IL COMPORTAMENTO IDROLOGICO DEI SUOLISUOLI NELLA … · Tech. Rep. Soil and Contaminant Hydrology...

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ILIL COMPORTAMENTOCOMPORTAMENTO IDROLOGICOIDROLOGICO DEIDEISUOLISUOLI NELLANELLA VALUTAZIONEVALUTAZIONE DELLADELLAQUALITÀQUALITÀ DIDI RISORSERISORSE IDRICHEIDRICHE

RIUNIONE GRUSI

ROMA 10 GENNAIO 2012

QUALITÀQUALITÀ DIDI RISORSERISORSE IDRICHEIDRICHEMARGINALIMARGINALI PERPERL'USOL'USO IRRIGUOIRRIGUO

Antonio Coppola e Vincenzo Comegna

Università della Basilicata

Nicola Lamaddalena

Istituto Agronomico Mediterraneo Bari

Global distribution of salt-affected soils (after Szabolcs 1985)

California (san Joaquin Valley), Argentina, Egitto, India, Pakistan, Siria, Iran, Cina

Distribuzione delle precipitazioni in Italia - valori medi in mm nel periodo 1950-2000.

Source Lopez and Vurro, 2006

Distribuzione di suoli salinizzati in Italia.

Source APAT (ISPRA), 2007.

Distribuzione delle precipitazioni in Italia - valori medi in mm nel periodo 1950-2000.

EC (µS cm-1) degli acquiferi pugliesi.

LAND USE regione Puglia.

Il comportamento idrologico dei suoli nella valutazione

delle acque reflue per l’irrigazione

PPAARRAAMM EETTRRII CCHHII MM II CCOO--FFII SSII CCII PH Ferro Grassi e oli animali/vegetali SAR Manganese Oli minerali Materiali grossolani Mercurio Fenoli totali Solidi sospesi totali Nichel Pentaclorofenolo BOD Piombo Aldeidi totali COD Rame Solventi clorurati Fosforo totale Selenio Bromodiclorometano Azoto totale Stagno Cloroformio Azoto ammoniacale Tallio Solventi organici aromatici totali Cond. Elettrica Vanadio Benzene Alluminio Zinco Benzopirene Arsenico Cianuri Totali Solventi organici azotati Bario Solfuri Tensioattivi totali Bario Solfuri Tensioattivi totali Berillio SolfitSolfatii Pesticidi clorurati Boro Cloro attivo Pesticidi fosforati Cadmio Cloruri Altri pesticidi totali Cobalto Fluoruri Cromo totale Cromo VI PPAARRAAMM EETTRRII MM II CCRROOBBII OOLL OOGGII CCII Escherichia coli Salmonella Uova elminti

The D.M. 185/2003 identifies – in addition to the normal control parameters (pH, TDS, COD, BOD5), - the limits for surfactants, organic and inorganic micro-pollutants, boron, some metals and the SAR (Sodium Adsorption Ratio), biocides and pesticides. The The limits concerning the microbiologic quality (limits concerning the microbiologic quality (E. Coli, E. Coli, SalmonellaeSalmonellae) are particularly precautionary () are particularly precautionary (E. ColiE. Coli ≤ ≤ 10CFU/100ml on 80% of tested samples; 10CFU/100ml on 80% of tested samples; SalmonellaeSalmonellae= absent)= absent)to minimize the risk of infection diffusion. 54 total parameters are 54 total parameters are envisaged, 20% of which should fall within the drinking water envisaged, 20% of which should fall within the drinking water envisaged, 20% of which should fall within the drinking water envisaged, 20% of which should fall within the drinking water limits.limits. Refinement costs are in this case elevated and can be incurred only in the case of large-sized plants. Such restrictive limits seem to be in contradiction with the quality of surface water bodies (those currently used to divert water for irrigation) that are characterized, all over the national territory, by concentration levels that are far above the limits set by the DM 185/2003 (till two to three orders of magnitude higher); Escherichia Coli values of some Escherichia Coli values of some thousand CFU are most likely in most surface water bodies thousand CFU are most likely in most surface water bodies whose water is used for irrigation.whose water is used for irrigation.

