HYDRAULIC REDISTRIBUTION AND IT’S POTENTIAL FOR FOOD PRODUCTION

Professor José Miguel Reichert Física do Solo- UFSM Sérgio Ely V. G. A. Costa WATER CYCLE

LimpoporakRAMSAR (2011) BLUE WATER VS GREEN WATER

INVISIBLE WATER

Hamdy (2008) BLUE WATER = SHARE OF WATER RESOURCES STORED IN RIVERS, LAKES AND THAT IS CONTROLLED BY PHYSICAL PROCESSES GREEN WATER= WATER THAT IS INFLUENCED BY BIOLOGICAL PROCESSES SUCH AS EVAPO-TRANSPIRATION BY VEGETATION AND STORED AS MOISTURE WATER USE

POPULATION CLIMATE TIME ECONOMY

INDICATOR ??????

“WITHDRAWALS-TO-AVALABILITY RATIO”

LONG TERM EFFECTS WATER AVAILABILITY

Fonte FEOW disponível em: http://www.feow.org WATER USE WATER USE SECTORS

ANNUAL WITHDRAWALS

Menzel & Matovelle (2010)

IRRIGATION GREEN WATER USE EFFICIENCY

100 90 80 Today 2030 70 60 50 40 30 20 10 0

(FAO, 2010) http://www.feow.org

EFFICIENCY

WITHDRAWALS IMPROVING WATER PRODUCTIVITY WHERE DOES THE RAINWATER GO ? RAIN RAINFALL PARTIONING

RF – (E+T+R+D) D= 10-30% R= 10-25% E= 30-50% T= 15-30% Hillel (2008) ROOT-ZONE WATER BALANCE

CHANGES IN STORAGE= GAINS – LOSSES 4-5 CROP YIELDS !!!! (ΔS + ΔV) = (P+I+U) – (R+D+E+T) GREEN GREEN WATERREQUIREMENT CROPOF % GREEN WATER REQUIREMENT GREEN WATER FLOW PRODUCTIVE WATERGREEN USE SOIL WATER RECHARGE SOIL WATER RAIN INPUT - BLUE WATER BALANCE % OF VAPOR FLOW FARMER’S FIELDFARMER’S GREEN WATER LOSS GREEN WATER YIELD GAP VAPOR PERCOLATION BLUE WATER RAIN DEFICIENCY LOSSES RUNOFF BLUE WATER Rockström et(2007) al. FLOW GREEN GREEN WATER RESOURCE BLUE WATER RESOURCE HYDROLOGICAL LIMITATIONS GLOBAL PRODUCTION LOSSES LOSSES TOTAL CEREAL VS IRRIGATED CEREALS

GREEN WATER USE EXCLSIVELY?!

WATER PRODUCTIVITY

Sieber & Döll (2010) WATER PRODUCTIVITY FOOD, FIBER PRODUCTION VS WATER CONSUMPTION CULTURE TYPE m-3 kg-1 m-3 1.000 k cal-1 CEREALS 1,5 0,47 STARCHY 0,7 0,78 ROOTS 600 m3 SUGARCROPS 0,15 0,49 OILCROPS 2 0,73 WATER PRODUCTIVITY VS GRAIN YIELD VEGETABLE 2 0,23 OILS VEGETABLES 0,5 2,07 AVERAGE 1,14 0,5 EUCALYPTUS 0,6 MEAT 4 DAIRY >6 PRODUCTS VAPOR SHIFT !!!! WATER PRODUCTIVITY

WP= green WP m-3 t-1 (ET flow) WP= WP -3 -1 t WPt = productive green WP m t (T (1- ebY ) flow) b= constant (rate of decline in E) Y= grain yield (t ha-1)

ETo = reference (mm day-1) Δ= slope of vapor pressure curve (kPa 0 C-1 ) ϒ= psychrometric constant (kPa 0 C-1 ) Shuttleworth (1993) Rn= net radiation at crop surface (mm day-1 ) G= soil heat flux (mm day-1 ) SOIL – - ATMOSPHERE DELTA FLOWS

Δ1

Δ2 Δ

Δ3 DELTA FLOWS DAILY CHANGES

ROOT AGING

Nobel (2009)

