Status of “Black soils” in the Republic of Moldova - Ciolacu Tatiana

Status of “Black soils”
in the Republic of Moldova
dr. Ciolacu Tatiana

1. Overview of Black soils in the Republic of Moldova
The group of “Black soils” in the genetic and functional sense
comprises chernozems, castanozemes, phaeozems et. al. –
predominant automorphic polymineral soils, with long-lasting soil
formation process of humus accumulation in which the C:N ratio
is in the ranges of 8-16.
Black soils in the Republic of Moldova:
 chernozems;
 forest grey soils;
 alluvial soils;
 deluvial soils;
 cernoziomoid soils;
 rendzines.
Definition of Black soils:

Soil digital map of the Republic
of Moldova
Soil subtype
Number
of Areas
Surface, ha
% of total land
area
Weighted
average bonitet
Brown luvic soil 150 13619.19 0.44 47.35
Brown typical soil 107 4024.84 0.13 56.37
Grey albic soil 37 2510.28 0.08 39.35
Grey typical soil 2160 124125.87 4.00 46.75
Grey molic soil 2658 156253.57 5.03 63.72
Argillic chernozem 1968 108051.73 3.48 75.52
Leached chernozem 8024 367364.27 11.83 74.34
Typical chernozem 4599 249770.20 8.04 81.79
Xerophyte-wooded
chernozem 183 18524.55 0.60 81.14
Ordinary chenozem 10294 660130.05 21.26 66.16
Calcareous chernozem 14586 708939.16 22.83 51.73
Cernoziom sudic 17 1017.48 0.03 48.56
Typical gley soil 412 2962.71 0.10 20.81
Leached chernoziomoid soil 1597 20652.80 0.67 69.52
Typical chernoziomoid soil 10891 109194.68 3.52 82.66
Calacreous rendzina 300 9477.73 0.31 36.12
Leached rendzina 109 3180.09 0.10 37.50
Grey vertic soil 46 1150.52 0.04 50.00
Vertic chernoziom 624 16880.52 0.54 46.57
Vertic chernoziomoid soil 40 861.67 0.03 44.00
Molic solonetz 235 3310.59 0.11 33.75
Hidric solonetz 53 1769.05 0.06 31.22
Hidric solonchak 157 2718.62 0.09 9.91
Molic solonchak 27 409.62 0.01 34.00
Alluvial mollic soil 2022 142411,35 4.58 78.04
Alluvial stratified soil 1023 104754.34 3.37 72.01
Alluvial vertic soils 132 8449.15 0.27 44.40
Alluvial hydric soil 147 16104.23 0.52 22.66
Alluvial peaty soil 46 6704.25 0.22 20.10
Delluvial ocric soil 304 11957.69 0.39 81.11
Delluvial molic soil 1579 56487.09 1.82 82.32
Alluvial gleyic soil 593 34411.66 1.11 23.60
Anthrosols & technosols 45 381.13 0.01 24.00
Active landslides 3171 110244.69 3.55 5
Stabilized landslides 566 22977.26 0.74 27.84
TOTAL 70475 3104723.21 100 62.23
General characteristic of soil subtypes of the
Republic of Moldova

Classification of Black soils in the Republic of Moldova
Chernozems
• predominant soil type in the
Republic of Moldova;
• occupy up to 77.83% of the area;
• distinguished by:
 black color
 granular structure
 thick humus layer (with
humus content >1%) in range
of 60-100 cm

Water regime
Chernozem subtypes
(by carbonates level):
leached
typical
ordinary
calcareous
The Republic of
Moldova climate map
vertic chernozems
Specific conditions:
under oak forests (in
contact with gray soils)
argillic chernozem
Specific conditions:
mother rock - fine
clays
Conventional signs:
I – Northern Zone, moderately warm and humid
II – Central Zone, warm and moderately humid
III – Southern Zone – warm and dry

Argillic Chernozems
Argillic chernozem (acad. Ursu A.)
• were formed under oak forests with a well-developed
grass cover;
• upper parts of interfluvial plateaus with elevations of
210 to 290 m on the Nothern Plateau, Nistru Upland
and in the Central Moldovan Upland - Codrii Region;
• occupy about 50 thousands ha (2,75%);
• superficial horizon is mollic, with no signs of
eluviation, with traces of SiO2;
• humus content - up to 7%;
• horizon B - illuvial, with a higher content of fine clay,
polyhedral structural aggregates, compacted.