Degree of compliance of treatment plants – regional detail (2007).Source: ISPRA, 2007

Gli approcci normativi in Italia ed in altri Paesi europei, pur fornendo dettagliate linee guida per il monitoraggio degli effluenti all’uscita dai trattamenti di depurazione, hanno il loro principale limite nella pressoché totale sottovalutazione degli aspetti connessi al monitoraggio dei suoli sottoposti ad irrigazione con le acque reflue.

ART. 1 comma 2. (DM 185/2003)

Il riutilizzo deve avvenire in condizioni di sicurezza ambientale, evitando

alterazioni agli ecosistemi, al suoloed alle colture, nonché rischi igienico-sanitari per la popolazione esposta….

Corpo idrico recettore SI

Suolo?? NO

Wastewater Irrigation: The State of Play

Andrew J. Hamilton,* Frank Stagnitti, Xianzhe Xiong, Simone L. Kreidl, Kurt K. Benke, and Peta Maher

Vadose Zone J. 6:823–840 doi:10.2136/vzj2007.0026

The following were identified as areas requiring greater understanding for the long-term sustainability of wastewater irrigation:

(i) accumulation of bioavailable forms of heavy metals in soils,

(ii) environmental fate of organics in wastewater-irrigated soils, (ii) environmental fate of organics in wastewater-irrigated soils,

(iii) microbiological contamination risks for aquifers and surface waters,

(iv) transfer of chemical contaminants from soil to plants,

(v) risk models for helminthes infections (pertinent to developing nations),

(vi) ……

Soil Hydrological Behaviour VariabilitySoil Hydrological Behaviour Variability

Proprieta` Proprieta` idraulicheidrauliche

TRASPORTO TRASPORTO

Comportamento idrologico dei suoliComportamento idrologico dei suoli

Proprieta` Proprieta` idrodispersiveidrodispersive

MOTO MOTO DELL`ACQUADELL`ACQUA

TRASPORTO TRASPORTO DEI SOLUTIDEI SOLUTI

Proprieta` Proprieta` chemiodinamichechemiodinamiche

EQUAZIONE DI RICHARDS (unidimensionale)

( ) ( )z

zt ∂∂−

∂∂

∂∂=

∂∂ ϕϕϕθ

- S(z,t)

EQUAZIONE CONVEZIONE -DISPERSIONE

θγθµθθρ +−

−∂∂

∂∂=

∂∂

rr cqcx

EQUAZIONE CONVEZIONE -DISPERSIONE(unidimensionale)

Coppola, A., Randazzo, L., 2006. A MathLab code for the transport of water and solutes in unsaturated soils with vegetation. Tech. Rep. Soil and Contaminant Hydrology Laboratory, Dept. DITEC University of Basilicata.

FLUMENDOSA+ MULARGIA + FLUMINEDDU - ALTO FLUMENDOSA BASIN Runoff historical series

22-23 32-33 42-43 52-53 62-63 72-73 82-83 92-93 02-03

Hydrological years

Yearly runoff Mobile average 5 yearsGeneral average Mean value until 1975Mean value from 1975 Mean value from 1986

1999/2000

Fig. 1 – Serie storica dei deflussi annui nel bacino del medio Flumendosa

9 8 . 4

2 8 9 . 7

4 1 0 . 1

4 5 0M

P re s e n t re q u i r e m e n ts

E ffe c t i v e ly d i s tr i b u te d v o lu m e

M u n ic i p a l A g r i c u lt u r a l I n d u s t r i a l T o t a lr e q u i r e m e n t s

R e q u ir e m e n ts

Fig. 2 – Richieste e disponibilità nel sistema idraulico Flumendosa - Campidano

8000 ha

DISTRETTO DI ELMAS:1. Suoli derivati da sedimenti

marnoso arenacei del Miocene.

