HYDROPONICS: GROWING PLANTS WITHOUT SOIL

 

Plants need sunlight, carbon dioxide (from the air), and mineral nutrients such as nitrogen and phosphorus. Traditionally, farmers have obtained these nutrients from soil. Hydroponics involves growing plants by exposing their roots to a nutrient-rich water solution instead of soil, usually inside of a greenhouse. Indoor hydroponic farming has a number of advantages over conventional outdoor growing systems:

• Crops can be grown indoors under controlled conditions almost anywhere.
• Yields and availability are increased because crops are grown year round, regardless of weather conditions. 
• In dense urban areas, crops can be grown on rooftops, underground with artificial lighting (as is now done in Tokyo, Japan), and on floating barges, thus requiring much less land.
• Fertilizer and water use are reduced through the recycling of nutrient and water solutions. There is no runoff of excess fertilizer into streams or other waterways.
• In the controlled greenhouse environment, there is little or no need for pesticides. There is no soil erosion or buildup of excess mineral salts (common problems on heavily irrigated cropland).

With these advantages, we could use hydroponics to produce an increasing amount of the world’s food without causing most of the serious harmful environmental effects of producing food through industrialized agriculture. However, there are three major reasons why this is not happening now. 

First, it takes a lot of money to establish such systems although they typically are cheaper to use in the long run.

Second, many growers fear that hydroponics requires substantial technical knowledge, while in reality it is very similar to traditional gardening and crop production. 

Third, it could threaten the profits of large and politically powerful industrialized companies that produce farming-related products such as pesticides, manufactured inorganic fertilizers, and farm equipment. 

Despite these obstacles to the use of hydroponics, large hydroponic facilities are found in a number of countries, including New Zealand, Germany, the Netherlands, and the United States. Hydroponics is unlikely to replace conventional industrialized agriculture. But a number of analysts project that, with further research and development, hydroponics could play an increasing role in helping us to make the transition to more sustainable agriculture over the next several decades.