Best practices on irrigation

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Best practices on irrigation Daniele Massa and Alberto Pardossi CRAVIV Best practices in

Cultivated area (rainfed + irrigated) = 1,500 q Irrigated area = 300 (20%) q Irrigated area

Research Centre and DirectorateGeneral for Environment jrciptsemas@ec.europa.

regarded as stating an official position of the European Commission.

responsible for the use which might be made of this presentation.

aspects q Seasonal/annual irrigation water use: Field crops: 300 (e.g. beans) to 1200 mm (e.g. cotton) Protected crops (per year): 600 (e.

) Higher in soilless culture (openloop hydroponics) than in soil q Tendency to overirrigate

(due to waterlogging and hypoxia in the root zone) increased susceptibility to root diseases F

1 Best practices on irrigation Daniele Massa and Alberto Pardossi CRAVIV Best practices in improving the sustainability of agriculture Global agriculture and water use (ha x 10 6 ) q Cultivated area (rainfed + irrigated) = 1,500 q Irrigated area = 300 (20%) q Irrigated area for food production = % q Irrigated area with salinity = % EXPO Milan, 6 July 2015 Joint Research Centre and DirectorateGeneral for Environment jrciptsemas@ec.europa.eu The views expressed are purely those of the authors and may not in any circumstances be regarded as stating an official position of the European Commission. Neither the European Commission nor any person action on behalf of the Commission is responsible for the use which might be made of this presentation. <1700 m 3 /capita/year <1000 m 3 /capita/year 2/23 Water use efficiency (WUE) 1, General aspects q Seasonal/annual irrigation water use: Field crops: 300 (e.g. beans) to 1200 mm (e.g. cotton) Protected crops (per year): 600 (e.g. leafy vegs.) to 1500 (fruit vegs.) Higher in soilless culture (openloop hydroponics) than in soil q Tendency to overirrigate (+10 to +50%) results in: water loss nutrient loss (with drainage water) and pollution (e.g. nitrates) increased production costs (energy for pumping, fertilisers, ) crop water stress (due to waterlogging and hypoxia in the root zone) increased susceptibility to root diseases F 3/23 1 mm = 1 L m 2 = 1 kg m 2 = 10 m 3 ha 1 I (mm); Y (t/ha) 1, Open field Yield WUE Irrigation volume Unheated plastic tunnel Unheated greenhouse Irrigation management & growing technology Heated Heated soilless greenhouse greenhouse (closed cycle) WUE (kg/m 3 ) 4/23

Key elements of the BEMPs on irrigation q Crop selection

Closedloop irrigation systems (substrate culture) q

Irrigation systems (drip vs overhead irrigation) Approaches

Irrigation (RDI) DEFICIT IRRIGATION Partial root drying (PRD)

2 Key elements of the BEMPs on irrigation q Crop selection (species and cultivars) q Soil management (tillage, amendments, etc.) q Water treatment and storage (desalinization, etc.) q Deficit irrigation (partial root drying, regulated d.i. ) q Closedloop irrigation systems (substrate culture) q Irrigation scheduling (ET models vs soil moisture sensors) q Irrigation systems (drip vs overhead irrigation) Approaches to efficient irrigation: Deficit irrigation Regulated deficit Irrigation (RDI) DEFICIT IRRIGATION Partial root drying (PRD) 5/23 6/23 Deficit irrigation Deficit irrigation 100 Net photosynthesis Expansion growth Y leaf (MPa) 7/23 8/23

Approaches to efficient irrigation Open vs closed irrigation systems Groundwater

25 kg/m 2 ) Water = 8,630 m 3 /ha N = 1,600 kg/ha (N) Water = 6,950 m 3 /ha N =

Sector 1 Sector 2 Disinfection unit Drain water Water = 1,680 m 3 /ha N= 270 kg/ha N

Soillessgrown tomato: water and N balance) (Tuscany; 2 crops/year; yield @ 25 kg/m 2

Approaches to efficient irrigation Irrigation scheduling Irrigation timers (the

) Determination of soil water balance (called ETbased method in greenhouse and

3 Approaches to efficient irrigation Open vs closed irrigation systems Groundwater Rainwater Soillessgrown tomato: water and N balance) (Tuscany; 2 crops/year; 25 kg/m 2 ) Water = 8,630 m 3 /ha N = 1,600 kg/ha (N) Water = 6,950 m 3 /ha N = 1,330 kg (N) Mixer Sector 3 Raw water tank Fertigation strategy Daystorage tank Sector 1 Sector 2 Disinfection unit Drain water Water = 1,680 m 3 /ha N= 270 kg/ha N (17%) Storage tank Daystorage tank 21/70 9/23 Source: Incrocci, /23 Soillessgrown tomato: water and N balance) (Tuscany; 2 crops/year; 25 kg/m 2 ) Water = 6,950 m 3 /ha N = 1,330 kg/ha (N) Water = 6,950 m 3 /ha N = 1,330 kg (N) Approaches to efficient irrigation Irrigation scheduling Irrigation timers (the standard method?) Determination of soil water balance (called ETbased method in greenhouse and nursery crops) Direct measurement of moisture content in the root zone with soil moisture sensors (SMS) Integration of methods 2 and 3 Speakingplant Water = 0 m 3 /ha N= 0 kg/ha N 11/23 12/23

14 47 Irrigation scheduling (dose and frequency) 1) Determination of available water in the root zone Leaf

system ET (mm) Root depth Texture Allowable water deficit (AWD, mm) Soilqq Frequency (time) Salinity (EC)

efficiency & uniformity Dose = AWD K S Driving factor ET based IS RZS based IS % volume 100 80 60 20 0 56

water (UW) Solid phase Volume of media explored by the crop roots Soil: 250 to 500 L m 2 (mm) depending on

Determination of the evapotranspiration rate 100 90 80 70 60 50 30 20 10 0 SUBSTRATE Volume (%) Air capacity

1) ET model: FAO equation. (http://www.fao.org/docrep/x0490e/x0490e00.

