What is the primary function of humus in soil?

Carbon becomes available in the crop plants in the form of:

Whiptail of cauliflower is due to

Control of weeds by weedicides in linseed is__

In British Drug House (BDH) method of pH testing, soil is mixed with distilled water, universal indictor solution and ______for a colour reaction.

Raphanus sativas L is the botanical name of:

“Brown heart” of turnips and “hollow stem” in brassicas is due to the deficiency of 

Aluminium Phosphide is used to control stored grain pest _____

Gemma cups are found in which plant?

Which of the following soil horizon is also known as the 'Zone of illuviation'?