Water Efficiency Archives

2019 Spain

Yield and fruit quality of avocado trees under different regimes of water supply in the subtropical coast of Spain

Authors: Moreno-Ortega, G.; Pliego, C.; Sarmiento, D.; Barceló, A.; Martínez-Ferri, E.

The subtropical Mediterranean climate of southeastern Andalusian coast allows Spain to be the largest European producer of subtropical fruit, with the avocado as the main representative. In this region, precipitations are scarce and erratic and limit water availability for irrigation. Under this climatic uncertainty, appropriate water use is required for assuring crop environmental sustainability and increasing water productivity (WP) of avocado orchards. For this purpose, it is necessary to evaluate

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2020 Israel

Mitigating negative effects of long-term treated wastewater application via soil and irrigation manipulations: Sap flow and water relations of avocado trees (Persea americana Mill.)

Authors: Nemera, D.B.; Bar-Tal, A.; Levy, G.; Lukyanov, V.; Tarchitzky, J.; Paudel. I.; Cohen, S.

Recent studies have shown significant negative effects of long-term irrigation with treated wastewater (TWW) on performance of orchards planted on clay soil. The aim of this study was to evaluate water use and water relations of different mitigation measures to remedy the declining performance of a mature commercial fruit-bearing 'Hass' avocado orchard (Persea americana Mill.) growing in a clay soil irrigated with TWW since 2009. The mitigation measures, each in 6 replicates, included freshwater

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2021 Israel

Mitigating negative effects of long-term treated wastewater irrigation: Leaf gas exchange and water use efficiency response of avocado trees (Persea americana Mill.)

Authors: Nemera, D.B.; Bar-Tal, A.; Levy, G.; Tarchitzky, J.; Rog, I.; Klein, T.; Cohen, S.

Declining performance of avocado orchards growing in a clayey soil irrigated with treated wastewater (TWW) for more than 5 years has been observed in Israel. Measures studied to mitigate this were freshwater (FW), blended TWW:FW in a 1:1 ratio (MIX), low-frequency TWW-irrigation (LFI), TWW irrigated tuff trenches (TUF) and TWW as the control treatment. This study reports on the response of avocado leaf gas exchange, intrinsic water use efficiency, leaf water potential and leaf hydraulic conductance

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2011 Chile

Soil moisture profiles under different conditions associated with irrigation efficiency of drip irrigation - case studies from avocado and mandarin, Limari River Valley

Authors: Osorio; A.; Cortes; M.; Rypowski; K.; Burgos; M.

Six tests were done to evaluate the application of irrigation rates in Limarí River Valley (30°36’ South Latitude 71°12’ West Longitude and 218 m of altitude) in avocado and mandarin tree orchards during two agricultural seasons. Assessments were made in volumes of water applied, discharge of the drippers and irrigation frequency used. Also, the water stored in the soil profile was monitored by moisture direct sampling with drill, performed deeply and transversely to the drip lines and plantation

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2007 California

Salinity and water effects on 'Hass' avocado yields

Authors: Oster, J.; Stottlmyer, D.E.; Arpaia, M.L.

A field experiment was conducted between 1992 and 1997 in a commercial orchard of mature 'Hass' avocados on Mexican seedling rootstock (Persea antericana Mill.) to determine how yield was influenced by the amount of irrigation water applied and the frequency of application. Three amounts of water (targeted at 90%, 110%, and 130% of estimated crop evapotranspiration) were applied at three frequencies (one, twice, and seven times per week) with microsprinklers located beneath the tree canopy. The site was set up as a randomized complete block design with six blocks, each including one replicate of all irrigation treatments. One or two trees located at the center of the replicates were used to measure yields and tree size, and as the locations where samples of soil and soil water were obtained for analysis from beneath the tree canopy. The average electrical conductivity and chloride concentration of the irrigation water, corrected for rain, were 0.7 dS(.)m(-1) and 1.8 mmol(.)L(-1), respectively. From May 1994 to Nov. 1996, salinity of the saturated-paste extracts of soil samples obtained in the 0- to 120-cm depth interval averaged approximate to 2 dS(.)m(-1) for all irrigation treatments. Irrigation treatments also had little influence on the maximum soil-water salinity, approximate to 4 dS(.)m(-1), in and below the lower portion of the root zone. Consequently, irrigation treatments had little influence on the fraction of applied water that was not used by the crop, the leaching fraction. Chloride concentrations in leaves were affected by applied water but did not attain levels that are associated with leaf injury. Trees irrigated seven times per week had lower yields than trees that received less frequent irrigation. During the last 2 years of the experiment, when yields no longer increased with time, the yields for treatments irrigated once and twice per week increased with increasing amounts of applied water. We were able to explain the influence of both amount of applied water and soil salinity on avocado yields and leaching fraction using production function concepts. Yields increased with increasing amounts of applied water because of increased water availability for crop use before a soil-water salinity, of approximate to 4 dS(.)m(-1) restricted water uptake. The threshold salinity above which yield decline occurred was determined to be 0.57 dS(.)m(-1) and yield declined by 65% per unit of salinity above the threshold. Our results suggest that maximum yields of 'Hass' avocado on Mexican seedling rootstock are not achievable when the average annual salinity, of irrigation water, including rainfall, is greater than approximate to 0.6 dS(.)m(-1).

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2020 California

Use of alternative water sources in irrigation: potential scales, costs, and environmental impacts in California

Authors: Qin, Y.; Horvath, A.

Under the risk of drought, unreliable water supplies, and growing water demand, there is a growing need worldwide to explore alternative water sources to meet the demand for irrigation in agriculture and other outdoor activities. This paper estimates stocks, production capacities, economic costs, energy implications, and greenhouse gas (GHG) emissions associated with recycled water, desalinated brackish and seawater, and stormwater in California, the largest US state and the most significant fresh

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