Mustard is a rabi crop. It is the correct answer as it does not depend upon monsoon rain for growth.

Rhizobium is present in the root nodules of leguminous plants. These bacteria convert atmospheric nitrogen into simpler nitrogen compounds that can be easily absorbed by plants. Hence, it is the correct answer.

Seeds are treated with fungicides to avoid seed-borne diseases. So, this is the correct answer.

Clayey soil needs less frequent irrigation due to its good water holding capacity. So, it is the correct answer.

Weedicides are used to kill weeds.

This is the modern method for irrigation as in this system, holes in pipes allow water to fall drop by drop just at the position of roots. Water is not wasted at all. 

For hybridisation, one plant is selected as male and the other one as female. The anthers of female plants are removed at the bud stage to prevent self-pollination. This process is called emasculation. Hence, it is the correct option.

Urea is a nitrogenous fertiliser. Hence, it is the correct option.

Correct Answer: Loose soil particles hold less water for longer duration

This is used for removing weeds and for loosening the soil. 

This is the correct option. It a structure, typically cylindrical, in which fodder or forage is kept. 

The breeding, rearing and transplantation of fish by artificial means is called pisciculture.

This is the correct answer. Third step is the replenishment of nutrients in the soil. 

This is the correct option. In this method, land is left uncultivated for one or two seasons. The fallow land regains the nutrients by decomposing of remains of plants and animals by the action of microbes.

This is the correct answer. After ploughing, the ploughed land is levelled and pressed lightly with the help of an iron leveller.

This is the correct answer. Loosening and turning of soil is called tilling or ploughing. This is done by using a plough, which is either drawn by a pair of bulls or driven by a tractor.

Harvesting is the process of gathering a ripe crop from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle or reaper. Hence, this is the correct option.

A chemical or natural substance that is added to soil or land to increase its fertility is called fertiliser. Hence, it is the correct option.

Plant breeding is the art and science of changing the traits of plants in order to produce desired characteristics. So, this is the correct option.