crop salt tolerance under brackish … · re-use of brackish drainage waters ... development of...
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D-38300 Wolfenbuettel/Germany P.O.Box 1934; [email protected] 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
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
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