Profilo tipo P1

2. Suoli derivati da alluvioni

conglomeratiche del Quaternario

antico con presenza di orizzonti

carbonatici

Profilo tipo P2

DISTRETTO DI S. SPERATE:3. Suoli derivati da alluvioni

conglomeratiche del Quaternario

antico privi di orizzonti carbonatici

Profilo tipo P3

4. Suoli derivati da alluvioni

conglomeratiche del Quaternario recente

in fase sabbiosa

Profilo tipo P4

DISTRETTO DI QUARTU SANT’ ELENA:5. Suoli derivati da alluvioni conglomeratiche del Quaternario recente in fase

argillosa

Profilo tipo P5

sand silt clay o.m. CEC Na K Ca Mg

horizon z (cm)

Profile P1Ap 0-40 60.33 18.13 21.53 0.88 17.43 0.16 0.45 11.84 0.99Bk1 40-100 72.00 12.20 15.80 0.14 13.10 0.22 0.12 11.06 1.10Bk2 100-140 63.40 16.10 20.50 0.07 13.60 0.27 0.13 11.96 1.24

Profile P2Ap 0-40 60.00 12.80 27.23 0.87 19.67 0.43 0.42 8.89 2.61Btc 40-80 29.60 19.70 50.70 0.45 39.20 2.21 0.25 17.09 6.712Btk 80-120 33.10 33.10 33.80 0.78 31.50 2.14 0.22 14.61 5.90

Profile P3

% meq/100g

Profile P3Ap 0-20 67.15 16.55 16.30 0.81 13.40 0.29 0.53 5.33 1.42Bt 20-70 67.60 16.00 16.40 0.47 12.70 0.30 0.31 4.55 1.10

Btcg 70-100

Profile P4Ap 0-50 68.27 13.87 17.87 0.66 17.97 0.28 0.25 12.62 1.41Bk 50-120 70.35 13.85 15.80 0.23 16.70 0.41 0.10 13.77 2.12

2Bw 120-160

Profile P5Ap 0-40 36.97 42.70 20.33 1.32 29.03 0.34 1.25 22.02 4.56Bw 40-80 36.90 27.50 35.60 0.78 28.10 0.66 1.15 18.63 7.67

2Bk1 80-120 35.80 26.50 37.70 0.50 26.50 1.17 0.71 17.22 7.41

prove preliminari di infiltrazione e successivo esaurimento perla determinazione delle proprietà idrauliche (funzioni diritenzione idrica e di conducibilità idraulica);

esperimenti di moto miscibile con tracciante per ladeterminazione delle caratteristiche del trasporto dei soluti(funzione di distribuzione dei tempi di trasferimento);

FASI DELLA SPERIMENTAZIONE

cicli di infiltrazione ed esaurimento con acque reflue;

prove di infiltrazione ed esaurimento come al punto (1) e dimoto miscibile come al punto (2) per la quantificazione deglieffetti del trattamento con acque reflue sulle funzioni diritenzione idrica e di conducibilità idraulica, sullecaratteristiche dispersive e sulla distribuzione dei tempi ditrasferimento dei soluti nel suolo.

pH 7.73 Ferro totale µg/l 72.10Conducibilita' a 25 ºC mS/cm 1146.70 Ferro disciolto " 59.20Potenziale redox mV 182.10 Manganese totale " 22.70Azoto ammoniacale mg/l 25.77 Manganese disciolto " 19.65Azoto nitroso mg/l N 0.13 Alluminio totale " 110.10Azoto nitrico " 0.37 Alluminio disciolto " 94.75Azoto totale " 29.20 Cromo totale " <1Fosforo totale mg/l P 1.64 Cromo disciolto " <1Fosforo reattivo " 1.33 Zinco totale " 26.63Cloruri mg/l 133.83 Zinco disciolto " 20.47

Composizione media delle acque reflue utilizzate nella sperimentazione

Cloruri mg/l 133.83 Zinco disciolto " 20.47Solfati " 121.30 Cadmio totale " <1Alcalinita' meq/l 4.81 Cadmio disciolto " <1COD mg/l O2 34.35 Piombo totale " <5Sodio mg/l 103.86 Piombo disciolto " <5Potassio " 18.24 Nichel totale " <5Calcio " 52.76 Nichel disciolto " <5Magnesio " 19.74 Rame totale " <5SAR meq/l 1/2 3.06 Rame disciolto " <5TC mg/l 53.93 Arsenico totale " <10TOC " 13.27 Arsenico disciolto " <10IC " 45.44 Boro totale " 831.70AOX µg/l 102.30 Boro disciolto " 811.45

θ (−)θ (−)θ (−)θ (−)7 cm

Profilo P1

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5t (h)