Leached Chernozems
Arable leached chernozem (photo: IPAPS Dimo)
• formed under mesophile steppes;
• found in the Northern part, on the peripheries of
forests in the Central part, very rarely in the South;
• occupy 315 thousands ha (17%);
• mollic profile;
• carbonates leached down the profile;
• effervescence - lower limit of B horizon/BC;
• humiferous profile – 100-120 cm;
• humus content – up to 6%;
• well developed soil structure.
Mesophile steppes (photo: acad. Ursu A.)

Typical Chernozems
(a) typical chernozem in natural conditions under Stipa capillata L. steppe,
(b) arable typical chernozem (dr. Ciolacu Tatiana)
(b)(a)
• were formed under grass
steppe on eluvial-deluvial
rocks;
• interfluvial plateaus, river
terraces and slopes;
• occupy 155 thousands ha
(8,4%);
• a very deep humus profile,
usually >1 m;
• high humus content in
horizon A (about 6,5%);
• humus content reduces
gradually down the profile;
• very good soil structure,

Ordinary Chernozems
Arable ordinary chernozem (photos Prof. Cerbari V.)
• were formed under the xerophyte steppes with
Stipa capillata L. and Festuca L. communities;
• lower portions of interfluvial plateaus, river slopes
and terraces;
• occupy 370 thousand ha (20%);
• a lower humus content - up to 5%;
• carbonates - lower part of A horizon;
• Soil structure - well pronounced, grainy&small
aggregates, but lower water resistance.

Calcareous Chernozems
(a) Calcareous Chernozem and (b) the lower part of soil profile
(photos IPAPS Dimo)
a b
• were formed under the
xerophyte steppes;
• southern part of the country
on the plains and gentle
slopes and the terraces of
the Dniester River and the
small rivers in the Central
and Northern part of the
republic.
• occupy 548 thousand ha
(29,6%);
• the lowest humus content -
about 3%;
• soil structure is less stable;
• carbonates - at the soil
surface;

Vertic Chernozems
Vertic chernozem (acad. Ursu A.)
• small areas in different parts of the country, on
interfluvial plateaus and upper parts of gentle
slopes, mainly along the periphery of the Codrii
Region and on the Nistru Upland;
• occupy about 13.6 thousands ha (0.4%);
• formed on Neogene silty clays;
• very fine soil texture;
• absence of soil structure;
• high shrink-swell capacity;
• humus content about 5%.

Grey forest soils
Subtypes: albic, typical, mollic, vertic
• were formed under the oak forests; slopes of
“Codrii” forest hills in the range of 140-300 m
altitude;
• occupy about 124 thousand ha (6.7%);
• differentiation of the profile in A - eluvial and
B - iluvial horizons, both after color and
texture.
Albic grey forest soil (photos IPAPS Dimo)

Cernoziomoid soils
Subtypes: leached, typical
Typical chernoziomoid soil (acad. Ursu A.)
• occupy about 68 thousands ha (3.7%);
• surplus of moisture in the lower part of
the profile;
• mollic and humus-rich A horizon;
• humus content decreases slowly;
• soil structure of horizon A is grainy, well-
pronounced with good water resistance.
• horizon B - hydric

Alluvial soils
• the youngest soils in Moldova;
• were formed on recent alluvial deposits;
• very different in terms of morphological
structure, texture;
• can have characters of salinization,
solonetzization, gleyzation.
Alluvial mollic soil (photos acad. Ursu A.)
Subtypes: mollic, stratified, hydric,
peaty and vertic.

Deluvial soils
• were formed at the base of the
slopes and in valleys due to
transportation of soil particles
through water;
• layers of material more or less
transformed;
• deep, humiferous and well
structured.
Subtypes: mollic, ochric
Deluvial mollic soil (photos acad. Ursu A.)

Rendzina soils
Subtypes: leached, calcareous
• occupy about 1533 ha (0,08%);
• formed on limestone parent rock;
• calciphyte vegetation;
• thin soils (40-50 cm);
• sharp boundary with the underlying rock;
• humus-rich;
• structured, but often skeletal, with
limestone fragments.
Leached rendzina soil (photos acad. Ursu A.)

