Post on 07-Aug-2020
transcript
ROMANIAN SOIL RESOURCES - “HEALTHY SOILS FOR A
HEALTHY LIFE”
Mircea MIHALACHE, Leonard ILIE, Doru Ioan MARIN
University of Agronomic Sciences and Veterinary Medicine of Bucharest 59 M r ti Blvd., District 1, Postal Code 011464, Bucharest, Romania
Corresponding author email: mihalachemircea@yahoo.com
Abstract After nearly three years of intensive consultations, 2015 has been declared the International Year of Soils by the 68th UN General Assembly (A/RES/68/232). The International Years of Soil is to be a major platform for raising awareness of the importance of soils for food security and nutrition and essential eco-system functions. Key objectives of the International Years of Soil have been identified as follows: to create full awareness of all stakeholders about the fundamental roles of soils for human life; to achieve full recognition of the prominent contributions of soils to food security and nutrition, climate change adaptation and mitigation, essential ecosystem services, poverty alleviation and sustainable development; to promote effective policies and actions for the sustainable management and protection of soil resources; to sensitize decision-makers about the need for robust investment in sustainable soil management activities, to ensure healthy soils for different land users and population groups; to catalyze initiatives in connection with the Sustainable Development Goal process and Post-2015 agenda; to advocate rapid enhancement of capacities and systems for soil information collection and monitoring at all levels (global, regional and national) (http://www.fao.org/soils-2015). Applying a proper management of the recovery and conservation of soil resources is a major goal for every nation. The development of a country depends on the production potential of own soil resources. Soil degradation is a serious problem in Europe an also in Romania. It is caused or exacerbated by human activity such as inadequate agricultural and forestry practices, industrial activities, tourism, urban and industrial expansion etc. Soil Quality Monitoring in Romania revealed a number of problems concerning land use in Romania following the manifestation of one or more limiting factors such as: moisture deficit, salinization and alkalization, soil erosion, waterlogging, reduced organic matter content soil acidity, compaction, pollution, reduced edaphic volume etc. Key words: soil resources, soil health, degradation, monitoring. INTRODUCTION Soil health has been defined as "the continued capacity of the soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain biological productivity, promote the quality of air and water environments, and maintain plant, animal, and human health". (Doran et al., 2002) The trend in soil health is the assumed change in the recent past, determined by two major pressures on the soil as they are influenced by soil management: • The physical pressures related to loss of soil
mass and structure; • the pressures on the long term chemical
well-being of the soil in terms of nutrient availability and the absence of toxicities built up in the soil.
This trend can be negative (degradation) if the soil management is not adequately counteract the (natural and management) pressures, but may also be positive and result in improvements when the applied soil management and conservation techniques and approaches are more than compensating soil deterioration. Healthy soil gives us clean air and water, bountiful crops and forests, productive rangeland, diverse wildlife, and beautiful landscapes. Soil does all this by performing five essential functions. Nutrient cycling - soil stores, moderates the release of, and cycles nutrients and other elements. During these biogeochemical processes, analogous to the water cycle, nutrients can be transformed into plant available forms, held in the soil, or even lost to air or water.
