Current approaches to assess land use and surface atmosphere interactions: Irrigation, salinity and drought Joop Kroes

COST718 Bologna, June 2005 Content River basin in India Polder in The Netherlands Irrigation and brackish water Conclusions

COST718 Bologna, June 2005 Research question Optimize water use and crop production Use of remote sensing Validity of procedures Sirsa district within Haryana state River basin in India

COST718 Bologna, June 2005 Methodology: Remote sensing Field experiments Scenario analysis: climate, salinity, water distribution, crop growth River basin in India

COST718 Bologna, June 2005 Results: Remote sensing for land use River basin in India

COST718 Bologna, June 2005 Results: Remote sensing for land use and ET-estimates Depends on irrigation (rainfall 20% of ET) Compared with modeling results River basin in India rabi (winter) seasonkharif (summer) season

COST718 Bologna, June 2005 Results: Water productivity (WP) a good performance indicator; relates productivity and water use, example: ‘crop per drop’ River basin in India

COST718 Bologna, June 2005 Results: Water productivity WP different crops and areas WP to communicate with stake holders (decision makers and water managers) Improve water distribution Minimize groundwater exploitation River basin in India Source: Singh, R (2005): Dissertation Wageningen-UR (

COST718 Bologna, June 2005 Polder in The Netherlands Problem urbanization climate change-> rising sea level Salinization of ground water and surface water impact on crops include irrigation

COST718 Bologna, June 2005 Polder in The Netherlands Possible solutions: Find locations for storage Balance the impact of climate and salinity on crops

COST718 Bologna, June 2005 Salt (Cl - ) tolerances applied in this study Polder in The Netherlands Crop Soil solution Potatoes 750mg/l Grass3600mg/l Forage maize 800mg/l Flower bulbs 150mg/l Irrigation water 200mg/l 950mg/l 200mg/l 50mg/l [Cl - ] in groundwater (mg l -1 )

COST718 Bologna, June 2005 Method: Land and surface water Waterinlet brackish water Climate scenarios: wet -> extreme dry year Polder in The Netherlands

COST718 Bologna, June 2005 Conclusions: Much water required for leaching of salts A need for alternatives: Alternative crops Find acceptable salinity ranges Polder in The Netherlands

COST718 Bologna, June 2005 Saline groundwater in The Netherlands Prediction of salinization increase in 2050 Source: /

COST718 Bologna, June 2005 Salinization in The Netherlands Prediction of salinization increase in 2050 Source: / predictions

COST718 Bologna, June 2005 Purpose: Analyze yield reductions when irrigated with brackish water Balance drought stress versus salinity stress from irrigating brackish water Irrigation with brackish water in The Netherlands

COST718 Bologna, June 2005 Method: Climate range Potato crop Loamy and clay soils Irrigated with gifts of 20 mm when soil is dry Irrigation with brackish water in The Netherlands

COST718 Bologna, June 2005 Results: Irrigation range: mm/jr Variation depends on climate, soil type and hydrological conditions Irrigation with brackish water in The Netherlands

COST718 Bologna, June 2005 Stoneplot 4807 ds-opbrengst Ca (kg/ha) nb A Stoneplot 5206 ds-opbrengst Ca (kg/ha) nb B Irrigation with brackish water in The Netherlands Results: salt stress << drought stress, even in dry years (like 1976) irrigation with high salinity levels (>1000 mg/l) is very well possible Fig: Yield versus time nb=not irrigated 0,1200,2400,5000 [Cl] of irrigation water (mg/l)

COST718 Bologna, June 2005 Irrigation with brackish water in The Netherlands Results: Relative yield decrease around 1500 mg l -1 Drought sensitive soils show rapid yield decrease Relative yield [Cl - ] irrigation water (mg l -1

COST718 Bologna, June 2005 India and Dutch polders: water with good quality is required to leach down salts and maintain proper yields Dutch polders: Irrigation with brackish water is possible Optimize instead of maximize yields, with more attention for extreme wet conditions Conclusions

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