Grey forest soils - are suitable for all crops, especially for apple
orchards, potatoes, vegetables, sugar beet.
Typical and leached chernozems - are suitable for apple and pear
orchards, walnut, vegetables, sugar beet, soybean.
Ordinary and calcareous chernozems - are suitable for
vineyeards and apricot, peach and orchards, irrigated vegetable
crops.
Alluvial soils - are suitable for all crops, especially for vegetables
at irrigation.
Landuse of Black soils in the Republic of Moldova

Web portal of soils of the Republic of Moldova
(Institute of Pedology, Agrochemistry and Soil Protection “Nicolae Dimo”)
Landuse of Black soils in the Republic of Moldova

LD-Bugeac
LD-Mircești
LD-Purcari

Nr. parcelei – soi altoi/portaltoi
1 - Feteasca Neagră (ob)/ BxR SO4 cl.5
2 - Rara Neagră (ob)/ BxR SO4 cl.5
3 - Merlot cl.R-3/BxR SO4 cl. 762
4 - Cabernet Sauvignon (ob.)/ BxR SO4
Parcela viticolă – soi altoi/portaltoi
5 - Rara Neagră (ob.)/BxR SO4
6 - Feteasca Neagră (ob.)/BxR SO4
7 - Cabernet-Sauvignon cl.341/Ru 110
8 - Merlot cl.181/BxR SO4 cl.5
9 - Feteasca Albă (ob,)/BxR SO4
10 - Chardonnay cl.548/BxR SO4 cl.5
Parcela viticolă – soi altoi/portaltoi
1 - Feteasca Regală/BxR SO4 cl.5
2 - Sauvignon (ob.)/BxR SO4 cl.5
3 - Rara Neagră (ob.)/BxR SO4 cl.5
4 - Feteasca Neagră (ob.)/BxR SO4
cl.5
1
2 3
4
The spatial location of geodesic pickets and vineyard parcels
Bugeac-LD
Purcari-LD
Mircești-LD

The main restrictive factors of the productive capacity of soils in Moldova
and the damage caused to the national economy
Restrictive factors
Affected area,
thousands ha
Annual losses,
thousands of US
$
Soil erosion:
- water erosion 839,7 221365
- landslides 81,0 -
Humus loss, soils with low (<3%) and very low (<2%) humus content 1037,0 18873
Soils with low and very low content of mobile phosphorus 785,0 28574
Soil compaction 2183,0 39730
Periodic waterlogging 308,6 5616
Soil degradation as a result of irrigation (salinization, compaction
etc.)
12,8 699
Solonetzization of automorphic soils 25,0 1820
Landtake and sealing (annualy 1515 ha) 40,9 63801
Status of Black soils in the Republic of Moldova

Soil erosion
Soil erosion degree Eroded soils (ha)
Weak 558170
Moderate 288070
Severe 135320
Total 981536

Spatial distribution of eroded soils
Area: 136019 ha
Landslide formation
Sheet erosion
Linear erosion
Area: 867866 ha

Effect of the erosion degree on the development of autumn barley
1,8
%
Not eroded soil Weak eroded soil Moderate eroded soil
3,5
%
2,5
%

Strip cropping at the
Experimental Station of Institute of
Pedology, Agrochemistry and Soil
Protection “Nicolae Dimo”, com.
Lebedenco, Cahul district, the Republic
of Moldova

Sectoral Breakdown of the RM’s GHG Emissions in 1990 and 2010
Data source: Third National Communication of the Republic of Moldova Under the United Nations Framework Convention
on Climate Change, 2013

Humus loss
Arable typical chernozem (photo: Ciolacu Tatiana)
Arable typical chernozem (photo: Ciolacu Tatiana)

Depth,
cm
1877
steppe
1960 arable soil 2003
Profile
nr. 42
Profile
nr. 43
Arable
soil
Forest
strip
0-20 5.718 3.75 3.60 3.36 4.2
30-40 - 3.65 3.30 3.15 3.0
50-70 - 2.34 2.73 1.94 -
70-90 - 1.59 1.57 1.68 -
Case study of humus loss of typical chernozem
Data sourse: Acad. Ursu A. The monitoring case of dehumification
of typical chernozem, 2005

Humus balance in arable soils of the Republic of Moldova
0.41
0.4
0.2
-0.45
-0.37
-0.69
-0.66
-1.1
-0.9
-0.86
-0.79
-0.98
-0.97
-0.79
-1.15
-1.13
-1.05
-0.34
-1.26
-0.87
-1.03
-1.07
-0.43
-1.07
-0.71
-0.48
-0.93
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
t/ha