101
AgroLife Scientific Journal - Volume 4, Number 1, 2015ISSN 2285-5718; ISSN CD-ROM 2285-5726; ISSN ONLINE 2286-0126; ISSN-L 2285-5718
Water relations - soil can regulate the drainage, flow and storage of water and solutes, which includes nitrogen, phosphorus, pesticides, and other nutrients and compounds dissolved in the water. With proper functioning, soil partitions water for groundwater recharge and for use by plants and soil animals. Biodiversity and habitat - soil supports the growth of a variety of plants, animals, and soil microorganisms, usually by providing a diverse physical, chemical, and biological habitat. Filtering and buffering - soil acts as a filter to protect the quality of water, air, and other resources. Toxic compounds or excess nutrients can be degraded or otherwise made unavailable to plants and animals. Physical stability and support - soil has the ability to maintain its porous structure to allow passage of air and water, withstand erosive forces, and provide a medium for plant roots. Soils also provide anchoring support for human structures and protect archeological treasures. This paper presents the main limiting factors of soil resources in Romania and and their influence on the physico-chemical soils characteristics. Soil degradation is a serious problem in Europe an also in Romania. It is caused or exacerbated by human activity such as inadequate agricultural and forestry practices, industrial activities, tourism, urban and industrial expansion etc. Damage to Europe’s soils from modern human activities is increasing and leads to irreversible losses due to soil erosion, local and diffuse contamination and the sealing of soil surfaces. Population growth coupled with urbanization is putting soils under pressure, while agricultural intensification is making soils more prone to erosion. Sealing of soil surfaces due to an increased urbanization and new infrastructures is the main cause of soil degradation in the most industrialized and populated countries of western and northern Europe. Sustainable management of soil as a natural resource, together with air and water, is one of the environmental challenges and priorities in the 5th Environmental Action Programme. Soil Quality Monitoring in Romania revealed a number of problems concerning land use in Romania following the manifestation of one or more limiting factors such as: moisture deficit,
salinization and alkalization, soil erosion, waterlogging, reduced organic matter content soil acidity, compaction, pollution, reduced edaphic volume etc. Soil degradation processes have a direct impact on water and air quality, biodiversity and climate change. The degradation of soil resources affect health and safety of agricultural and food products (Dumitru et al., 2000). The adoption of the EU Thematic Strategy for Soil Protection by the European Commission on 22 September 2006 has given formal recognition of the severity of the soil and land degradation processes within the European Union and its bordering countries. Soil degradation processes are driven or exacerbated by human activity. Climate change, together with individual extreme weather events, which are becoming more frequent, will also have negative effects on soil. Soil degradation processes occurring in the European Union include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. RESULTS AND DISCUSSIONS From the perspective of crop production, soil fertility at its core is determined by soil life. Conventional agronomy as it is taught in most formal university settings does not prioritize soil life as the central force, and it could be argued that this is causal in the drastic decrease in agricultural soil fertility worldwide. Conventional fertility and management protocols are in many ways very destructive to soil life, and due to this have effected desertification, erosion, pollution of waterways, aquifers, and the environment in general. Romania's soil resources are shown in Figure 1. In recent years arable farmland harnessed in Romania is about 8 million ha. If in 10 years ago in Romania's arable land was used by 9.4 million ha, this has dropped significantly in recent years. The significant decrease in arable land used is added to a number of limiting factors that can influence the level of agricultural yield.
102
Figure 1 Drought isreceives awhether atmPeriods oenvironmeand social Moisture dhectares, oand southresources iChernozemHaplic Luv
Photo 1. A
26
0
1000
2000
3000
4000
5000
6000
7000th
ousa
nd h
a
. Distribution
s an extenda deficiencmospheric,
of droughtental, agricuconsequenc
deficiency moccurs moreh-eastern pin these are
ms, Arenosovisols (Phot
Areas with mo
605
6030
3825
20
n of soil classe
ded period cy in its surface or gs can havultural, heaces. manifests are pronouncepart of Reas are theols, Fluvisoto 1).
oisture deficit
6060
740 89012
es in Romania
when a regwater suppground wateve significalth, econo
round 7 milled in the soRomania. S
Kastanozeols and part
from Romani
230780
210 5
a
gion ply, er. cant
omic
lion outh Soil
ems, t of
ia
WasoiparWarainwadrasub(FiSoiproa gsoiredthuencthebuidraWafrogaszonconWhare-
-
-
-
-
F
830
aterloggingl typesrticularly aterlogging nfall, poortertables, o
ainage (acrbsurface drgure 2). il strengthogressively greatly increl structure
duces the amus seriouslycouraging ae expense ild up of salained irrigataterlogging m reachingses and comne due tonditions. here soil dre seen: plants are slost due to of aeration)improved weeds (doccouch etc.)pastures butilisation isoils becomsurface; responses t
Figure 2. Distr
0
100
200
300
400
500
600
thou
sand
ha
g is a comm(Gleysols,
in the wmay be du
r irrigation or a combinross the rainage (do
h decreaseswetter
eased poten(Photo 2)
mount of oxy inhibitinanaerobic soof aerobic lt is also motion pasture
prevents ag the root
mpounds areo the ana
rainage is p
stunted anddenitrificat
); pasture placks, smartw;
become fous reduced;
me pugged a
o applied fe
ribution soil tyclasse
Gleysols
585
mon problem, Stagnic winter an
ue to periodn managemnation of ppaddock)
own the so
s as the r, resulntial for dam. A waterl
xygen in theng plant goil micro-orc micro-orgore likely uns.
