A Simple Method to Design Irrigation Rate and Duration and Improve Water Use Efficiency

Abstract

Irrigated agriculture will have to increase production to meet the demand for food of the population of the world. A simple physically based method is presented that allows to determine appropriate irrigation rate and duration to avoid runoff, thus contributing to the design of efficient irrigation. The method relies on the infiltration capacity curve of the soil under interest. This curve allows determination of two important relationships: (a) maximal irrigation rate vs. irrigation dose and (b) irrigation duration versus rate. Two case studies illustrate the application of the method to adapt irrigation to the reduction of soil infiltration capacity resulting from the quality of the irrigation water (treated wastewater) or soil surface sealing. The range of irrigation rates for which duration can be estimated as the ratio between the required dose and the application rate is defined.

Mitigating the Impact of Irrigation With Effluent Water: Mixing With Freshwater and/or Adjusting Irrigation Management and Design

“…This can also be achieved by increasing the number of drippers per line (drippers every 25 cm instead at every 50 cm as it is done currently) or by using concentric loops of driplines around the trunk. The promising results described above are in agreement with the physically based analysis presented in Assouline (2019).…”

“…To support the required expansion of irrigated agriculture and to ensure its sustainability and profitability when WW is used for irrigation, we need to seek for approaches that mitigate the adverse impacts of water quality on soil properties and yields. For example, Assouline (2019) has presented a simple physically based method that relies on the infiltration capacity curve to adjust irrigation rate and duration to changes in soil infiltrability, thus contributing to the design of efficient irrigation.…”

Unique Relationship Between Rate and Cumulative Flow: A Property of Infiltration and Evaporation in Soils

“…For each soil, the information in q cap ( t ) can be used to estimate the ponding time that corresponds to each wetting rate (Figure 4c) (Assouline et al., 2007; Assouline, 2019). Similarly, e cap ( t ) can be used to estimate the duration of S1 for each soil and for each drying rate (Figure 4f).…”

What Can We Learn From the Water Retention Characteristic of a Soil Regarding Its Hydrological and Agricultural Functions? Review and Analysis of Actual Knowledge

“…The information is valuable as it presents the infiltration capacity curve characterizing each specific soil, and allows estimating runoff from any prescribed wetting rate (Assouline et al., 2007). It helps also in defining the respective wetting rates that prevent ponding and runoff formation, a key issue in the design of efficient irrigation (Assouline, 2019).…”

“…Information on the soil infiltration capacity, q cap , is valuable in terms of the hydrological response of soils. It is required to estimate ponding time; to evaluate runoff produced by a given wetting event (rainfall or irrigation); to reconstruct the infiltration curve for any given water application rate; and to prevent ponding during irrigation design (Assouline, 2019; Assouline et al., 2007; Brutsaert, 2005; Smith & Parlange, 1978). These are very important hydrological (natural rainfall) or agricultural (irrigation) elements of soil functioning.…”