Soil-less culture is generally called as hydroponics. here is some information about hydroponics ...........
What is hydroponics ? >
The term “hydro-ponics” comes from the Greek words for water and work. It literally means "let the water do the work". Modern applications began in 1930`s. Today, hydroponics commonly refers to growing plants without soil.
Plants do not necessarily need soil, they need mineral elements, water, air, light and warmth. In hydroponics the mineral elements are added to the water to form a nutrient solution which feeds the plants.
This technology has a tremendous future.
Someday most of our food may well be grown without soil. Thousands of commercial greenhouses around the world use hydroponic systems for growing tomatoes, lettuce and other vegetable crops. Many of those vegetables find their way onto our supermarket shelves.
There are two main categories of hydroponic systems
The active system uses a pump to irrigate the gardens, the passive depends on capillary action or wick absorption.
Passive systems are not recommended for larger areas. One can achieve good results with house-plants or small salad gardens. However, the rate of growth, ease of maintenance, and overall yield will be very disappointing in bigger gardens or if one is growing vegetables, such as tomatoes. Passive systems are great to start seeds, root cuttings and to get new seedlings going.
In active hydroponic systems a nutrient solution is pumped from a reservoir onto the plants. Most modern active systems recirculate the nutrient solution.
There are four main types of active systems:
Ebb and Flow
Nutrient film technique (NFT)
A submersible water pump pushes the nutrient solution from a central reservoir into irrigation tubes where it drips onto the growing medium, drains through it and returns to the main reservoir tank. The emitter regulates how much drips onto each plant. Drip irrigation can be used for commercial applications as well as for house plants.
Ebb and Flow
The nutrient solution is pumped from a central reservoir into the growing medium, temporarily flooding it. The pump is timed, then turned off in order to allow the solution to flow back into the reservoir. Normally a fewl short irrigation cycles are needed a day, more frequent flooding cycles are required on hot days or for large, fast-growing plants. The “ebb and flow” system is one of the easiest hydroponic methods to work with and is commonly used in large commercial installations.
Nutrient Film Technique (NFT)
NFT has gained quite some success among commercial greenhouse operators as well as among first-time home gardeners. The roots simply hang in a trough, through which a film of nutrient solution flows constantly. The plants can be supported from above, can be rooted in small plant cubes or can be grown through holes in the trough covering. Some NFT systems use small mesh pots filled with clay pellets to support the plants and to retain moisture around the roots which also avoids that the roots dry out.
The roots simply hang in the air or inside grow tunnels and are provided with a nutrient solution through a high power pump. There are a number of new systems on the market that provide excellent growth results.
When the system drains the clay pebbles do not compact. They are stable in shape and structure, allowing excess moisture to drain and fresh oxygen to sip in.
Due to the heavy construction and population the soil or land is limiting factor today. there is very small land holdling today we have. govt senerio for last yr tells that only avg. 1.5 ha. so there is trend like you said. soil less farming. soil less farming comparises media other than soil for growth there are different types used for farming. our ancent uses soil as growth medium for agriculture. like wise there are number of methods and media for production. of which one is explianed by Ashwini as water. and another you can use any material that can be easily available at your place and also having the growth property that means it should have some water holding capacity, microbial content, so you may use the wooden powder for growth. it can does well try it. and such useful items are in huge quantity in india.