0.00 0.50 1.00 1.50 2.00 2.50αααα (cm)

initial columnfinal column

0 0.1 0.2 0.3 0.4 0.5C/C0

3.0 h 20.0 h

z (cm)

5.0 h nW W

0.0 10.0 20.0 30.0

0.0 20.0 40.0 60.0

10.0 30.0 50.00

0.00 0.50 1.00 1.50(mg/kg)

Rame nW

Rame W

Zinco nW

Zinco W

Cromo nW

Cromo W

Boro nW

Boro W

0.0 0.5 1.0 1.5

Boro nWBoro WBoro nW simBoro W sim

I (cm)

Profilo P5

0.0 2.0 4.0 6.0t (h)

I initial characterization

I final chracterization

Prove di trasporto con cadmio

Colonna P2 Curva di efflusso per i coliformi fecali

measured

dual-permeability simulated

0 5 10 15 20 25 30t (h)

Coppola A., Santini A., Botti P., Vacca S., Comegna V., Severino G., 2004.. Methodological approachto evaluating the response of soil hydrological behavior toirrigation with treated municipalwastewater. Journal of Hydrology 292 (2004) 114–134.

Il comportamento idrologico dei suoli nella valutazione

delle acque saline per l’irrigazione

Threshold values of SAR of topsoil and EC of infiltrating water for maintenance of soil permeability (after Rhoades 1982)

Salt tolerance of grain crops (after Maas and Hoffman 1977)

J.D. Rhoades, A. Kandiah, and A.M. Mashali. The use of saline waters for crop production - FAO irrigation and drainage paper 48

Ayers and Westcot

Mass and Hoffman (1977) definiscono una soglia di salinità (ECmax) e

Hanks, 1983

Mass and Hoffman (1977) definiscono una soglia di salinità (ECmax) e una pendenza (ECslope) come caratteristiche specifiche di ciascuna coltura ma non danno ragioni biofisiche dell’esistenza di queste caratteristiche

Na2SO4 or NaCl

(Palmer, 1937; Magistad, 1943; United States Salinity Laboratory (1954); Bernstein, 1962; Maas, 1990; Grieve et al., 2001

Salinity-Fertility interactions

Lunin et al., 1963; Ravikovitch and Porath, 1967; Bernstein, 1974; Peters, 1983;

Interazioni Yield-Salinity-Edaphic

Field or Greenhouseand Soil Water Content (and depth distribution of EC)

Yaron, 1972; Stepphun et al., 2005;….

Growth stage

Lunin et al., 1963; Francois et al., 1994; Katerji et al., 1998

Spatial variation in crops is the result of a complex interaction of salinity with:biological (e.g., pests, earthworms, microbes),

edaphic (e.g., organic matter, nutrients, texture),

anthropogenic (e.g., leaching efficiency, soil compaction due to

D.L. Corwin and S.M. Lesch, 2005. Apparent soil electrical conductivity

measurements in agriculture. Computers and Electronics in Agriculture 46 (2005) 11–43

anthropogenic (e.g., leaching efficiency, soil compaction due to farm equipment),

topographic (e.g., slope, elevation), and

climatic (e.g., relative humidity, temperature, rainfall) factors.

Variability of Soil Hydrological Variability of Soil Hydrological BehaviourBehaviour

Salt tolerance classification of crops according to soil salinity and to water stress day index

N. Katerji, J.W. van Hoorn A. Hamdy, M. Mastrorilli

Agricultural Water Management 43 (2000) 99-109

60 seeds per lysimeter and harvested on 4 July 2011

0.15m 1.3m

TDR probes

Soil profile (B)

Expanded clay

Drainage reservoir

Evaluation of the time-domain reflectometry (TDR)-measured composite dielectric constant of root-mixed soils for estimating soil-water content and root density

M.A. Mojid*, H. Cho

Journal of Hydrology 295 (2004) 263–275

Photo 5: TDR measurements in root-mixed soils

Irrigazione z=0-40 cm alla “CC”

Irrigazione con livelli di salinità corrispondenti al 90%, 70% e 50%

Lysimeter A (90%)Lysimeter A (90%)Lysimeter A (90%)Lysimeter A (90%) Lysimeter B (75%)Lysimeter B (75%)Lysimeter B (75%)Lysimeter B (75%)

