Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

Abstract

Abstract. Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for fresh water. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET/Y). The management practices are: four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)); four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation); and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments; wet, normal and dry years; three soil types; and three crops. The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is: 8–10 % if we change from the reference to drip or SSD; 13 % when changing to OML; 17–18 % when moving to drip or SSD in combination with OML; and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow is lower.

Drought impacts to water footprints and virtual water transfers of the Central Valley of California

“…CET c , CE spg , and CE r are the seasonal cumulative crop evapotranspiration, cumulative effective seepage, and cumulative effective rainfall contribution, respectively [ Orang et al ., ]. CUP+ does not distinguish between E and T and does not incorporate capillary rise, unlike other ET models used to determine high‐resolution water footprints [ Chukalla et al ., ; Zhuo et al ., ]. However, depths to the water table are considerable in the Central Valley, so capillary rise is negligible for crop growth in this region.…”

Optimization of the Cropping Pattern of Main Cereals and Improving Water Productivity: Application of the Water Footprint Concept

“…Considering the fact that more than 90% of freshwater resources are consumed in the agricultural sector, one of the main strategies to alleviate water scarcity is to reduce agricultural water consumption (Chukalla et al ., ). Both rainfed and irrigated farming systems are common in Iran.…”

“…The concept of WF was first introduced by Hoekstra () and has been used in many studies in the field of freshwater resources management (Gerbens‐Leenes et al ., ; Aldaya and Hoekstra, ; Tian, ; Ababaei and Ramezani Etedali, ; Antonelli and Sartori, ; Chukalla et al ., ; Pahlow et al ., ; Schyns et al ., ; Wang et al ., ; Zhuo et al ., ; Ababaei and Ramezani Etedali, ). The WF is defined as the volume of consumed or polluted water for producing a product and it is calculated over its whole production chain.…”

“…using drip irrigation systems and reducing soil evaporation by applying mulches). There are several other ways to reduce the volume of WF, including optimizing planting dates and cropping patterns, lowering fertilizer loss, and more effective use of precipitation (Chukalla et al ., ; Zhuo et al ., ).…”

Using Regional Virtual Water Trade and Water Footprint Accounting for Optimizing Crop Patterns to Mitigate Water Crises in Dry Regions

“…Virtual water footprint (WF) and virtual water (VW) trade are promising concepts for sustainable management of groundwater and surface water resources, when there is no new source to meet the ever‐growing demand for water, especially in dry and semi‐dry regions (Gleick, ; Postel, ; Norse, ; Yang et al ., ; World Water Assessment Programme (WWAP), ; Mekonnen and Hoekstra, ). It has been suggested in the literature that VW trading can be an approach for saving water resources and to achieve water security at the regional, national and international level (Allan, ; Hoekstra, ; De Fraiture et al, ; Oki and Kanae, ; Yang et al ., ; Chapagain et al, ; Liu et al, ; Gerbens‐Leenes et al, ; Aldaya and Hoekstra, ; Tian, ; Antonelli and Sartori, ; Chukalla et al, ). A study on VW trade for produced and consumed products in three states New Jersey, Maryland and Delaware in the USA showed that water consumption would be reduced by 35% through VW trade management (Wang et al, ).…”