air and mants. Also une produced aerobic (no
poor, numer
d yellow as tion (caused
ants are reweed, rush
uled with
and water p
ertiliser are
ype from Hydes
Stagnic luvisols
100
m on manyluvisols)
nd spring.ds of heavy
ment, risingoor surfaceand poor
oil profile)
soil getsting in
mage to thelogged soile root zone,growth andrganisms atganisms. Ander poorly
ny nutrientsnfavourablein the root
o oxygen)
rous effects
nitrogen isd by a lack
eplaced byes, sedges,
mud and
onds on the
poor etc.
dromorphic
s
y )
y g e r )
s n e l ,
d t
A y
s e t )
s
s k
y ,
d
e
103
Photo 2. M
Soil erosiover geolothat is essplace. Witconcerns acceleratedbeen signiactivity. Soproblem thBy removireduces soshallow, mnatural farmEven whetopsoil inevertheleserosion isdevelopmeeroded chafarmland. Soil erosioslopes witThe surfacis around 6The soil reexample dbelow theblocking rinundating
Moisture excesra
on is a naogical time, ential for sth respect t
about erd erosion, wficantly incoil erosion
hroughout Eing the mo
oil productimay lead tomland (Pho
ere soil deps often ss potentials commonent of temannels or g
on occurs th differentce area with6 million heemoved by during a le eroded roadways o
g buildings.
ss from the grainfall
atural procand indeed
soil formatito soil degrosion arewhere the ncreased moby water is
Europe. ost fertile tovity and, wo an irreve
oto 3). pth is good
not conly very dam
nly associamporary orgullies that
in soils lot degrees h soil erosioectares.
runoff fromarge stormareas, in
or drainage
ound water an
cess, occurrd it is a procion in the f
gradation, me related natural rate stly by hums a widespr
opsoil, eroswhere soils ersible loss
d, loss of spicuous
maging. Sevated with r permanen
can fragm
cated on hof inclination in Roma
m the land, m, accumula
severe cachannels
nd
ring cess first
most to
has man read
sion are
s of
the but
vere the
ntly ment
hilly tion. ania
for ates ases and
SantexretaholSoiincimpproWi230sou
Fi
hd
h
Photo 3
ndy soils arxtured until ain few nulding capaciil managem
crease in thproving oductivity. nd erosion0,000 ha, uthern Olten
igure 3. Distri
0
500
1000
1500
2000
2500
Lept
thou
sand
ha
3. Soil erosion
re those tha50 cm de
utrients andity (Figure 3
ment practihe fine frasoil prop
occurs ovespecially
nia (175,000
bution type so
tosols Regosols
95 100
n from hilly ar
at are generepth and cod have a 3). ces which action are perties a
ver an areay on Are0 ha) (Photo
oils from Prot
s Arenosols Fl
230
reas
rally coarseonsequentlylow water
lead to anhelpful in
and crop
of aroundenosols ino 4).
isols classes
uvisols
2180
e y r
n n p
d n
104
Ph Structuraldense, somaggregatedand exposdevelop wout after rstriking soacross soisoil particinto and bsurface to soaking intdries out, iStructural thick as twmore compthe soil imloose and their strengSoil crustinand chemiliving comalgae, andthat bind chemical csalt contenA surface problematiexchange bcan also in
hoto 4. Arenos
l soil crumewhat cod soil particled soils (P
when a sealerainfall or ioil aggregl breaks agles. Fine s
block surfacseal over ato the soil. At crusts ovecrusts rang
wo inches. pact, hard a
mmediately friable. Cr
gth, or air-dng is also aical factorsmmunity od moss grow
the soil tcrust can dent.
