In hydroponic vegetables,the $pH$ preferred by most vegetables is slightly

The possible resource of phosphorus ions and nitrogen ions in soil generally get depleted because they are usually found as

Those fertilizers,which provide all the essential elements such as $N, P$ and $K$ etc. required for plant growth,are called

The $pH$ of a fertile soil is usually around

Humus is important for plant growth because

Addition of a chelating agent to hydroponics is necessary for: