D-38300 Wolfenbuettel/Germany P.O.Box 1934; schleiff@salinity.de International Expert for

● Irrigation & Salinity ● Fertilizers & Crops ● Soils & Environment

http://www.salinity.de

SALINITY- SCHLEIFF

COST ACTION FA0901 – Halophytes/Kecskemet Conf. 4-6.09.2013

CROP SALT TOLERANCE

UNDER BRACKISH WATER IRRIGATION

AS AFFECTED BY ROOT MORPHOLOGY

Dr. Uwe Schleiff

CROP SALT TOLERANCE UNDER BRACKISH WATER

IRRIGATION AS AFFECTED BY ROOT MORPHOLOGY

CONTENTS

1. Introduction: Some Practice Related Aspects

2. Definitions for the Term ‘Salt Tolerance’

3. Flows of Water and Salts in Soils under Brackish Irrigation

4. Model Calculation on the Impact of Root Morphology

5. Set-Up of a Soil-Based Vegetation Technique

6. Some Experimental Results

7. Summary and Conclusions

List on Demand for SOIL GROWN Salt Tolerance of Plants/Crops

Development of Salt-Affected Land for Crops/Plants

Application of Marginal Waters for Landscape Irrigation and Gardening

Re-Use of Brackish Drainage Waters Resources for Crop Irrigation

Developing Techniques for Precision Brackish Water Irrigation

Concepts for Breeding of Salt Tolerant Crops

Tropical Coastal Marine Systems: Protection of Mangrove Forests and

Other Halophytes

Development of Brackish Waste Waters as Resource for Crop Irrigation

Avoidance of Environmental Desasters by Lagoon Storage of Sewage

Waters

Development of Brackish Groundwater Resources for Crop Irrigation

Reduction of Water Requirement for Leaching under Controlled Irrigation

CHINA: Google Earth Foto from a Salt-Affected Project Site/Kashgar Prefecture

OMAN: Dying Palm Trees Caused by Coastal Seawater Intrusion

QATAR: Uncontrolled Doha Sewage Water Disposal

PERU: Brackish Wastewater Pumping from a Drainage Canal for Vegetable Irrigation

Table 2: Wastewater irrigation statistics for selected countries

(Hamilton et al., 2007; Kloss, 2001)

COUNTRY/ Region

Land Area Irrigated with Wastewater: ha

Volume of Wastewater used for Irrigation: million m³/year

Worldwide 20.000.000 - Australia - 156 California - 548-730 China >1.330.000 - Egypt 42.000 - Florida - 803 Germany ~30.000 - Iran - 70 Israel - 400 Italy >4.000 - Jordan - 74 Kuweit 4.470 - Mexiko >350.000 - Morocco 8.000 - Pakistan 32.500 - Peru >5.000 - S. Africa 22.000 - Spain 9.500 - Tunisia - 8,7

Definitions of ‚SALT TOLERANCE’

Irrigated Agriculture (Crop Salt Tolerance)

Biology/Plant Physiology

Focus on:

Soil-Based Appraisal

Focus on:

Hydroponic-Based Appraisal

Y = 100 – b (ECe – a)

Y = rel. Yield/Crop Growth in %

a = ECe (dS/m), where Yield Loss Starts

b = Yield Loss in %, expected by an ECe-Increase of 1 dS/m

ECe = Soil Salinity Degree

SaltRESISTENCE

= SaltTOLERANCE

+ SaltREGULATION

TOLERANCE: Ion Pumps, Com-patible Solutes, Photosynthesis, Protoplasmatic Components (Ion Relations, Membrans) etc.

REGULATION: Salt Exclusion, Filtration, Selectivity (root), Desali-nation (Hairs, Glands), Leaf Dropping, Succulence, Compartimentalization etc

Flow of Water and Salts in the Rooted Soil Layer underControlled Brackish Water Irrigation

Impact of Soil-Root Interaction on Crop Salt Tolerance

Calculated Impact of Water Depletion by Roots Differing in their Morphologyon Increase of Rhizospheric Soil Water Salinity (resp. Rhizosoil Volumes)

0

5

10

15

20

25

30

35

40

45

0 5 10 15 20

rhizosoil water depleted by roots in ml/10 m root length, RL

EC

sw (

dS

/m)

of

rhiz

oso

il w

ater

ONION MAIZE TOMATO LOLIUM RAPE

Rhizosoil Vol.

