Methods to Study Mineral Requirements of Plants
In 1860, German botanist, Julius von Sachs, has demonstrated for the first time, that plants can grow to maturity in a defined nutrient solution without soil.
The balanced nutrient solution that is having all essential elements in proper proportions, used in experiments. This technique of growing plants in a nutrient solution is known as hydroponics.
Later, number of improvised methods have been employed to determine essential mineral nutrients for the plants. these methods to study the mineral requirement of plants are as follows:
Hydroponics
Sand culture
Aeroponics
Hydroponics
Solution culture is a technique in which plants are grown from seeds to maturity in a proper nutrient solution in the absence of soil. The growth of plants in this manner is known as soil-less growth or hydroponics growth.
It has many applications as hydroponics is used in the commercial production of some greenhouse crops like vegetables such as tomato, seedless cucumber and lettuce.
The conditions required for the optimum growth of plants are as follows:
The solution should be properly aerated for the growth and activities of roots.
The concentration of mineral nutrients should be maintained at regular intervals.
The pH of the solution should be maintained at regular intervals.
The experiments are done in controlled environments to observe the growth of plants.
Nutrient film technique
The plants getting growth in a tube or trough placed on a slight incline.
The pump circulates a nutrient solution from a reservoir to the elevated end of the tube.
The solution flows down the tube and returns to the reservoir due to gravity.
The arrows indicates the direction of the flow and this system provides good aeration to not only the roots and nutrient uptake but also the pH and nutrient to be adjusted and monitored.
Sand Cultures
In the case of sand culture, the plants are getting growth in the sand which is supplied with nutrient solution. The big vessels are used that filles with sand.
The sand used in this process is washed with acid and distilled water and Then nutrient solution is then added to the sand in regular intervals of time. The advantage of this technique is that the roots of plants are properly aerated.
Aeroponics
In the case of aeroponics technique, the roots are suspended in the air over the nutrient solution which is whipped into a nutrient mist by a motor-driven rotor.
the rooted plants are placed in a special box where the shoots of the rooted plants are exposed to air and roots kept inside the box with a controlled environment.
In short interval, roots are sprayed with a nutrient solution.
The high level of oxygen available at the roots promotes the growth of microbes that digest the nutrient and makes them easily accessible to the plants.
This is a recent method for the growth of plants. This technique used for citrus plants and olives.