4 14 47 Irrigation scheduling (dose and frequency) 1) Determination of available water in the root zone Leaf area index (LAI) Climate Crop Soil Water Irr. system ET (mm) Root depth Texture Allowable water deficit (AWD, mm) Soilqq Frequency (time) Salinity (EC) Scheduling Coefficient (K S ) Dose (mm) I. efficiency & uniformity Dose = AWD K S Driving factor ET based IS RZS based IS % volume Soil Soil /substrate hydrology Soilless Air phase Easily Available Water (EAW) Unavailable water (UW) Solid phase Volume of media explored by the crop roots Soil: 250 to 500 L m 2 (mm) depending on root depth Soilless: 10 to 50 L m 2 (mm) 13/23 14/23 1) Determination of available water in the root zone 2) Determination of the evapotranspiration rate SUBSTRATE Volume (%) Air capacity Easily available water WATER AIR Total available water SOLID FASE ) ET model: FAO equation. ( ET = k c ET 0 K c : crop coefficient (ET/ETP). It incorporates crop characteristics and averaged effects of soil evaporation. ET 0 : reference or potential ET. It is assessed with evaporation pan or based on weather conditions. SOIL 300 1,000 15,000 Tension (hpa = cm of H 2 O) 15/23 16/23

2) Determination of the evapotranspiration rate 2.

2) ET model: semplified model for greenhouse.

depends basically on leaf area (LAI), the intercepted radiation (I c ), air

(VPD) Stomata regulation of leaf T is often limited (due to poor gh.

4 0.3 0.2 0.1 Y = 0.974 X 0.001 R 2 = 0.936 SEE = 0.023 kg m 2 h 1 MAPE = 15.9% % 0.

in greenhouse gerbera grown in substrate culture in different seasons (autumn, filled

Transpiration was simulated using the PenmanMonteith equation or its simplified

, 2013) 18/23 Predicted values (E d, kg m 2 h 1 ) 0.5 0.4 0.3 0.2 0.1 Y = 0.957 X + 0.

5 2) Determination of the evapotranspiration rate 2.2) ET model: plant transpiration under greenhouse. 2) Determination of the evapotranspiration rate 2.2) ET model: semplified model for greenhouse. PM equation Simplified equation ET is mostly determined by leaf transpiration (T) T depends basically on leaf area (LAI), the intercepted radiation (I c ), air temperature and relative humidity, which both determine the vapour pressure deficit (VPD) Stomata regulation of leaf T is often limited (due to poor gh. ventilation) I T = A c + B LAI VPD l 17/23 Predicted values (E d, kg m 2 h 1 ) Y = X R 2 = SEE = kg m 2 h 1 MAPE = 15.9% % Measured values (E d, kg m 2 h 1 ) Relationship between simulated and measured values of diurnal transpiration (E d ) in greenhouse gerbera grown in substrate culture in different seasons (autumn, filled symbols; spring, empty symbols). Transpiration was simulated using the PenmanMonteith equation or its simplified version (regression model). (Carmassi et al., 2013) 18/23 Predicted values (E d, kg m 2 h 1 ) Y = X R 2 = SEE = kg m 2 h 1 MAPE = 15.5% % Measured values (E d, kg m 2 h 1 ) DIRECT MESUREMENT OF SOIL MOISTURE WATER BALANCE PLANT GROWTH DATALOGGERS 3) Direct measurement of waterrelated parameters in the root zone CLIMATE PARAMETERS TDR (Time Domain Reflectometry) IRRIGATION RIGATI SYSTEM MANAGEMENT FDR (Frequency Domain Reflectometry) 19/23 20/23

$q Irrigation is generally inefficient due to: empiricism in irrigation scheduling, use of saline water (large leaching fraction), etc.$ q Overirrigation causes pollution due to the leaching of agrochemicals (e.g. nitrates, phosphates, plant protection products), soil erosion, etc. www.fao.org www.

q Overirrigation causes pollution due to the leaching of agrochemicals (e.g. nitrates, phosphates, plant protection products), soil erosion, etc. www.fao.org www.

q Advanced irrigation management (application of crop modelling and/or sensing technology, deficit irrigation) q Reuse of drainage water (closed system) q Use of drip

6 Approaches to efficient irrigation Irrigation systems: drip vs overhead irrigation Conclusions on BEMPs Why? q Irrigation is generally inefficient due to: empiricism in irrigation scheduling, use of saline water (large leaching fraction), etc. q Overirrigation causes pollution due to the leaching of agrochemicals (e.g. nitrates, phosphates, plant protection products), soil erosion, etc. What? q Advanced irrigation management (application of crop modelling and/or sensing technology, deficit irrigation) q Reuse of drainage water (closed system) q Use of drip irrigation q Other measures (crop selection, water treatment) Up to 100% distribution efficiency.especially 21/23 How? q Regulations q Dissemination of best practices q Education and training 22/23 Thank you! European Commission: Joint Research Centre and DirectorateGeneral for Environment jrciptsemas@ec.europa.eu Websites:

Developing and Integrating Plant Models for Predictive Irrigation

Developing and Integrating Plant Models for Predictive Irrigation Jongyun Kim Post-Doctoral Research Associate Department of Plant Science and Landscape Architecture University of Maryland, College Park,