lost becauseof the excess of water depending on the degree of gley-ing of the soils in the years with normal precipitationand, especially, in moist years. Thus, the gleyed pod-zolic chernozem-like soils radically differ from thezonal leached chernozems in the type of the water

regime, the properties of the solid phase, and the agro-ecological properties. These soils—a quite widespreadcomponent of the soil cover in the forest-steppe—werenot reflected in the classifications of soils of the USSRand the Russian Federation [14, 15] and in some others.The gleyed podzolic chernozem-like soils are sug-gested to be considered as a new individual type of soilswidespread in the forest-steppe. Probably, it also occursin regions of the northern part of the steppe zone. Lateron, it is expedient to differentiate this new type of soilsaccording to the degree of hydromorphism and pod-zolization, the parent rocks, the regional particularities,and other features. They will reflect the diversity of thegleyed chernozem-like podzolic soils in the forest-steppe and steppe.

ACKNOWLEDGMENTS

This work was supported by the Russian Foundationfor Basic Research (project no. 05-04-48157).

REFERENCES

1. B. P. Akhtyrtsev, “The Soils of Depressions in the Cen-tral Russian Upland and the Tambov Plain,” Poch-vovedenie, No. 9, 14–26 (1974).

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8. F. R. Zaidel’man, “Formation of Light-Colored AcidEluvial Horizons in Soil Profiles,” in Scientific Discover-ies in 1995–1997: Overviews (Moscow, 1997), p. 14[in Russian].

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EURASIAN SOIL SCIENCE Vol. 40 No. 9 2007


Forest and Forest-Steppe Zones (Mosk. Gos. Univ.,Moscow, 2001) [in Russian].

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13. S. V. Zonn, “Podzol and Pseudopodzol Formation and ItsManifestation in Soils of the USSR,” Pochvovedenie,No. 3, 3–11 (1969).

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Documents

Genesis, hydrology, and properties of soils in mesodepressions waterlogged by surface water in the northern Ryazan forest-steppe