The development of intensive horticulture in Almería, with a huge increase in greenhouse surface area, is related to three essential factors: climatic characteristics, groundwater use and mulching sandy soil. The purpose of the present paper is to draw a picture of the integral management of water irrigation in the intensive horticultural systems in the region, by identifying the most significant water resource contributions and alternative water resources. Results indicate that the use of groundwater for the irrigation of horticultural crops in the greenhouses presents a high degree of overexploitation of the aquifers, but due to the continuous search for alternative water resources, such as desalinated and reclaimed water, as well as in-depth knowledge of the integral management of water irrigation through automated fertigation and localized irrigation systems, the current status of the water resources could be sustainable. Moreover, being conscious of the pollution generated by agricultural leachates, the horticultural system of Almería is implementing complementary sustainable systems such as recirculation, cascade cropping systems and phytodepuration for the reuse of the leachate. Considering all these factors, it can be concluded that the intensive horticultural system is on the right path towards respecting the environment and being sustainable in terms of water use.

Salvia officinalis L. is an aromatic and medicinal species that has medicinal and antioxidative properties. Studying the growth, productivity, and nutrient absorption of this plant under different water regimes is necessary to optimize its cropping techniques. Five irrigation regimes (100, 75, 50, 25, and 0% of ET₀) were tested in this trial, through two consecutive years, at two sites during the maximum water-demanding season (June–August period of 2003 and 2004), applied by drip irrigation. The effects of water regimes were tested under extreme climatic conditions (summer in Vega del Guadalquivir, Seville). Data were collected on dry-matter production, mineral nutrition, essential oil production, and the concentrations of bioelements in the airborne organs of the plant to determine the influence of water stress on these indexes. Results showed a significant effect of water regime on dry-matter production, essential oil content, and bioelement concentrations of the plant. Reduced irrigation (from 100% to 0% of ET₀) caused a decrease of the dry weight (73% of the commercial production of the plant), essential oil production (69%), and an increase of the nitrogen (N) content of the airborne organs of the plant (15%), together with a decrease of the levels of phosphorus (P), potassium (K), and magnesium (Mg) (21, 25, and 10%, respectively). These results confirm that S. officinalis production is limited by availability of water.

Developing an appropriate irrigation schedule is essential in order to save water while at the same time maintaining high crop yields. The standard procedures of the field evaluation of distribution uniformity do not take into account the effects of the filling and emptying phases of the irrigation system. We hypothesized that, in sloping sandy soils, when short drip irrigation pulses are applied it is important to take into account the total water applied from the beginning of irrigation until the emptying of the irrigation system. To compute distribution uniformity, we sought to characterize the filling, stable pressure, and emptying phases of a standard strawberry irrigation system. We found that the shorter the time of the irrigation pulse, the worse the distribution uniformity and the potential application efficiency or zero deficit are. This effect occurs because as the volume of water applied during filling and emptying phases increases, the values of the irrigation performance indicators decrease. Including filling and emptying phases as causes of non-uniformity has practical implications for the management of drip irrigation systems in sloping sandy soils.

The objective of this study was to evaluate the effects of two irrigation water qualities and three different levels of nitrogen–phosphorous–potassium (NPK) rates applied by fertigation on yield and quality of tomato fruit. The experiment was carried out in a polyethylene greenhouse on ‘Pitenza’ tomato grown on a sand‐mulched sandy loam soil using a trickle irrigation system. The treatment consisted of two irrigation water qualities (C₂S₁ and C₃S₂) and three fertilization levels: 50%, 100%, and 200% [7.1 mmol L⁻¹ nitrate (NO₃) N, 0.5 mmol L⁻¹ P, and 3.1 mmol L⁻¹ K] for each water quality category. The dry‐matter content of fruit (DMC), number of fruit, fruit weight per period (g), weight per fruit (g), number of trusses, fruits per truss, and unmarketable fruit were monitored. Quality was evaluated using fruit firmness (Kg), total soluble solids (°Brix), pH, and tritable acidity (meq citric acid L⁻¹ of juice). The increased salinity of the irrigation water did not affect the marketable and unmarketable yield of fruit but did produce an increase in the number of fruits per truss at 127 days after transplanting (DAT) (10%) and in the DMC percentage at 127 and 179 DAT, being 9 and 6.8% respectively. High‐salinity irrigation water reduced the firmness of the fruit at 127 and 179 DAT (9% and 22%, respectively); it increased the soluble solids for all the dates analyzed as well as the fruit's tritable acidity with significant differences at 127 and 206 DAT. The fertilization level increased the marketable yields, fruit number, and number of trusses during all stages. Treatment F₁ produced a yield 28% lower than F₂, whereas F₃ was 10% higher than F₂. The results show that irrigation water electrical conductivity (EC) of 2.2 dS m⁻¹ is adequate for high yield and quality of tomato in the commercial cycle.

The aim of this work is to evaluate the relationship between the nutrient concentration in petiole sap and different agronomic and climatic variables for a tomato crop grown in a greenhouse in Mediterranean conditions. In addition, the persistence of the nutrient concentration in petiole sap was investigated with the aim of determining the sampling period that implies the best trade-off nutritional information. The experiment consisted of the selection of 20 sampling points inside the greenhouse. The samples of petiole, fully expanded leaf, and soil solution samples were collected weekly from 86 to 163 days after transplanting. Chloride, NO₃⁻-N, H₂PO₄⁻-P, Na⁺, K⁺, Ca²⁺, and Mg²⁺ concentrations were determined in petiole sap and soil solution obtained by suction cups. Nitrogen, P, K, Cl, and Na concentrations were also determined in leaf. Finally, the petiole sap nutritional diagnosis method is the highest sensitive nutritional diagnosis method which compares soil solution and nutrient leaf content related to yield, and the statistical analysis performed in this research demonstrates that crop evapotranspiration (ETc), vapor pressure deficit (DPV), and leaf area index (LAI) are considered the most significant variables that allow the development of these empirical prediction models regarding nutrient concentration in petiole sap.