This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Mladen Todorovic & Rossella Albrizio
(CIHEAM-IAMB, Italy)
Ljubomir Zivotic
(Institute for Water Management “Jaroslav
Cerni”, Belgrade, Serbia)
Deficit Irrigation of Sunflowerunder Mediterranean environmental
to reduce the consumptive use of water by crops in
the Mediterranean agriculture and thereby to release
water resources for other uses
Objectives of the experiment:
to analyse sunflower growth under five water regimes
to determine critical stages of crop growth to water
deficit
to quantify the impact of water stress duration and
intensity
Sunflower characteristics
-Helianthus annuus L. hybrid Sanbro_MR
-Origin Spain
-Early flowering
-Early maturity
-Very good and good mid-late and late early vigour
-Drought and heat tolerant
-High yield potential
-Medium oil content
-Objective density 60000 per hectare
(Valenzano - BA, Southern Italy; 4103’N, 1652’E, 72 m a.s.l.)
Clay loam soil, of 70 cm depth and two layers, avg. SWC 150 mm/m
Agronomic parameters
Sowing on April 10th
Plant density 5.56 plants / m2
Harvesting on August 8th
Water regimes:
Full irrigation
Rainfed conditions
Full irrigation until the flowering and then 70% of CWR
70% of CWR during the whole season
70% of CRW until the flowering and then rainfed conditions
Measured parameters
Plant measurements (11 times during season, each 7-15 days):
-Leaf number, plant height, leaf area index, dry biomass of each plant organ (roots, stems, leaves, heads, seeds)
-FINT values obtained 6 times during a growing season (LI-COR, Light bar)
Soil characteristics:
-Depth, texture, nutrients
Climatic data:
-maximum and minimum air temperature, maximum and minimum relative humidity, solar radiation, wind speed, precipitation
Management data:
-Irrigation water volumes
Estimated parameters
Climatic data:
-reference evapotranspiration FAO P_M equation
Soil parameters:
-Water holding capacity (saturation, field capacity, wilting point), infiltration rate
Plant characteristics:
-each phenological stage (emergence, head visible, flowering, maturity) was considered to occur when it was observed in 80% of plants
-crop coefficient Kc
Management:-soil water balance and irrigation water requirements were calculated on the basis of FAO 56 Irrigation and Drainage paper
Weather data
ETo
Soildata
Crop data
ETc; Rz_SWB; IRR_net; Y/Ymax
IRR_gross
Managementdata
FAO P_MHargreaves
FAO P_M_Rs_mod
variable number of growth stages
variable application efficiency
Optional ETo method
ETomodule
Soil waterbalancemodule
Irrigationmodule
Source: Todorovic, 2006
Root zone soil water depletion for full irrigation treatment
Days after sowing
De
ple
tio
n (
mm
)
0
10
20
30
40
50
60
70
80
90
100
110
0 10 20 30 40 50 60 70 80 90 100 110 120
TAW [mm]
RAW [mm]
Depletion [mm]
8th April 8th August
F M
Days after sowing
De
ple
tio
n (
mm
)
0
10
20
30
40
50
60
70
80
90
100
110
0 10 20 30 40 50 60 70 80 90 100 110 120
TAW [mm]
RAW [mm]
Depletion [mm]
Root zone water depletion for treatment with full irrigation until flowering and then 70% of full irrigation requirements
(slight water stress)
F
M
Days after sowing
De
ple
tio
n (
mm
)
0
10
20
30
40
50
60
70
80
90
100
110
0 10 20 30 40 50 60 70 80 90 100 110 120
TAW [mm]
RAW [mm]
Depletion [mm]
Root zone water depletion for 70% of full irrigation requirements during the whole season
(moderate water stress)
F M
0
10
20
30
40
50
60
70
80
90
100
110
0 10 20 30 40 50 60 70 80 90 100 110 120
TAW [mm]
RAW [mm]
Depletion [mm]
Days after sowing
De
ple
tio
n (
mm
)
Root zone water depletion for 70% of full irrigation requirements until the flowering and then rainfed
(strong water stress)
F
M
0
10
20
30
40
50
60
70
80
90
100
110
0 10 20 30 40 50 60 70 80 90 100 110 120
TAW [mm]
RAW [mm]
Depletion [mm]
Days after sowing
De
ple
tio
n (
mm
)Root zone water depletion for rainfed treatment
F M
Irrigation date DAS Net irrigation supply (mm)
Treatment A
Treatment B
Treatment C
Treatment D
15-Apr-05 7 16.6 16.6 16.6 16.6
28-Apr-05 20 29.1 29.1 20.6 20.6
06-May-05 28 11.6 11.6 8.1 8.1
16-May-05 38 19.3 19.3 9.9 9.9
21-May-05 43 23.3 23.3 18.6 18.6
31-May-05 53 36.6 36.6 25.5 25.5
14-Jun-00 67 55.3 55.3 38.8 38.8
22-Jun-05 75 49.5 34.9 34.9 -
29-Jun-05 82 40.7 29.1 29.1 -
05-Jul-05 88 49.5 34.6 34.6 -
19-Jul-05 102 43.7 30.6 30.6 -
28-Jul-05 111 43.7 30.6 30.6 -
TOTAL (mm) 122 418.9 351.6 298.0 138.2
Irrigation Water management
Total Precipitation during growing season – 110.0 mm (at the beginning of full development, after head apperance/10 days before flowering, between flowering and maturity and one week after maturity)
Deficit irrigation (up to 70% of CWR) is an acceptable strategy for sunflower.
Importance of irrigation between head appearance through flowering up to maturity has been demonstrated.
Possible rainfed production under Southern Italy climatic conditions has been observed (early sowing, depends on rainfall distribution, initial soil water content…)
Strong correlation of irrigated water and obtained biomass and yield was observed. Translocation of assimilates is favored under mild and moderate water stress, while harvest index is strongly reduced under severe water stress.
Both RUE and WUE have shown not conservative behaviour for different water regimes
RUE should be presented as a two stages value (pre- and post-anthesis)
WUE should be presented as a three stage value (initial, pre- and post-anthesis)
Acknowledgements:
•EC 6TH Framework Programme (INCO-MED)
•DIMAS Partners
•IAMB Technical staff: Mr. C. Ranieri, Mr. R. Laricchia, Mr. A. Divella,