crust indiical seedbbetween thndicate that
sols from Olte
usts are rontinuous lles on the s
Photo 5). Sted-over soiirrigation. Wates and wggregates isoil particlece pores ca
and preventiAs the mud
er. ge from a fe
A surface and brittle beneath it,
rusts can bedry rupture rassociated w. A biolog
of lichen, wing on thtogether. Aevelop on s
cates poor bed, and e soil and a soil has
nia area
elatively thayers of nurface of titructural crul surface dWater dropwater flowinto individes wash, seausing the ing water fr
ddy soil surf
ew tenths tocrust is mwhen dry twhich may
e describedresistance. with biolog
gical crust icyanobacte
he soil surfA precipitasoils with h
infiltrationreduced
atmospherea high sodi
thin, non-lled usts
dries plets wing dual ettle soil
from face
o as much than y be d by
gical is a eria, face
ated, high
n, a air
e. It ium
conweOndisfacThimilPra•
•
SalexcsoipotsulsoddissecsalinattheSecintepraandSodexcincliquNaion(alksoi
ntent that intted by rain
n loamy texpersion of
ctor for agris phenomellion hectareactices that lHarvesting,removing pto leave theperiod of tiSoil disturbmatter, soiresult in ve
linization icessive incrl. The acctassium, maphate, carb
dium chlortinction can
condary sainization intural procese parent condary saerventions actices, e.gd/or insufficdification ichangeable creased. Na+
uid phasesHCO3 or N
ns in the kalization), l absorption
ncreases soinfall or irrigature soils instructural
icultural prnon can occes. lead to soil , burning, bplant residue soil surfacme, and
bing activitil structure ry smooth s
Photo 5. So
s the procrease of watcumulated sagnesium abonate and ride and sn be made alinization
nvolves salt sses due to material
alinization isuch as in. with saltcient drainags the prosodium (Na+ accumulats of the
Na2CO3 salthighly alor as exch
n complex (
il dispersionation. n the southaggregates
roduction iscur in appro
crusting incburying, or
ues and muce bare for a
es that destand aggreg
seedbeds.
oil crusts
cess that leater-soluble salts includand calciumd bicarbonasodium subetween pprocesses
accumulatia high saltor in gris caused
nappropriatet-rich irrigaage (Photo 6ocess by a) content o
ates in the ssoil as
ts (salt efflolkaline soihangeable (ESP).
n when it is
h due to thea limiting
s the crust.oximately 2
clude: r otherwiselches so asan extended
roy organicgation, and
eads to ansalts in the
de sodium,m, chloride,ate (mainlyulphate). A
rimary and. Primaryion throught content ofroundwater.by human
e irrigationation water6). which the
of the soil issolid and/orcrystallisedoresces), asil solutionions in the
s
e g
2
e s d
c d
n e , ,
y A d y h f
n n r
e s r d s n e
105
Salinizatiosodificatioareas wevapotranscharacterissalts whichsurface laywaters drSalinity isdegradatioRomania ssalinizationSolonetz aarea of app
Figure 4.
Acid soilsless than associated (Aluminum(MolybdenconditionsSoil pH including fertiliser us
0
20
40
60
80
100
120
140
160
thou
sand
ha
on, also knn, is often where lspiration rstics impedeh subseque
yers. Irrigatramatically s one of thn processes
soils affecten and alkaand other sproximately
Photo 6. S
Distribution c
s are those 5.5 for mo
with am) as num) and . is influensoil type,
se and farm
Solonchaks
65
nown as aassociated
low rairates or e the washently build-ion with hi
worsens he most ws on the Earted by varioualization (Ssoils subtypy 600,000 ha
Soil salinizatio
soil type fromclasses
that have
st of the ya number
well other pla
nced by morganic m
ming practice
Solon
alkalization with irriga
nfall, hsoil textu
hing out of -up in the gh salt conthe probl
widespread th. us processeolonchaks pes) coversa (Figure 4)
on
m Halomorphic
a pH valueyear. They
of toxicias deficienc
ant restrict
many factmatter, rainfes.
netz
145
or ated high ural the soil
ntent lem. soil
s of and
s an ).
