Uncertainties in leaching assessment in micro-irrigated fields using water balance approach

Abstract

Leaching is an important aspect of irrigation water management, as it must be minimal to save available irrigation water resources, prevent shallow groundwater tables, and reduce nutrient loadings to the groundwater. However, at the same time, leaching should be sufficient to maintain root zone salinity levels below the threshold to prevent yield reduction. Therefore, monitoring leaching is the key component in evaluation and optimization of irrigation water management practices. Water balance (WB) is a common approach used to estimate leaching in agricultural fields and was applied in this study to assess field-scale leaching and the associated uncertainties for an almond orchard under drip and micro-sprinkler irrigation systems. In this study, we showed that change is soil water storage (ΔS) is highly influenced by the extent of monitoring depth, the location and number of monitoring points. Local measurement of WB parameters showed that leaching is highly variable across the field, thereby introducing considerable uncertainty on estimated leaching using WB approach. It was also shown that unknown input of water through fog interception added to the complexity of closing water balance at field scale.

Irrigation Intervals in the Production of Ornamental Pineapple in Pots1

“…Water depths greater than field capacity increase nutrient leaching in water-soluble fertilisers (JIA et al, 2014;MENDES et al, 2016) and should only be used to reduce an excess of salts in the root zone. Leaching, when adopted as an irrigation strategy, should use the minimum amount of water in order to save water resources and avoid environmental contamination (KISEKKA et al, 2019).…”

The production of ornamental pineapple in pots under different drip-irrigation depths

“…Leaching may be a necessary strategy to reduce excessive salts in the root zone. However, the amount of water used should be minimal to save water resources and avoid environmental contamination (Kisekka et al, 2019).…”

Improving Net Photosynthetic Rate and Rooting Depth of Grapevines Through a Novel Irrigation Strategy in a Semi-Arid Climate

“…For arid regions where the limited precipitation hardly supports grapevine growth, irrigation plays a significant role in offsetting the water deficit ( Alexandratos and Bruinsma, 2012 ; Fraga et al, 2018 ; Malek et al, 2018 ). In contrast, excessive and highly localized irrigation leads to soil hypoxia and salinity, excessive leaching, and increased energy use for pumping, which might also cause adverse effects on grapevine growth and production, groundwater contamination and a rapid decline in groundwater levels ( Drew, 1997 ; Scanlon et al, 2012 ; Kisekka et al, 2019 ; Zhang et al, 2020 ). Moreover, unstable climate patterns and increased demand of agricultural water for food production intensify the pressure on global water resources ( Mbow and Rosenzweig, 2019 ).…”