Air, water, and warmth are the conditions necessary for a plant to germinate. With the growth of urbanization, land has become scarce, and farmers are adapting to new farming methods. The purpose of a planting medium is to physically support the plant and to supply adequate oxygen, water, and nutrients for proper root functions.
With the new innovations in agriculture, farmers are now able to manipulate alternative media other than soil to grow their crops. Planting media components are either organic or inorganic. Organic components include wood chippings, sawdust, rice hulls, coconut husk fiber, among others. Inorganic components include perlite, pumice, vermiculite, starter plugs, hydrogel, among others.
The use of planting media has become a common practice more so in greenhouse farming, home gardens like pots, seedbeds, and planting trays. A farmer can choose to use the individual organic or inorganic media, mix organic media with soil, or organic media with inorganic media or inorganic media with soil to improve its germinating conditions.
The general structure of planting media varies . For example, sawdust has small particles with fine texture, perlite is generally coarse in nature with soil-like particles while starter plugs are generally a large spongy substance. There must be adequate small pore space to hold water for plant uptake and enough large pores to allow the exchange of air in the medium to maintain critical oxygen concentrations. The composition of a growing medium should be well-drained, low insoluble salts, and with an adequate exchange capacity.
A good planting media provides a reservoir for holding water and nutrients and provides an effective gaseous exchange system. Unlike soil, planting media does not supply plants with any nutrients so the farmer must provide them. Minerals, nutrients, bacteria, and fungus are artificially introduced to the planting media depending on the needs of the plant. This ensures only specific requirements are made available to the plants and largely assists in controlling crop diseases. The compact media also allows for good anchorage to the crop whereby roots are deeply embedded into the medium.
CHEMICAL COMPOSITION OF PLANTING MEDIA
The chemical composition and nutrients available to plants can be easily monitored and controlled by the use of planting media. This generally increases the average produce per unit area of input because the rate of transition from seed to crop is generally high and plants will grow into highly nutritious, strong, leafy, and healthy crops. This means that there will be enough food with a perfect nutrition balance to feed human beings.
The average pH for most plants to grow ranges between 5.2 and 6.2. Artificial planting media has a neutral pH but organic media are either acidic or base, depending on the media but that pH can be raised or lowered depending on the type of crops grown. The nature of planting media enables accurate monitoring of the pH level which can be easily regulated by use machines and chemicals. This provides favorable conditions for root development.
ADVANTAGES OF PLANTING MEDIA:
- A farmer achieves high yields in a limited area by applying a quality planting medium
- There is better control over irrigation, nutrition, and fertilization
- Compared to normal soil, the chemical composition and pH of planting media is easy to control
- There is a great reduction in the amount of water consumed and the drained water can be recycled
- The use of agrochemicals is greatly reduced
- Maximum utilization of space through vertical growing techniques
- Planting media is economical to buy, transport, and utilize
- Attack by diseases and weed infestation is greatly reduced
- Media require a small space to set up
- Easily manipulated to provide perfect conditions for growth