Give three reasons for using a soilless root substrate rather ...

[Deast7027]

Give three reasons for using a soilless root substrate rather than a soil-base substrate.
 
  What will be an ideal response?

Question 2

What are three sources of Ca and Mg in a greenhouse crop system?
 
  What will be an ideal response?

[robbielu01]

Answer to Question 1

1) If the proper components are selected, pasteurization of the
substrate can be eliminated. 2) Low densities are easily achieved in soilless
substrates. 3) The need for a continuous supply of uncontaminated, uniform soil is
averted.

Answer to Question 2

The water source, liming materials in the root substrate, fertilizers.