Biology IX | Improvement in Food Resources | Part 1


Improvement in Food Resources Part 1

Crops Seasons

Various crops require different climatic conditions, temperature and photoperiod, for their growth and completing their life cycle. Cropping activities go on all the year round in India, provided after is available for the crops. In northern India, there are following two distinct season crops :

1. Kharif season crops.

These crops are growing in rainy seasons, i.e., kharif season from the month of June to October. For example, paddy, soyabean, arhar, maize, millet, cotton, urad and moong are kharif season crops.

2. Rabi season crops.

These crops are grown in winter season, i.e., rabi season from November to April. For example, wheat, gram, peas, mustard, linseed, sugarcane are rabi season crops.

There are certain crops which are grown between March and June and are known as zaid crops.

Improvement in Yields

Following three scientific approaches are adopted in India to obtain high yields from our agriculture farms :

1. Crop production management

2. Crops improvement for higher yield through genetic manipulation

3. Crop protection management

1. Crops production Management

India is a large country with a large area under cultivation. Together with forests and fisheries, agriculture is the backbone of Indian economy. Three fourth of the population is engaged in agriculture. India is blessed with an endless growing season which means that crops can be grown throughout the year. This is because of the subtropical climate and lack of frost in most part of country. Besides providing food, agriculture is a source of raw materials for industries.

It is the money or financial conditions that allow farmers to take higher level farming practices and improved agriculture technology. In fact, in the modern agriculture, there is a direct correlation between higher yields and input application. In other words, farmer’s purchasing capacity for inputs decides the cropping system and production practices. These include ‘no cost’ production, ‘low cost’ production and ‘high cost’ production practices.

(i) Nutrient Management

The food required by plant is composed of certain chemical elements, which are known as nutrients. Through plants absorb a large number of elements from its environment only following sixteen (16) of these are found to be essential for the plant nutrition.

1. Carbon

2. Oxygen

3. Hydrogen

4. Nitrogen

5. Phosphorus

6. Potassium

7. Calcium

8. Magnesium

9. Sulphur

10. Iron

11. Manganese

12. Boron

13. Zinc

14. Copper

15. Molybdenum

16. Chlorine

Deficiency of these nutrients affect physiological processes in plants including reproduction, growth and susceptibility to disease. General health of the plants depend on these nutrients.

Classification of Nutrients

On the basis of quantities required, the 13 nutrients needed for plant growth have been grouped into following two classes : macronutrients and micronutrients.

1. Macronutrients.

The essential elements, which are utilized by plants relatively in large quantities, are called major nutrients or macronutrients. Following six essential nutrients form the example of macronutrients :

1. Nitrogen

2. Phosphorus,

3. Potassium

4. Calcium

5. Magnesium

6. Sulphur

Of these six macronutrients only three namely nitrogen, phosphors and potassium (i.e., N,P,K) are required by plants in greater amounts, they are called primary elements or primary nutrients.

2. Micronutrients.

The essential elements which are used by plants in small quantities (or traces) are called minor nutrients or micronutrients. The following seven essential nutrients form the example of micronutrients :

1. Iron

2. Manganese

3. Boron

4. Zinc

5. Copper

6. Molybdenum

7. Chlorine

Micronutrients may be required in small quantities but they are essential for plant growth as are the macronutrients.

(ii) Manures and Fertilizers

The deficiency of plant nutrients and organic matter in the soil is made up by adding manures and fertilizers to are major sources of nutrients of plants, so they are used in crop production.

Manures

Manures are natural fertilizers. They are bulky sources of organic matter which supply nutrients in small quantities but organic matter in large quantities. Manures are prepared by the decomposition of animal excreta and plant waste. Manures include farmyard manure (FYM), compost, green manures, vermicompost, etc.

Advantages of Manures

(i) The manures enrich the soil with nutrients. They replenish the general deficiency of nutrients in the soil.

(ii) The manures add organic matter (called humus) o the soil which restores the soil texture for better retention of water and for aeration of soil.

(iii) The organic matter of manures provide food for the soil organisms (decomposers such as bacteria, fungi, etc) which help in making nutrients available to plants.

Disadvantages of manures

Manures are bulky with low nutrient content. The nutrients of manures are released slowly, not keeping pace with the high and rapid demand of nutrients by improved high yielding hybrid varieties of crops. Being bulky and voluminous, they are inconvenient to handle, store and transport. Moreover, a manure is not nutrient specific and, hence, it is not much useful when a particular nutrient is required in the soil for a particular crop.

Types of Manures

1. Compost.

Compost is prepared from farm and town refuge such as vegetable and animal refuse e.g., excreta of domestic animals such as cattle, goat, sheep, horse, donkey, camel, dogs, cats, etc.), faecal matter of human beings, sewage waste weeds, which both aerobic (organisms, in which respiration takes place in the absence of oxygen) microorganisms decompose the organic matter.

2. Green Manuring.

The practice of green manuring includes growing, mulching by ploughing and mixing of green crops with soil to improve physical structure and soil fertility.