Global View - GSOCmap V0.8 (01/11/17)
Participants - 168 Countries

Development of the Soil Organic Carbon Stock Map for the Republic of Moldova
There are no any measured data on SOC in the country. Development of SOC map was performed using
indirect methods and digital soil map of 1:10000 scale (more than 70 ths. soil polygons). For every
polygon at subtype level there were utilized data on humus (%) according to Crupenicov I. handbook
“Statistical parameters of Moldova soil composition and proprieties”, part I, 1978. Correction
coefficients for erosion, texture and bulk density were used according to Crupenicov I. handbook
“Statistical parameters of Moldova soil composition and proprieties”, part II, 1981.
Assessment of SOC in 0-30 cm soil layer was performed using following equation:
𝑺𝑶𝑪 𝟑𝟎 =
𝑪 𝒉𝒖𝒎𝒖𝒔
𝟏,𝟕𝟒𝟐
∗ 𝑪 𝒆𝒓𝒐𝒛 ∗ 𝑪𝒕𝒆𝒙𝒕 ∗ 𝑩𝑫 ∗ 𝒉
where:
𝑆𝑂𝐶30 - Soil Organic Carbon Stock [kg/m2]
𝐶ℎ𝑢𝑚𝑢𝑠 - humus content for different soil subtypes [%]
1,724 – correction coefficient
𝐶ℎ𝑢𝑚𝑢𝑠 – correction coefficient for soil erosion degree (Table 1)
𝐶𝑡𝑒𝑥𝑡 – correction coefficient for soil texture (Table 2)
BD – bulk density [g/cm3]
h - soil depth, 30 cm

Table 1. Correction coefficient for soil erosion degree
Soil erosion 𝐶𝑒𝑟𝑜𝑧
not eroded 1
slightly eroded 0,75
moderately eroded 0,55
strongly eroded 0,4
very strongly eroded 0,3
Table 2. Correction coefficient for soil texture
Soil texture 𝐶𝑡𝑒𝑥𝑡 BD
Fine an medium clay 1 1,3
loamy clay 0,9 1,2
clayey loam 0,8 1,17
loam 0,7 1,18
sandy loam 0,6 1,24
loamy sand 0,4 1,25
Development of the Soil Organic Carbon Stock Map for the Republic of Moldova

Conservation of soil invertebrates in natural ecosystems in the Republic
of Moldova (mean values, n = 3-32)
Biomass of invertebrates 84
46,9
82,2
11,5 9,8
17,8
8,47,6
0
20
40
60
80
100
Typical
chernozem
Leached
chernozem
Gray forest soil Ordinary
chernozem
gm-2
Fallow (virgin) Arable
 The current status of the biota of agricultural
soils in the all zones of the Republic of
Moldova is characterized by the significant
reduction in the abundance, biomass and
activity in comparison with soil’s standards
that are in conditions of natural ecosystems.
 Biota of virgin and fallow soils exists in
conditions of the high supply of the organic
matter and the conservation of resources that
have been formed within the limits of the
ecosystem.
 The number of invertebrates in natural soils is
reached to 196-448 ex m-2, Lumbricidae family
– to 83-340 ex m-2, and its biomass – to 47-84
and 42-75 g m-2 accordingly.
 The soils of natural ecosystems are
characterized by a high diversity of
invertebrates. Virgin and fallow soils contain
5-12 families of invertebrates.
 Indices of the number and biomass of
invertebrates decreased in arable soils by
2.4-5.9 and 4.6-10 times respectively in
comparison with virgin and fallow soils.
Agricultural soils contain only 2-5 families of
invertebrates.
(Data source: Senicovscaea Irina, 2011, 2012, 2013)
Number of invertebrates
339,6
81,6
195,8
448
84,9
141,4
76,463,8
0
100
200
300
400
500
Typical
chernozem
Leached
chernozem
chernozem
exm-2

Microorganisms in soils of the Republic of Moldova (0-30 cm, n = 8-33)
Microbial biomass
492,5
355,8
876
415,6
244,3
288,3318,4 314,7
0
100
200
300
400
500
600
700
800
900
1000
Typical
chernozem
Leached
chernozem
chernozem
µgCg-1soil
Humus-mineralizing microorganisms
2,7
6,5
1,9
5,5
8,9
11,9
16,2
9,6
0
5
10
15
20
Typical chernozem Leached
chernozem
chernozem
CFUg-1
soil106
 The total biomass of
microorganisms in natural soils
constitutes in average 356-876 µ g
C g-1 soil in the 0-30 cm layer. It is
much greater than its abundance
in arable soils.
 A similar trend has been noticed
in the number of the heterotrophic
bacteria and fungi.
 But the number of the
humus-destroying
microorganisms and
actinomycetes is much lower than
in the soils of agricultural
ecosystems.