Lysimeter C (50%)Lysimeter C (50%)Lysimeter C (50%)Lysimeter C (50%)

60 seeds per lysimeter and harvested on 4 July 2011

Lysimeter A Before drying (60°C) After drying Fruit 471.49 359.06 Leaves and stems 501.46 106.26 Total 972.95 465.32 Stems length 27.3

Lysimeter B Before drying (60°C) After drying Fruit 648.63 368.39 Leaves and stems 550.94 116.46 Total 1199.57 484.85 Stems length 27.93

Lysimeter C Before drying (60°C) After drying Fruit 833.84 427.88 Leaves and stems 596.22 118.00 Total 1430.06 545.88 Stems length 35.4 Reference Lysimeter Before drying (60°C) After drying Fruit 864.54 458.82 Leaves and stems 604.47 130.00 Total 1500.10 594.34 Stems length 37.3

-0.800

-0.300

07/05/2011 17/05/2011 27/05/2011 06/06/2011 16/06/2011 26/06/2011 06/07/2011

-2.800

-2.300

-1.800

-1.300

lysimeter A

lysimeter B

lysimeter C

5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011

z=10 cmz=25 cmz=40 cmz=55 cmz=70 cmz=85 cm

Lysimeter A - 100%

0.150Lysimeter B - 75%

5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011

5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011t (days)

Vr (-)Lysimeter C - 50%

y = 0.136x - 5515.3

4/27/2011 5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011 7/16/2011

z=10 cm

z=25 cm

z=40 cm

z=55 cm

z=75 cm

transpiration blockedLysimeter A - 100%

y = 0.174x - 7054.710

15transpiration blockedLysimeter B - 75%

y = 0.174x - 7054.7

4/27/2011 5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011 7/16/2011

y = 0.245x - 9932.5

4/27/2011 5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011 7/16/2011t (days)

yield=0%

yield=50%

Lysimeter C - 50%

)lysimeter A

lysimeter B

lysimeter C

0 50 100 150depth z (cm)

Yaron, 1972

15Lysimeter B - 75%

0 20 40 60 80 100 120

Lysimeter A - 100%90%

0 20 40 60 80 100 120

0 20 40 60 80 100 120 z (cm)

-1) Lysimeter A - 50%

Hanks, 1983

hh00 modifica l’attingimento modifica l’attingimento radicale ma anche la radicale ma anche la distribuzione delle radicidistribuzione delle radici

Simulated ECsw

z=10 cmz=25 cmz=75 cm

Lysimeter A - 90%

27/04/2011 07/05/2011 17/05/2011 27/05/2011 06/06/2011 16/06/2011 26/06/2011

z=75 cm

t (days)

steady-state LF 8% > LF from monitoring and modeling

Scala di campo

Cr(t=14h)

horizontal distance (m)

3 6 9 12 15 18 21 24 27 30 33 360.08

Cr(t=14h)

3 6 9 12 15 18 21 24 27 30 33 360.08

Yield, LAI, height, ET….

3 6 9 12 15 18 21 24 27 30 33 36

HORIZONTAL DISTANCE (m)

θ (-)

3 6 9 12 15 18 21 24 27 30 33 36

(%)SKELETON

3 6 9 12 15 18 21 24 27 30 33 36

α−clay

z=40 cm

0 4 8 12 16 20 24

α−clay

z=25 cm

0 4 8 12 16 20 24

α−clay

z=7.5 cm

0 4 8 12 16 20 24

α−skeleton

z=40 cm

1.00α−skeleton

z=25 cm

1.00α−skeleton

z=7.5 cm

0 4 8 12 16 20 24

spatial scale (m)

0 4 8 12 16 20 24

Coppola A., Comegna A. Dragonetti G., Dyck M., Basile A., Lamaddalena N., Kassab M. and ComegnaV., 2011. Solute transport scales in an unsaturated stony soil. Advances in Water Resources. Volume34, Issue 6, June 2011, Pages 747-759.doi:10.1016/j.advwatres.2011.03.006

Cr(t=14h)

3 6 9 12 15 18 21 24 27 30 33 360.08

secondary drainage net

A A’

