Shading Nets Usefulness for Water Saving on Citrus Orchards under Different Irrigation Doses

Abstract

Water uptake for agriculture is very intensive in Souss Massa region (521Mm 3 per year), where irrigation waters are almost exclusively pumped from the water table which is being depleted by 2 to 3 meter per year 1 . The climate is very arid with rainfall of about 150-200 mm/year concentrated in winter and Evapotranspiration (ETo) of 1800 mm/year with more than 7 mm/day in the Summer, average winter temperatures can reach 5-7°C whereas average summer temperatures can be as high as 32-36 °C 2-3 . Adding the effect of the foreseen climate change, the available water volumes are expected to shrink by 10-15% of the actual volumes in 2020 due to the falling groundwater levels and the reduction of the storage capacity of dammed lakes by siltation 4 . The citrus sector in the Souss region occupies about 33 000 ha which represents about 40% of the

Innovative Soil Management and Micro-Climate Modulation for Saving Water in Peach Orchards

“…If adequately managed, the canopy covering regulates the atmosphere water demand (Pirkner et al, 2014) in order to reduce water to be supplied through irrigation (Rana et al, 2004;Lopez et al, 2018). Orchard covering by shading hail net has been proposed as a technique to improve tree water status and water use efficiency where water is scarce (Nicolas et al, 2005;Corelli-Grappadelli and Lakso, 2007;Losciale et al, 2011;Abouatallah et al, 2012;Girona et al, 2012;Lopez et al, 2018).…”

“…Although some researches have analyzed the effects of shading hail net ( Corelli-Grappadelli and Lakso, 2007 ; Losciale et al., 2011 ; Abouatallah et al., 2012 ; Esmail et al., 2017 ; Lopez et al., 2018 ) or of mulching ( Wang H. et al, 2015 ; Wang C. et al, 2015 ; Lepaja et al., 2016 ) on the relationship between yield and soil water stress, no study has been designed expressly to determine the suitability of shading hail net in addition to mulching in attenuating the water stress induced by the DI technique at the soil level.…”

Effect of shading and water stress on light interception, physiology and yield of apple trees

“…Net shading has been proposed as a technique to improve tree water status and water use efficiency when water is scarce (Nicolas et al, 2005;Girona et al, 2012;Abouatallah et al, 2012;Esmail et al, 2017;Qi et al, 2017). Although the improvement in plant water status produced a positive effect on leaf photosynthesis in shaded trees grown under water stress conditions (Nicolas et al, 2005), net shading may still have a negative impact on fruit growth capacity because it reduces the amount of light intercepted by the tree (Girona et al, 2012).…”

“…It is well known that light availability is a primary factor affecting fruit growth (Jackson and Palmer, 1972) and orchard productivity is in general linearly related with the amount of light intercepted by the tree (Giuliani et al, 1998;Rosati and DeJong, 2003). However, all these studies considered the increase of light interception because of the increase of photosynthetically active surface, but limited research has been performed on the effect of modulation of light irradiance on productivity (Raveh et al, 2003;Losciale et al, 2010;Abouatallah et al, 2012;Esmail et al, 2017). Although some research evaluated the combined effects of water stress and net shading on yield in fruit trees (Abouatallah et al, 2012;Esmail et al, 2017), no study has been designed to determine the suitability of net shading as a drought mitigation technique when irrigation availability is lower than the crop water demand.…”

A new methodology to assess the maximum irrigation rates at catchment scale using geostatistics and GIS

“…Given the lack of data, the aforementioned land use map implemented in a GIS containing detailed information regarding the crops and irrigation system (surface or drip), as well as other specific information for citrus orchards, including plant spacing and plant age (Citrus-GIS, Generalitat Valenciana), was included in the geographic database of the study area. The wetting depth (d) was assumed to be 0.6 m for vegetables, in agreement with Thorup-Kristensen (2001) who indicated a range of rooting depths between 0.3 and 1 m. Because the rooting depth for citrus can be highly variable depending on the variety, irrigation system or soil properties, we assumed an average depth of 0.60 m for young trees and 0.85 m for adult trees, which was within the range indicated by Abouatallah et al (2012).…”