Enzymatic activity of fallow (virgin) and arable soils of the
Republic of Moldova (0-30 cm, n = 3-30)
Urease
5,5
8,1
12,5
8,6
3,1
4,5
3,5
1,4
0
5
10
15
Typical
chernozem
Leached
chernozem
chernozem
mgNH310g-1
soil24h-1
Dehydrogenase
2,79
2,4
2,92
2,31
1,47
1,94
1,78
0,74
0
0,5
1
1,5
2
2,5
3
3,5
4
Typical
chernozem
Leached
chernozem
chernozem
mgTPF10g-1
soil24h-1
Activities of soil enzymes in the arable soil reduced:
 urease – by 1.6-5.8 times
 dehydrogenase – by 1.5-3.2 times

Losses of microbial biomass in the ordinary chernozem depending on the degree
of erosion (0-30cm)
Degree of
erosion
Humus
content,
%
Organic
C,
%
MB*,
µg C
g-1 soil
V
(MB),
%
Losses of MB*
(0-30 cm),
kg ha-1
mean
values
confidence
intervals (P ≤0.05)
Normal profile 3.00 1.74 288.3 16.8 - -
Slightly eroded 2.81 1.63 224.6 31.6 354.9 213.6-496.2
Moderately
eroded 2.27 1.32 159.4 36.1 738.2 609.6-866.8
Severely eroded 1.63 0.95 110.0 46.3 1048.0 1025.5-1070.5
*MB – microbial biomass (Data source: Senicovscaea Irina, 2011, 2012, 2013)

Climate change
• Warmer temperatures would increase the length of the growing season, they could also increase
crop damage due to heat stress, changes in precipitation patterns, and pest problems. Impacts
would vary regionally and with the type of crop being cultivated.
• A large proportion of soils in RM’s agro-climatic zones are black soils. These soils have large
organic matter content and breakdown of Soil Organic Matter (SOM) is likely to increase with
warmer temperatures. While this breakdown will increase soil fertility in the short term (via
release of nutrients) in the longer-term soil fertility is likely to be reduced.
• The most vulnerable regions in the RM due to possible climate change will be South (the Plain of
Southern Moldova, terraces of the inferior Prut and Dniester Rivers) and partly Center (Sub-zone
II-a, the Plain of Central Moldova and Codrii region, and Sub-zone II, Terraces of the Dniester, Prut,
Raut, Prut, Bic, Botna etc. rivers).
• For agriculture in the RM, five of the identified risks are considered to be of high priority:
 increased risk of drought and water scarcity;
 increased irrigation requirements;
 soil erosion, salinization, desertification;
 increased risk of agricultural pests, diseases, weeds;
 and wheat and maize yield decrease.
2. Challenges of Black Soils in the Republic of Moldova

Adaptation measures on water conservation for agricultural purposes could include:
• Achieving optimal irrigation methods (e.g. correct timing);
• Adapting plants to future climate conditions (e.g. growing less water-intensive crops);
• Modification of crop rotation according to the natural soil water regime (that is, introduction
of a greater number of winter crops);
• Selection of proper drought-resistant crops, plant species and varieties;
• Awareness building in new technologies that address soil structure stability and soil treatment
for expanding the active layer of the root zone for enhancing water uptake;
• Introduction of mulch technology for increasing infiltration into the soil and decreasing soil
water loss by evaporation;
• Runoff reduction by agronomic practices (No till and mini till cropping systems can reduce
water runoff);
• Runoff depending on soil characteristics can also be delayed by tillage methods combined with
plants with a high root density and lush surface cover;
• Development of new complex agricultural water management programes (combining
irrigation, fishery and excess inland water management);
Climate change

National Policies:
• Program for the Conservation and Enhancement of Soil Fertility for
2011-2020, Government decision nr. 626 of 20 August 2011:
 stopping the active soil degradation on an area of 900 thousand ha;
 applying soil conservation measures and increasing soil fertility on an
area of 1.7 million hectares.
• The National Development Strategy "Moldova 2020“;
• Biological Diversity Strategy of the RM 2015-2020 and the Action Plan:
• The Environmental Strategy for 2014-2023 and the Action Plan;
• on 13 July 2016, the Moldovan Government has set up a new body - the
National Council for Sustainable Development - which will deal with the
implementation of commitments from the United Nations Agenda for
Sustainable Development 2030;
• National program for the extension of the forest vegetation areas for the
years 2014-2018;

Thank you for your attention!
The presentation was discussed and approved at the meeting of
the Soil Science Society of Moldova

Status of “Black soils” in the Republic of Moldova - Ciolacu Tatiana

Status of “Black soils” in the Republic of Moldova - Ciolacu Tatiana

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Status of “Black soils” in the Republic of Moldova - Ciolacu Tatiana