DRYING DELTA FLOWS

Höfler-Thoday Diagram

Water Transport speed potencial gradient

Membrane

Water potencial (MPa) potencial Water hydraulic conductivity

Relative water content ɵ

Half-time (seconds) DELTA FLOWS

Water liters per day

SOIL ROOTS LEAFS ATMOSPHERE

MASS FLUX OR MASS FLUX DIFFUSION OSMOTIC

PUSHED OR PULLED

TAIZ & ZEIGER (2009) DELTA FLOWS

ANALOGY TO OHM’S LAW

DIFFERENCE BETWEEN ELECTRIC AL POTENCTAL FLUX RESISTANCES

VOLTAGE FLUX RESISTANCES DELTA FLOWS

[LEAF VAPOR] – [ATMOSPHERE VAPOR] TRANSPIRATION LEAF + AIR RESISTANCE

VPDLEAF-AIR TRANSPIRATION LEAF + AIR RESISTANCE

VPD HIGHEST GRADIENT SOIL-PLANT-ATMOSPHERE DELTA FLOWS

DIEL VDPLEAF-AIR FLUCTUATIONS

LEAF AIR

VDP

CVAPOR = CONSTANT

MOURNING AFTERNOON

DAY PERIOD TAIZ & ZEIGER (2009) DELTA FLOWS

STOMATAL ROUTE SHORT TERM REGULATION LEAF AIR

CUTICULAR ROUTE

R folha= (Rm + Re)(Rc) Rm+Re+Rc

CO2 vapor

vapor CO2 WATER DRIVING FORCE

vacuole cell wall cell membrane

chloroplast cytoplasm

CR P(Mpa)

Air Water surface tension Water film Air-water interface curvature radius (CR)

Cellulose microfiber DELTA FLOWS

ROOT LEAF XYLEM

LONGEST ROUTE

MASS FLUX IN CILINDERS

(VOLUME/TIME) DELTA FLOWS

“ AIR SEEDING”

EFFICIENCY

HOWEVER!!!!! V

TRACHEIDS VESSEL MEMBERS WATER MOVEMENT THROUGH

VULNERABILITY TO EMBOLISM LOSS HYDRAULIC CONDUCTANCE HYDRAULIC LOSS

XYLEM WATER POTENCIAL SOIL- ROOT INTERFACE

SOIL ROOT XYLEM

WATER POTENTIAL

TRANSPIRATION

MASS FLUX OSMOTIC FLUX SOIL- ROOT INTERFACE

Time )

Root superficial area

Soil - root delta pressure

Soil-root cylinder radius

Hydraulic conductivity Ʃ effects soil interface root

SOIL- ROOT INTERFACE

)

1

-

Mpa

1 -

soil soil

gap root COMPACTION?!

overall Hydraulic Hydraulic conductance or conductivity (ms Soil drying time (days) HYDRIC STRESS SITUATIONS LEADING TO LOW WATER AVAILABILITY

HIGH VDP HIGH EVAPOTRANSPIRATION SALINITY FREEZING

GROWTH

CELULAR EXPANSION RATE CELL WALL EXTENSIBILITY HYDRAULIC PRESSURE CELULAR EXPANSION CELL WALL THRESHOLD RATE HYDRAULIIC REDISTRIBUTION

HYDRAULIC REDISTRIBUTION WATER MOVEMENT FROM RELATIVELY MOIST TO DRY SOIL LAYERS USING PLANT ROOTS SYSTEMS AS CONDUITSDRY LAYER

WET LAYER

30 HYDRAULIC REDISTRIBUTION

• LABORATORY TRIALS – ROOTS EXPELLING WATER IN DRIER LAYERS • REDISTRIBUTIO OCCURS IN ALL DIRECTIONS- GRADIENT

1987 (RICHARD & CALDWELL)

31 PROCESS EFFICIENCY

14 – 33% DAILY EVAPOTRANSPIRATION

50% - 100 days year-1

ROOT ARQUITECTURE + ROOT LENGTH DENSITY

Acacia tortilis 32 GRAIN PRODUCTION

RAZÃO DE TRANSPIRAÇÃO = ÁGUA TRANSPIRADA/CO2 ASSIMILADO

ESPÉCIES RAZÃO DE TRANSPIRAÇÃO C 3 500 INTEGRATED C 4 250 SYSTEMS CAM 50

33 BIOIRRIGATION

RESISTANCE TO DRY SPELLS

34 “IS IT PROBLEMATIC, FROM A WATER RESOURCES PERSPECTIVE, IF PEOPLE USE CROPS PRODUCED WITH ALMOST EXCLUSIVELY GREEN WATER? MAYBE, IT IS NOT, UNLESS CROP PRODUCTION LEADS TO WATER POLLUTION”

Siebert (2010) THANK YOU !