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Overview of Hydroponics

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Consumption of tomatoes in the United States has reached 4.3 billion pounds each year. When consumers are willing to pay double or triple standard prices for a great tasting, blemish free product, buyers and sellers alike can smile at the possibilities. Repeated pricing studies have shown that only high-quality, garden vegetables, such as tomatoes, cucumbers, salad crops and culinary herbs, can provide break even or better revenues in hydroponic systems.

Hydroponics is a technology for growing plants in nutrient solutions (water and fertilizers) with or without the use of artificial medium (e.g., sand, gravel, vermiculite, rockwool, peat, coir, sawdust) to provide mechanical support. Liquid hydroponic systems have no other supporting medium for the plant roots: aggregate systems have a solid medium of support. Hydroponic systems are further categorized as open, where after the nutrient solution has been delivered to the plant roots, it is not reused; or closed where surplus solution is recovered, replenished, and recycled. The definition of hydroponics has been confined to liquid systems only, which blurs statistical data and leads to underestimation of the extent of the technology and its economic implications. All hydroponic systems in temperate regions of the world are enclosed in greenhouse-type structures to provide temperature control, reduce evaporative water loss, and to reduce disease and pest infestations.

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The principal advantages of hydroponic controlled environment agriculture (CEA) include high-density maximum crop yield, crop production where no suitable soil exists, a virtual indifference to ambient temperature and seasonality, more efficient use of water and fertilizers, minimal use of land area, and suitability for mechanization, disease and pest control. The major advantage of hydroponic (CEA) compared to field grown produce is the isolation of the crop from the soil, which often has problems of diseases, pests, salinity, poor structure and/or drainage.

The principal disadvantages of hydroponics, relative to conventional open-field agriculture, are the high costs of capital and energy inputs, and the high degree of management skills required for successful production. Capital costs may be especially excessive if the structures are artificially heated and cooled. This is why appropriate crops are limited to those with high economic value such as tomatoes.