Piezometri

φ ≈ 0.06 m

Profondità 1.5 m

0-15cm

10 SITES

FOUR TDR PROBES AT FOUR DEPTHS FOR EACH SITE

secondary drainage net

A A’

Piezometri

φ ≈ 0.06 m

Profondità 1.5 m

Steady state modeling

LF=0.19

Transient modeling + monitoring

LF=0.08

The EM device mounted on a custom-made cart constructed of nonmetallic materials

EM38DD – GeonicsVDM – 14,6 KHzHDM – 17KHz

Profiler EMP – 400 , GSSIMultifrequenza

0 75 150mS/m

Generazione Campi Randome tecniche di Simulazione Montecarlo

HESSD - Special Issue

Catchment classification and PUBEditor(s): A. Castellarin, P. Claps, P. A. Troch, T. Wagener, and R. Woods

Potential and limitations of using soil Potential and limitations of using soil mapping information to understand landscape hydrology

F. Terribile, A. Coppola, G. Langella, M. Martina, and A. BasileHydrol. Earth Syst. Sci. Discuss., 8, 4927-4977, 2011

CONCLUSIONICONCLUSIONI

Non puo`infatti essere noto a priori il potenziale effetto di acque reflue sulle proprieta` fisiche e sul comportamento idrologico dei

La conoscenza della sola composizione delle acque reflu e saline e` una condizione necessaria ma non sufficiente a stabilirne la idoneita` per l`uso irriguo;

reflue sulle proprieta` fisiche e sul comportamento idrologico dei suoli, effetto che puo` essere anche molto variabile con le caratteristiche dei suoli e con la gestione dell’irrigazione

È sempre auspicabile affiancare al controllo delle acque, anche un monitoraggio caso per caso delle proprieta` e del comportmento dei suoli, nonché della lor variabilità

In generale, tuttavia, un impianto di depurazione di liquami urbani

prevede:

� una sezione di trattamenti preliminari per rimuovere il materiale galleggiante e quello più

grossolano;

� un trattamento primario (o sedimentazione primaria) per la rimozione dei solidi dei solidi

sedimentabili;

� un trattamento secondario o biologico per la biodegradazione delle sostanze organiche;

� un trattamento di disinfezione per la riduzione della carica microbica;

� una parallela linea fanghi per il trattamento e lo smaltimento finale dei fanghi primari e

secondari.

Table 4 CROP TOLERANCE AND YIELD POTENTIAL OF SELECTED CROPS AS INFLUENCED BY IRRIGATION WATER SALINITY (ECw) OR SOIL SALINITY (ECe)1

YIELD POTENTIAL2

Adapted from Maas and Hoffman (1977) and Maas (1984). These data should only serve as a guide to relative tolerances among crops. Absolute tolerances only serve as a guide to relative tolerances among crops. Absolute tolerances vary depending upon climate, soil conditions and cultural practices. In gypsiferous soils, plants will tolerate about 2 dS/m higher soil salinity (ECe) than indicated but the water salinity (ECw) will remain the same as shown in this table.

θ−θθ−θ=

( ) ( )( ) ( )

eer dS

SkSk e

== ∫∫

Modelli parametrici per le funzioni θθθθ(h) e k(θθθθ)

( ) ( )0e

0es ShShk

∫∫

( ) ( ) ( ) n1-1m 112

−−== τm

eer SS

Bruggeman’s 2-phase dielectric mixture model (Hasted, 1973):

M.A. Mojida, H. Chob, 2004. Evaluation of the time-domain reflectometry (TDR)-measured composite dielectric constant of root-mixed soils for estimating soil-water content and root density. Journal of Hydrology 295 (2004) 263–275

4-phase dielectric mixture model (Dobson et al., 1985)4-phase dielectric mixture model (Dobson et al., 1985)

Giese and Tiemann (1975)

ECa – ECw relationshipECa – ECw relationship

ECa – ECe relationship

Until more information is available on how crops respond to time and space varying osmotic and matric stresses as a function of irrigation management, soil water retentivity characteristics and atmospheric stresses, and practical dynamic models are developed to predict these stresses, the following parameters are recommended for evaluating the salinity and toxicity hazards of irrigation waters. recommended for evaluating the salinity and toxicity hazards of irrigation waters.