c
e of are
ities cies ting
tors, fall,
SoithefarmaciwomaacinitrThsoi•
•
•
•
•
Pro•
•
•
•
SupabiSoimilhecof incProreathe201
il acidificate soil pH deming pracdification. S
ords, a highatter contedification, rogen fertilie major prl acidificatiThe additiomatter, whacid. The removanimal prolevels ofpotassium. bases (as oremoval incThe leachi(magnesiumcalcium) frainfall. The leachiroot zone. The applicaas those ththat contain
oblems that Aluminiumplants. Decreased phosphorusmolybdenucalcium to Decreased microbes anutrients. Suppressionaffects leguppression oility to take il acidity ollion hectarctares are sinadequate
crease of soiolonged useaction can de horizon s10; 2012) (F
ion is a natecreases ovctices incSoils with ah sand content are m
particularlyisers are appocesses thaon are: on and acc
hich creates
al from theducts that t
f calciumThese thr
opposed to creases aciding of them, potassiufrom the s
ng of nitra
ation of acidhat contain n nitrogen acan occur i
m and ma
availabis, potam, magnplants.
biologicaand thus r
n of rhizoume nodulatof root group water an
occurs overres of whitrongly affecultivation
il acidity in e of nitrogeecrease soil
surface (MiFigure 5).
tural procesver time. Mcrease thea light textutent) and lomost suscy if high plied. at increase
cumulation s humic ac
e paddock otypically co
m, magnesree elemenacids), and
dity. e exchangeum and soil caused
ate nitrogen
difying fertielemental
as ammoniuin acid soilsanganese t
ility of tassium, nesium, b
al activityreduced re
obia bactetion. owth and nd nutrientsr an area ich about fected. Laten technologthe horizon
en fertilizerl reaction eihalache et
ss in whichMany of our
rate ofure (in otherow organiceptible to
levels of
the rate of
of organicid, a weak
of plant andontain highsium andnts are alld thus their
eable basesparticularlyd by high
n from the
ilisers, suchsulphur or
m or urea. s include: toxicity to
nitrogen,sulphur,
oron and
y of soilecycling of
eria, which
the plant'ss. about of 31.8 millionly, because
gies was ann surface. s with acidspecially in
al., 2009;
h r f r c o f
f
c k
d h d l r
s y h
e
h r
o
, ,
d
l f
h
s
3 n e n
d n ;
106
Figure 5. C
Incorporatisoil layeramelioratioapplied asinfertility, magnesiumpH of acifixing banitrogen fixNitrogen and organincreases Although lpH and amsoil, limingstructure. Soil compdistributionquantify thdensity. Assoil, the buhigher penaturally hbulk densitExcessive and therefoby roots. Tability to tstandpoint effect of sstorage maeffect of soIn dry yestunted, ddecreased and well-poccur. Soilsoil aerat
012345678
0-20cm
20c
6.82 6
hange Haplic Dom
ion of limer is an on of acid s a preven
and to m to deficieid soil, thuacteria becxation incremineralizat
nic matter when lime lime is primmend toxicig has also b
paction chn, and soihe change is the pore sulk density rcentage o
have more ty than sandsoil compacore limits thThis, in turnake up nutr
of crop soil compaay be moroil compactears, soil drought sroot growlaced fertilil compactiotion. This
0-40cm
40-60cm
60-80cm
6.95 7.15 7.181990
Luvosol reacmneasc
e into the up
effective soils. Lim
ntative treatsupply
nt soils. Limus the actiocomes unieases. tion from p
has beenis applied
marily appliities associbeen used t
hanges porl strength. is by measpace is decris increase
of clay anpore space,dier soils. ction impedhe amount on, can decrerients and wproductionction on we serious tion on root compactiontressed pl
wth. Withouizers, yield on in wet ys results
0-20cm
20-cm
8
5.4 5
tion from Mo
pper cultivamethod
e can alsotment for calcium
ming raises on of nitroinhibited
plant residn reported d to acid sed to raise ated with ato improve
re space sOne way
uring the breased withd. Soils wit
nd silt, wh, have a lo
des root groof soil exploease the pla
water. From n, the advewater flow than the digrowth.
n can leadlants due ut timely rareductions w
years decreain increa
-40m
40-60cm
60-80cm
5.76.52 6.63
2013
ara
able for
o be soil and the
ogen and
dues to
soil. soil acid soil
size, y to bulk hin a th a hich wer
wth ored ant's the erse and rect
d to to
ains will ases ased
denatmSoidegdisporis iCocapacccantheSomcemsubstroso loaIn top(Phfortyrplopersoiof tloocumcom
nitrificationmosphere). il compacgradation rtortion of trosity and pincreased anmpaction
pacity andcelerating rn be initiatee passage ofme soils armented or hbsoil. Soils ong to resisweak that t
ads. arable lan
psoil and hoto 7). A rmation of aes driving
oughing (armeable for l below andthe subsoil.
