Agricultural Science
Table Of Content
- Meaning Of Nutrient Cycles
- Meaning Of Nitrogen Cycles
- Importance Of Nitrogen Cycle
- Meaning Of Carbon Cycle
- Importance Of Carbon Cycle
- Meaning Of Water Cycle
- Importance Of Water To Crops
Nutrient Cycles
Nutrient cycles refer to the circulation of certain nutrients like nitrogen, carbon and water in nature.
1. Nitrogen Cycle
Nitrogen cycle involves the complex process by which nitrogen is naturally added and removed from the soil. It is a sequence of reaction, indicating the various means by which nitrogen is added to and removed from the atmosphere and the soil.
Importance Of Nitrogen Cycle
Nitrogen cycle is nature’s way of regulating the amount of nitrogen in the soil and air.
Nitrogen fixation process involves soil organisms which add reasonable amount of nitrogen to the soil.
Ways By Which Nitrogen Is Added To The Soil In The Nitrogen Cycle
These are the ways by which nitrogen is added to the soil in the Nitrogen cycle:
1. Direct fixation by lightning during rainfall (Electrical discharge).
2. Incorporation into the soil by free living bacteria or non-symbiotic bacteria.
3. Nitrogen fixing bacteria in the root modules.
4. Decomposition of organic matter.
5. Application of nitrogenous fertilizers.
6. Ammonification.
7. Nitrification.
2. Carbon Cycle
Carbon cycle involves the series of processes which contribute to the circulation of carbon in nature.
Importance Of Carbon Cycle
1. Plants use carbon dioxide obtained from the air to manufacture their food during photosynthesis.
2. It provides carbon which is the major building block for all organic matters.
3. It helps to purify the atmosphere and also to maintain atmospheric level of carbon dioxide.
5. Organic matter which is made from carbon helps to replenish soil nutrients.
3. Water Cycle
Water cycle is defined as the continuous movement of water from the atmosphere to the earth and from the earth to the atmosphere.
Importance Of Water To Crops
1. Water provides the medium for absorption of mineral salts.
2. It facilitates the transfer of nutrients to other parts of plants where they are used in various metabolic processes.
3. Water is an essential raw material in the process of photosynthesis.
4. It helps in seed germination.
5. It helps to sustain life.
6. It helps to maintain plant turgor or turgidity.
7. It has a cooling effect on crops.
8. It is a constituent of plant protoplasm.
9. Water is an essential raw material in the process of photosynthesis.
10. Water facilitates enzymatic activities occuring in crop plants.
11. It is used for hydrolizing food substances such as starch, proteins, fats and oil for easy transmission to other parts of plants.