In some coastal plains, groundwater abstraction results in saltwater intrusion and a deterioration in groundwater quality. The Volturno and Sele Plains in southern Italy are areas where this problem has been observed.

Historically, five methods have been developed for determining soil salinity at field scales:

(i) visual crop observations,

(ii) the electrical conductance of soil solution extracts or extracts at higher than normal water contents,

(iii) in situ measurement of electrical resistivity (ER),

(iv) non-invasive measurement of electrical conductance with electromagnetic induction (EM), and most recently

(v) in situ measurement of electrical conductance with time domain reflectometry (TDR).

0 . 0 0 0

0 . 0 2 0

0 . 0 4 0

0 . 0 6 0

0 . 0 5 0 . 0 1 0 0 . 0 1 5 0 . 0 2 0 0 . 0

0 . 0 4 0

0 . 0 6 0

( )1, ztE

0 3 6 9 12λ

( )1, ztVAR

( )2, ztECD

0 . 0 0 0

0 . 0 2 0

0 . 0 4 0

0 . 0 6 0

0 . 0 5 0 . 0 1 0 0 . 0 1 5 0 . 0 2 0 0 . 0

0 . 0 0 0

0 . 0 2 0

0 . 0 4 0

0 . 0 5 0 . 0 1 0 0 . 0 1 5 0 . 0 2 0 0 . 0

( )2, ztE

( )2, ztVAR

( )nztE ,

( )nztVAR ,

Ayers and Westcot (1985) definiscono la salinità come una condizione in cui i sali in soluzione nella zona radicale si accumulano in concentrazioni tali da indurre una riduzione della resa colturale. In particolare, i soluti in soluzione acquosa riducono il potenziale osmotico potendo quindi ridurre gli attingimenti radicali (Wadleigh and Ayers, 1945; Munns and Termaat, 1986; Jacoby, 1999; Katerji et al., 1997)

0.0000.1250.2500.3750.500

4/27/2011 5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011 7/16/2011

01530456075z=10 cm

z=25 cmz=40 cmz=55 cmz=70 cmz=85 cmz=100 cmirrigation height

Lysimeter A - 100%

0.5006075Lysimeter B - 75%

4/27/2011 5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011 7/16/2011

015304560

4/27/2011 5/7/2011 5/17/2011 5/27/2011 6/6/2011 6/16/2011 6/26/2011 7/6/2011 7/16/2011

t (days)

θTDR (-)

01530456075

irriga

Lysimeter C - 50%

0 5 10 15 20 25 30 35 40

Distance (m)

Intial timemiddle timeFinal timeMean values of water content

)Intial timemiddle timeFinal time

Contenuti d’acqua misurati

0 5 10 15 20 25 30 35 40

Distance (m)

middle timeFinal timeMean values of water content

0 5 10 15 20 25 30 35 40

Distance (m)

Intial timemiddle timeFinal timeMean values of water content

Criteria and Standards for Assessing Suitability of Saline Water for Irrigation

The suitability of a water for irrigation should be evaluated on the basis of criteria indicative of its potential to create soil conditions hazardous to crop growth (or to animals or humans consuming those crops). Relevant criteria for judging irrigation water quality in terms of potential hazards to crop growth are primarily:

· Permeability and tilth The interactive, harmful effects of excessive exchangeable sodium and high pH in the soil and low electrolyte concentration in the infiltrating water on soil structure, permeability and tilth. These effects are evidenced by disaggregation, crusting, poor tilth (coarse, cloddy and compacted topsoil aggregates) and by a reduced rate of water infiltration.· Salinity The general effect of salts on crop transpiration and growth which are thought to be largely osmotic in nature and, hence, related to total salt concentration rather than to the individual concentrations of specific salt constituents. These effects are generally evidenced by reduced transpiration and proportionally retarded growth, producing smaller plants with fewer and smaller leaves.

J.D. Rhoades, A. Kandiah, and A.M. Mashali. The use of saline waters for crop production -FAO irrigation and drainage paper 48

· Toxicity and nutritional imbalance The effects of specific solutes, or their proportions, on plant growth, especially those of chloride, sodium and boron. These effects are generally evidenced by leaf burn and defoliation.

