Based on a new structure for plastic culture channels, a new system for soilless culture called New Growing Systems (NGS) has been developed. It is similar to the nutrient film technique (NFT) but with several potential advantages. Each NGS growing channel has five plastic layers and a large number of holes, there is a dripper every 0.5 m above the first layer of plastic, and each dripper supplies the nutrient solution which flows from the second layer over the others to the end. Three separate greenhouse experiments with tomato, cucumber, and sweet pepper using NGS channels were conducted in Almería (southeastern Spain). The oxygen content in the circulating nutrient solutions was determined at different points and different times along the channels of all crops. Depletion of oxygen content in the nutrient solution was lower than NFT channels. Oxygen content in NGS showed some advantages compared to NFT.
of saffron crop and point of sample temperature under soilless culture. Fertigation management was carried out according to the methodology proposed by Urrestarazu et al. (2015 ). The application of new fertigation was effected when the water in
, nutrient concentrations are sometimes higher than necessary for optimum plant growth and yield, and there is limited information about the effects of increased EC nutrient solution management in soilless culture. Hence, this work aims to assess the effects
Aeroponics, as a method of soilless culture, has been in intermittent use since the 1950's. Early Russian and Italian research suggested that productivity and use of space was optimized with this technique. Prior to the introduction of ultrasonic techniques, aeroponics utilized spray nozzles or spinning disks. In addition to the need for frequent cleaning, the first results in the formation of a boundary layer on the root surface, similar to that formed in hydroponics, which results in nutrient and aeration gradients. The second results in significant physical disturbance to the root system and, except under very controlled conditions, also develops a boundary layer. Ultrasonic fogs avoid these side effects and allow the use of carbon dioxide enrichment of the root zone as well as reduced nutrient concentrations. Initial results with commercially available equipment are very promising. Commercial implementations of ultrasonic aeroponics promise to be far less energy and manpower intensive than any other method of plant culture. Lettuce, corn, tomato, soybean, dry bean, and geraniums have all been cultured with this method.
, D. 2012 Algunos usos de la visión artificial y su aplicación en la horticultura protegida Vida Rural 343 46 48 Fernández-Bregón, N. Valera, D. Urrestarazu, M. 2013 Uniformity of fertigation as diagnosed by infrared thermography under soilless culture
The financial effectiveness of the soilless culture system (SCS) of gerbera (Gerbera jamesonii Bol. ex Adlam.) production was compared with that of the soil culture system in heated greenhouses in northern Greece. Evaluation was based on budgeting procedures that assumed a project life of 9 years. The decision to accept or to reject the investment was based on the following criteria: 1) net present value analysis (U.S. $18,414), 2) benefit/cost ratio, and 3) risk exposure ratio. The soilless culture system, particularly the plastic bag system using perlite media, was more profitable. Application of sensitivity analysis illustrated the significance of product price and discount rate in determining the accrued benefits.
al., 2004 ; Romero et al., 2004 ; Van Hooijdonk et al., 2004 ). However, there has been little attention paid to application timing of nutrient solution for sweet pepper in soilless culture. Russo (2011) conducted research on irrigation timing in
The financial effectiveness of a soilless vertical bag system of hydroponics culture was evaluated for off-season strawberry (Fragaria ×ananassa Duch) production in heated greenhouses in northern Greece. Financial analysis revealed that the implementation of this soilless culture system instead of the traditional production system under plastic tunnels would not be profitable for Greek farmers due to its high initial investment and high fuel consumption. Sensitivity analysis indicated the importance of product price in affecting the magnitude of benefits, confirming the interest of farmers to produce off-season strawberries to market them when prices are likely to be higher. In addition, yield increase will have a positive effect upon farmers' income.
widely dispersed such as rockwool, perlite, or coconut fiber, which occupy areas of ≈5000 to 5500 ha ( Urrestarazu, 2013 ). Table 1. Variation in some characteristics of pozzolans (volcanic rocks) used in soilless culture systems worldwide. Currently, the
A greenhouse experiment was carried out to determine the effect of cationic proportions (K, Ca, Mg) in the nutrient solution on carotenoids and α-tocopherol content at green–orange, orange, red, and intense-red ripening stages using a high-pigment tomato (Lycopersicon esculentum Mill.) cultivar hp (`Lunarossa') and a standard cultivar (`Corfù') grown in a soilless culture. The highest lycopene concentration was observed in the `hp' cultivar at the red and intense-red ripening stages (3.0 mg/100 g fresh weight and 3.2 mg/100 g fresh weight respectively). In both cultivars, the concentration of β-carotene increased during the ripening stages, reaching the highest value (0.6 mg/100 g fresh weight) at the intense-red stage. The hp cultivar has guaranteed higher lycopene (average, 2.0 mg/100 g fresh weight vs. 1.7 mg/100 g fresh weight) and α-tocopherol contents (average, 1.2 mg/100 g fresh weight vs. 0.9 mg/100 g fresh weight) than those of the standard. In both cultivars, a high proportion of K in the nutrient solution increased antioxidant concentration β-carotene and especially lycopene) during the red and intense-red ripening stages, followed by Mg. The lowest values were recorded for the Ca treatment. Lastly, a positive correlation was recorded between fruit tissue K and lycopene content, whereas a negative correlation was observed between fruit tissue Ca and lycopene content.