CROP cm³/10m RL

Onion 4

Maize 22

Tomato 40

Lolium 52

Rape 62

at FC 40 Vol.%

Pot Volumes as Related to Soil Fractions

Relative Distance to Root Surface per Pot Volume

Soil

Wat

er S

alin

ity:

EC

sw d

S/m

+ BULK SOIL

RHIZOSOIL

+ TRANSITION

ZONE

-------------------------------1000 ml soil volume------------------------

-------------------500 ml soil volume-------------

---------250 ml soil volume------

Root Surface

Look on Rape Seedlings Pre-Grown at Increasing Soil Volumesfor Different Rooting Densities

250 ml Soil Vol.

500 ml Soil Vol.

1000 ml

Soil Vol.

Look on Experimental Set-Up with Rape Seedlings Ready forSaline Treatments

▲

Non Saline

▲

Low

Saline

▲

ModeratelySaline

▲

HighlySaline

Tab. 3: Experimental set-up proposed for quantitative comparison of crop salt tolerance rating

using seedlings (SV = Soil Volume in ml; RD – Rooting Density in length cm/ml soil; ECi of water applied at start of experimental phase)

Salt-Sensitive Crop/Variety Salt-Tolerant Crop/Variety

Salinity Treatment SV-250

RD 1) SV-500

RD 2) SV-1000

RD 3) SV-250

RD 1) SV-500

RD 2) SV-1000

RD 3) Non to Low (ECi 3 dS/m)

very high high moderate very high high moderate

Low to Moder. (ECi 8 dS/m)

very high high moderate very high high moderate

Moder. to High (ECi 15 dS/m)

very high high moderate very high high moderate

1) rhizospheric soil vol. only; 2) rhizo-soil + transition zone 3) rhizo-soil + transit.+ bulk soil vol.

Data on Water Relations Determined fromMeasurement of Pot Water Losses

• Soil Water Content in Vol.% and Soil MatricWater Potential Ψm

• ECsw of Soil Water and Soil Osmotic Water

Potential Ψo

• Total Soil Water Potential Ψt (= Ψm + Ψo)

• Transpiration Rate and Relative Growth Rate (RGR) of shoot-DM

Transpiration and Growth of MODERATELY SALT-TOLERANT Rape Seedlings as Affected by Increasing Soil Water Salinity and Decreasing Soil Water Contents

0

1

2

3

4

5

6

7

0 10 20 30 40 50

ECsw of Soil Water, dS/m

Tra

nsp

irat

ion

Rat

e in

ml

h-1 g

-1 D

M S

hoot

0

5

10

15

20

25

30

35

40RAPE: Salt Tolerance Class MT

11 dS/m treatment;

42 h total transpiration time

A: Soil Water Vol.%

B: Transpiration Rate

FC

50% FC

PWP

So

il Water C

on

tent, V

ol.%

[~RGR ]▼

[2%/h ]

[1%/h ]

[0,5%/h ]

0

1

2

3

4

5

6

7

0 10 20 30 40 50

ECsw of Soil Water, dS/m

Tra

nspi

rati

on R

ate

in m

l h

-1 g

-1 D

M S

hoot

0

5

10

15

20

25

30

35

40

LEEK: Salt Tolerance Class S11 dS/m treatment

42 h total transpiration time

A: Soil Water Vol.%:

B: Transpiration:

Soil W

ater Con

tent, Vol.%

FC

50% FC

PWP

[~RGR ]

▼

[1%/h ]

[0,5%/h ]

0

1

2

3

4

5

6

7

0 10 20 30 40 50

ECsw of Soil Water, dS/m

Tra

nspi

rati

on R

ate

in m

l h

-1 g

-1 D

M S

hoot

0

5

10

15

20

25

30

35

40RAPE: Salt Tolerance Class MT

11 dS/m treatment;

42 h total transpiration time

A: Soil Water Vol.%

B: Transpiration

FC

50% FC

PW

Soil W

ater Content, V

ol.%

[~RGR ]▼

[2%/h ]

[1%/h ]

[0,5%/h ]

Fig. X: Plant Transpiration and Growth, Soil Moisture and Soil Salinity Pattern Presented for a Salt Sensitive and a Salt Tolerant Crop

Schematic Presentation of Lateral Salt Distribution around Roots of Salt-Sensitive and Salt-Tolerant Crops

distance from root surface

sali

nit

y o

f so

il s

olu

tion

Bulk Soil

Rhizospheric Soil (RS)

RS

SALT-SENSITIVE CROP(inefficient root water uptake)

SALT-TOLERANT CROP(efficient root water uptake)

Transition

Zone

root surface

THANK YOU

FOR LISTENING !