The suitability of the water for irrigation is evaluated in terms of the permeability and crusting hazards using ECiw and estimates of the ESP (or SAR) that will result in the topsoil and permissible limits of ESP (SARsw, SARiw or adjusted SARiw), ECiw and pH for the conditions of use. Soil permeability problems are deemed likely if the ESP - ECiw combination lies to the left of a threshold relation between SARsw (ordinate) and ECiw (abscissa) of the type shown in Figure 2. Since the SARsw - ECiw threshold relations of many soils may differ from that given in Figure 2 (Suarez 1990), specific relations should be used for the specific soils of interest; Figure 2 should only be used if specific relations are not available. Note that the permeability hazard threshold relation curves downward at low SARsw values (about 10) and intersects the ECiw axis at some positive value (about 0.3) because of the dominating effect of electrolyte concentration on soil aggregate stability, dispersion and crusting at low salinities.

CC00CCii

( ) ( )ztCVz

),( ztE

),( ztVAR0.000

0.0 100.0 200.0 300.0t

3 6 9 12 15 18 21 24 27 30 33 36

α (cm)

3 6 9 12 15 18 21 24 27 30 33 36

VAR1,1

VAR3,1

VARn,1

Dalla scala locale alla scala di campo

Lag=K=1

VAR2,1

( )( )KiK

VAREVAR

VAR2,2

Dalla scala locale alla scala di campo

Lag=K=2

( )( )KiK

VAREVAR

VAR1,2

VARn,2

z=7.5 cm

0 10 20 30 40

z=25 cm

0 10 20 30 40

z=40 cm

0 10 20 30 40

spatial scale (m)

Table 2 LABORATORY DETERMINATIONS NEEDED TO EVALUATE COMMON IRRIGATION WATER QUALITY PROBLEMS: Source: Ayers and Westcot, FAO IRRIGATION AND DRAINAGE PAPER 29

Water parameter Symbol Unit 1 Usual range in irrigation water

SALINITY

Salt Content

Electrical Conductivity ECw dS/m 0 – 3 dS/m

Total Dissolved Solids TDS mg/l 0 – 2000 mg/l

Cations and Anions

Calcium Ca++ me/l 0 – 20 me/l

Magnesium Mg++ me/l 0 – 5 me/l

Sodium Na+ me/l 0 – 40 me/l

Carbonate CO-- me/l 0 – .1 me/lCarbonate CO--3 me/l 0 – .1 me/l

Bicarbonate HCO3- me/l 0 – 10 me/l

Chloride Cl- me/l 0 – 30 me/l

Sulphate SO4-- me/l 0 – 20 me/l

NUTRIENTS2

Nitrate-Nitrogen NO3-N mg/l 0 – 10 mg/l

Ammonium-Nitrogen NH4-N mg/l 0 – 5 mg/l

Phosphate-Phosphorus PO4-P mg/l 0 – 2 mg/l

Potassium K+ mg/l 0 – 2 mg/l

MISCELLANEOUS

Boron B mg/l 0 – 2 mg/l

Acid/Basicity pH 1–14 6.0 – 8.5

Sodium Adsorption Ratio3 SAR (me/l)1, 2 0 – 15

Over the past decade research has been directed at developing reliable and efficient conversion techniques from ECa back to ECe (Wollenhaupt et al., 1986; McKenzie et al., 1989; Rhoades et al., 1989, 1990, 1991, 1999b; Rhoades and Corwin, 1990; Slavich and Petterson, 1990; Lesch et al., 1992, 1995a, 1995b, 1998; LopezBruna and Herrero, 1996; Rhoades, 1996; Mankin and Karthikeyan, 2002). and Herrero, 1996; Rhoades, 1996; Mankin and Karthikeyan, 2002). In the case of converting ECa measured with EM back to ECe, most investigators have used non-linear transformations of EM ECa readings to decrease the errors of the estimates (LopezBruna and Herrero, 1996). However, LopezBruna and Herrero (1996) showed that linear methods of calibration are sufficiently accurate for soil salinity surveys.

HYDRODYNAMIC DISPERSION

D=D0 +λv0n

IL COMPORTAMENTO IDROLOGICO DEI SUOLISUOLI NELLA … · Tech. Rep. Soil and Contaminant Hydrology...

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