osened anmulative anmpacted lay
Photo 7. S
(loss of n
tion is aresulting ihe soil whe
permeabilitynd soil struccan reduc
d increaseun-off. The
ed by wheelf animals. re naturallyhave a thin can vary fr
st all likely they are com
nd with ansubsoil comfeature of ca pan-layer,
directly oabove). Th
roots, wated is a bottle Unlike top
nnually, cnd over ti
yer is create
Soil compactio
nitrate-nitro
a form oin densificere biologicy are reducecture partlyce water e erosion e compactils, tracks, ro
y compacten topsoil layfrom being applied loampacted by
nnual plougmpaction icompacted , caused by
on the subhe pan-layeer and oxygeneck for th
psoil, the sucompaction ime, a ho
ed.
on (Haplic Lu
ogen to the
f physicalcation andcal activity,ed, strengthy destroyed.
infiltrationrisk by
ion processollers or by
ed, stronglyyer on rocksufficiently
ads to beingy even light
ghing, bothis possiblesoils is the
y the tractorsoil duringer is less
gen than thehe function
ubsoil is notbecomes
mogeneous
uvosol)
e
l d ,
h
n y s y
y k y g t
h e e r g s e n t s s
107
The loss of macro porosity and pore continuity reduces strongly the ability of the soil to conduct water and air. • Reduced infiltration capacity results in
surface run-off, leading eventually to flooding, erosion and transport of nutrients and agrochemicals to open water.
• A poor aeration of the soil reduces plant growth and induces loss of soil nitrogen and production of greenhouse gases through denitrification in anaerobic sites.
Soil compaction occurs in most soils cultivated on an area around of 6.5 million hectares. Edaphic volume (Ve, fractions of unity). This is an index of the overall profile showing the fine material content without skeleton, useful to plants. It is expressed in percentages or fractions of units compared to 100 cm thick. For soils with thickness greater than 1 m, the values of the edaphic volume are higher than one. Edaphic volume reduced is recorded at skeletal soils with different percentages of skeleton on soil profile which is a limiting factor for the development of the root system of plants (Photo 8).
Photo 8. Low edaphic volume
For agricultural plots, the plots with large edaphic volume (35.5%) are predominant, followed by soils with very large (23.7%) and medium (20.3%) edaphic volume.
As regarding the soil types, the highest values are characteristic to Luvisols (1.11 fractions of unity), Phaeozems (1.10), Luvisols (1.07), Chernozems (0.92), while the lowest average values characterize Leptosols (0.19), Andosols (0.37), Rendzic Leptosols (0.37) and Entic Podzols (0.45). Soil organic carbon, the major component of soil organic matter, is extremely important in all soil processes. Organic material in the soil is essentially derived from residual plant and animal material, synthesised by microbes and decomposed under the influence of temperature, moisture and ambient soil conditions. The annual rate of loss of organic matter can vary greatly, depending on cultivation practices, the type of plant/crop cover, drainage status of the soil and weather conditions. There are two groups of factors that influence inherent organic matter content: natural factors (climate, soil parent material, land cover and/or vegetation and topography), and human-induced factors (land use, management and degradation). Organic matter exerts numerous positive effects on soil physical and chemical properties, as well as the soil’s capacity to provide regulatory ecosystem services (Brady et al., 1999). Particularly, the presence of organic matter is regarded as being critical for soil function and soil quality. The positive impacts of organic matter result from a number of complex, interactive edaphic factors; a non-exhaustive list of organic maters's effects on soil functioning includes improvements related to soil structure, aggregation, water retention, soil biodiversity, absorption and retention of pollutants, buffering capacity, and the cycling and storage of plant nutrients. Soil organic matter increases soil fertility by providing cation exchange sites and acting as reserve of plant nutrients, especially nitrogen, phosphorus, and sulfur, along with micronutrients, which are slowly released upon organic matter mineralization. As such, there is a significant correlation between soil organic matter content and soil fertility. The decrease in soil humus content recorded in most soils cultivated and low content in nitrogen, phosphorus and potassium of soils
108
with a direct influence on the yields obtained (Photo 9).
