prof. john annandale (university of pretoria) prof. rui brito (university eduardo mondlane) dr....
TRANSCRIPT
Prof. John AnnandaleProf. John Annandale (University of Pretoria) (University of Pretoria)
Prof. Rui BritoProf. Rui Brito (University Eduardo Mondlane) (University Eduardo Mondlane)
Dr. Martin SteynDr. Martin Steyn (University of Pretoria) (University of Pretoria)
Prof. Richard Stirzaker Prof. Richard Stirzaker (CISRO)(CISRO)
byby
Paiva MunguambePaiva Munguambe
WATER & NITROGEN WATER & NITROGEN MANAGEMENT ON SALT-MANAGEMENT ON SALT-
AFFECTED SOILS IN THE CHÓKWÈ AFFECTED SOILS IN THE CHÓKWÈ IRRIGATION SCHEME, IRRIGATION SCHEME,
MOZAMBIQUEMOZAMBIQUE----------------- - Progress ReportProgress Report - -----------------
Final Scientific Workshop – CP 17Final Scientific Workshop – CP 17JHB, 15 to 18 June 2009JHB, 15 to 18 June 2009
UEM/FAEF
IntroductionIntroduction
IntroductionIntroduction……
Some features of the CIS Designed in the 50s… drainage was not so relevant….!! Water from Massingir & Macarretane Dams (Gravity) HICEP…… 30,000 ha ( 1,000 ha salinazed & only 6 to 7,000 ha
effectively cultivated) 12,000 farmers (Small <4 ha; Medium 4 to 15 ha; big > 20
ha) Private company (MIA) Water Users Association Rice (summer crop) : 2 to 4.5 ton/ha Vegetables + maize (winter crops): tomatoes up to 60
ton/ha; Heavy clay soils (low infiltration & transmissivity rates) Good irrigation water ( 0.5 dS/m) Poor crop and irrigation water management (Irrigation
Efficiency < 30%) Poor infrastructure management (State & farmer's
management)
IntroductionIntroduction……
Research questions, hypotheses & objectives
(i) How to leach salts but conserve nitrogen on salt-affected soils of the CIS?
Hypothesis 1: Improved irrigation water and nitrogen management
strategies will increase water and nitrogen use efficiency
in salt-affected soils.
Hypothesis 2: Shallow water-table in salt-affected soils affects the salt
dynamics in the root zone.
Hypothesis 3: Current irrigation water management under heavy clay
textured soils with a shallow water table contributes
both to nitrogen losses and low water use
efficiency.
MethodologyMethodology
• 3 Saline Sites (Non-S, Mod-S & Saline)
• Trial Layout (2X2 Factorial; 3 Rep; CRBD):2007; 08;
09
• Wtreatments- Calendar & SWD to FC
• Ntreatments – 100 kg/ha ( 5 on/ha) & 200 kg/ha (>10 ton/ha)
• WFD – drained water (N & Salt Analysis) at depths
• Monitoring (eg., climate & parameters, yields, etc.)
• ? Modelling exercise!!?
Methodology…
Instrumentation & Monitoring
Preliminary ResultsPreliminary ResultsEC & N03 drained water (WFD): 3 Sites Dry SeasonEC & N03 drained water (WFD): 3 Sites Dry Season
Preliminary ResultsPreliminary Results……
EC & N03 drained water (WFD): 3 Sites Dry SeasonEC & N03 drained water (WFD): 3 Sites Dry Season
Preliminary ResultsPreliminary Results……
EC & N03 drained water (WFD): 3 Sites Wet SeasonEC & N03 drained water (WFD): 3 Sites Wet Season
Preliminary ResultsPreliminary Results……
EC & N03 drained water (WFD): 3 Sites Wet SeasonEC & N03 drained water (WFD): 3 Sites Wet Season
Preliminary resultsPreliminary results……
Yield (Maize PAN 67): Dry & Wet SeasonsYield (Maize PAN 67): Dry & Wet Seasons
Preliminary ResultsPreliminary Results……
Salt accumulation process: ModSaline & Saline Salt accumulation process: ModSaline & Saline SitesSites
Preliminary ResultsPreliminary Results……
Salt accumulation process – Saline & ModSaline Salt accumulation process – Saline & ModSaline sitessites
Rep
1
Rep
2
Rep
3
WT (WT (1.2 m to 0.90 m)1.2 m to 0.90 m)
Irrigation canal waterlogging
20 m20 m
Challenges & On-going Challenges & On-going ActivitiesActivities• REGIONAL & in situ HYDROLOGY AFFECTS SALT
DYNAMICS
– WHAT MODELLING APPROACH CAN BETTER SUIT?
• Modelling processes…. understanding the causes & effects (Micro
scale) …
• Modelling better future management scenarios (Macro scale) …
Water vs. N & Salts
• ARE THERE APPROPRIATE MODELS?
– Water, Salts & Nitrogen Management (Saltmed; APSIM; etc.)
Challenges & On-going Challenges & On-going ActivitiesActivities……
INPUTSINPUTSField Trials ResultsoSoil data
Texture; Soil Layers; Saturated Hydraulic Conductivity; Infiltration Rates;
oClimate dataETo & Rainfall
oIrrigation & drainage dataDepths; Timing & EC; Irrigation Water Management
oGroundwater dataDepth & EC
oCrop dataPlanting date; Yield, etc.
HYROLOGICAL MODEL
CROP MODEL
WATER & NUTRIENTS MODEL
INTEGRATED MODELLING
SOUND
ENVIRONMENTAL
SCENARIOS
FARMER’S
PERSPECTIVES
OUTPUTS
Recommendations
Improved Irrigation Water and Nitrogen & Salt Management
Practices
Challenges & On-going Challenges & On-going ActivitiesActivities……
• AGREED ON THE CHAPTERS (THESIS)
• WRITING UP
• HOPEFULLY TO SUBMIT BY THE END DECEMBER 2009
Thank you!