Using manure and fertilizers as an agriculture practice is important as continuous growth of crops makes the soil poorer in certain nutrients. These both are added to the soil in the form of nutrients for the healthy growth of plants. Manure replenishes the soil with nutrients and also improves water retaining capacity whereas fertilizers make soil rich in a particular nutrient. They also help farmers to get better yield of crops.

Water is essential for plants. It helps in germination of seeds because seeds cannot germinate under dry conditions. Nutrients dissolves in water get transported to each part of the plant. It protects the crop from frost and hot air currents. Water is important for proper growth and development of flowers, fruits and seeds of plants. Along with water, minerals and fertilizers are also absorbed. Plants contain nearly 90% water. The time and frequency of irrigation varies from crop to crop, soil to soil and season to season.

The planting of a leguminous crop in a field has the same effect as adding nitrogenous fertiliser in the field. They can fix atmospheric nitrogen themselves by using nitrogen-fixing bacteria in their root nodules. Therefore, nitrogenous fertilisers are not required for growing leguminous plants.

Soil is the source for plants from which they derive their mineral nutrients, essential for their growth. If crops are grown continuously in the same field, for a long period of time, the soil becomes poorer in nutrients. Thus, soil gets deficient in nutrients and the field becomes infertile.

Wheat seeds need low temperature and less humidity to grow. If they are sown in kharif season, (i.e. rainy season), the seeds would get destroyed due to excess of water and would not grow.

Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light. They affect growth of the crop. Some weeds may be poisonous for animals and human beings.

Amaranthus (chaulai) and Chenopodium (bathua) are commonly found weeds in rice and wheat fields.

The process of providing manure to replenish the soil with nutrients is called manuring.

Traditional methods use manpower and animal power, and there is a wastage of water also during irrigation. To overcome these problems modern methods of irrigation are used.

The rabi crops are known as winter crops because they are grown in winter season, e.g. wheat, gram, etc.

The supply of water to crops at different intervals is called irrigation. Various systems of irrigation are:
(i) Traditional methods: The water available in wells, lakes and canals is lifted up by
(a) Moat (Pulley system);
(b) Chain pump
(c) Dhekli and;
(d) Rahat (Lever system)
Pumps are commonly used for lifting water.
(ii) Modern methods:
(a) Sprinkler system: This system is more useful on uneven land. The perpendicular pipes, having rotating nozzles on top, are jointed to the main pipeline at regular intervals. When water flows through main pipes, it gets sprinkled on the crop as if it is raining.
(b) Drip system: In this system water falls drop by drop just at the position of the roots. It is the best technique for watering fruit plants, garden and trees

(a) We will find seedlings in all the glasses.
(b) Glass B shows maximum growth as it contained urea which is a rich source of nitrogen.
(c) Manures and fertilisers are essential for better growth of plants.
(d) Manure is a natural substance obtained by the decomposition of animal and plant residues.
(e) Soil fix up the plant. It also retains water for plant absorption.