Photo 9. Low organic matter content
Soils containing organic matter have a better structure that improves water infiltration, and reduces the soil’s susceptibility to compaction, erosion, desertification and landslides. Soil contamination is the occurrence of pollutants in soil above a certain level causing a deterioration or loss of one or more soil functions. Also, soil contamination can be considered as the presence of man-made chemicals or other alteration in the natural soil environment. This type of contamination typically arises from the rupture of underground storage tanks, application of pesticides, percolation of contaminated surface water to subsurface strata, leaching of wastes from landfills or direct discharge of industrial wastes to the soil. The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead and other heavy metals. The occurrence of this phenomenon is correlated with the degree of industrialization and intensity of chemical usage.
CONCLUSIONS Soil resources from Romania in recent years an increase on the limiting factors for agricultural yield, which requires conservation measures of soils. Decreasing soil fertility with repercussions on the health and quality of agricultural yield should be a warning to limit soil degradation and rehabilitate them. Changing production technologies using high performance machines require extensive research to pursue their long-term effects on physical, chemical and biological properties of soils. A priority of the need to represent farmers' awareness about the decline of soil production potential. Government involvement in the adoption of measures for the recovery of soils in areas affected by one or more limiting factors. Develop a legislative framework to protect soil resources. Application good agricultural practices code by farmers for soil conservation. The total costs of soil degradation that could be assessed for erosion, organic matter decline, salinization, landslides and contamination on the basis of available data, would be up to 38€ billion annually for EU25. If we want a healthy life we need healthy soils which implies a change of soil resources exploitation. REFERENCES Brady N.C., Weil R.R., 1999. The nature and properties
of soils. Prentice Hall, Inc., Upper Saddle River, NJ. Florea N., 2003. Degradarea, protec ia i ameliorarea
solurilor i a terenurilor. Bucure ti. Dumitru M. and al., 2000. Soil Quality Monitoring in
Romania, Ed. GNP, Bucharest. Doran J., Stamatiadis S., Haberern J., 2002. Soil health
as an indicator of sustainable management. Publication: Publications from USDA-ARS/UNL Faculty.
Simota C., 2014. Solul i siguran a alimentar . Simpozion ASAS, Ziua solului, 5 decembrie, 2014.
Mihalache M., Ilie L., 2008. Pedologie - solurile României. Ed. Dominor, Bucure ti.
Mihalache M., Ilie L., Marin D.I., 2009. Research concerning the effect of management systems on physical and chemical properties of reddish preluvosoil from Moara Domneasca experimental field. The International Scientific Conference -
109
„Durable agriculture - Agriculture of the future”, 20-21 november, University of Craiova, p. 428-432.
Mihalache M., Ilie L., Marin D.I., 2010. Research concerning the evolution of physical and chemical properties of reddish preluvosoil from Moara Domneasc . Scientific Papers, USAMV Bucharest, Series A, Vol. LIII, p. 61-66.
Mihalache M., Ilie L., Marin D.I., 2012. Research concerning evolution on physico-chemical properties of reddish preluvosoil from Moara Domneasc experimental field. Analele Universit ii din Craiova, Vol. XLII-2012/1, ISSN 1841-8317, p. 354-359.
Tóth G., Adhikari K., Várallyay Gy., Tóth T., Bódis K. and Stolbovoy V., 2008. Updated Map of Salt Affected Soils in the European Union. In. Tóth, G., Montanarella, L. and Rusco, E. (eds.) 2008. Threats to Soil Quality in Europe EUR 23438 EN 151 pp Luxembourg: Office for Official Publications of the European Communities, p. 65-77.
***Climate and Land Degradation. Editors: Mannava V. K. Sivakumar, Ndegwa Ndiang’ui. ISBN: 978-3-540-72437-7 (Print) 978-3-540-72438-4 (Online).
***http://www.fao.org/soils-2015/about/en/. ***http://eusoils.jrc.ec.europa.eu/.
110