Agronomy is the science and technology of producing and using plants for food, fuel, fiber and land reclamation.

Hydrogen is the correct answer as it is among the 16 essential plant nutrients that are obtained by plants through water. It is a non-mineral nutrient.

Fodder is the correct answer. Fodder is grown to feed animals. So, if they are tall, their leaves can be easily cut and utilised for feeding. Profuse branching makes it desirable for grazing.

Watershed management involves building of small check dams which leads to an increase in ground water levels. These check dams stop rain water from flowing away and also reduce soil erosion.

This is the correct answer as complete fertiliser is the one that has these three vital elements in it.

This is the correct option as the quality of honey is dependent on all these factors together and not on any one factor alone.

This is an incorrect match as vermicompost is prepared by the actions of earthworms and not of blue green algae.

This is the correct answer. In river lift system, water is directly drawn from the rivers for supplementing irrigation in areas close to rivers. 

This is the correct answer as apiculture is the rearing, breeding, care and management of honey bees for obtaining honey, wax and other substances.

Mackerel is a popular marine fish. Thus, this is the correct answer.

Inappropriate moisture is an abiotic factor that causes grain loss during storage.

This is the correct answer because when two species of the same genus are crossed, it is known as interspecific hybridisation.

This is the correct answer because green manure is prepared by mulching and ploughing some plants like sun hemp and guar into the soil. These green plants turn into green manure which helps in enriching soil.

Fertilisers do not contain any kind of organic matter.

This is the correct answer as xanthium (gokhroo) and parthenium (gajar ghas) are examples of weeds.