Food
Food is essential for all living organisms to live. We depend on plants and animals for food. The increase in population has created much demand for food. The green revolution contributed to increased food-grain production, and the white revolution contributed to increased availability of milk.
Nutrients in the food
Five main nutrients of our food are carbohydrates, proteins, fats, vitamins and minerals.
Cereals provide carbohydrates, pulses provide proteins, oil seeds provide fats, vegetables, spices and fruits provide vitamins and minerals.
Types of crops
Based on the climatic conditions required for growth, crops are categorized into three types namely, kharif crops, rabi crops and zaid crops.
• Kharif crops are grown in the rainy season which extends from June to October. Kharif crops include paddy, soyabean, maize, cotton, green gram and black gram.
• Rabi crops are grown in the winter season which extends from November to April. Rabi crops include wheat, gram, peas and linseed.
• Zaid crops are grown from March to June. Zaid crops include muskmelon, Watermelon, vegetables of cucurbitaceae.
Increased production of food grains
In India, the production of food grains increased four times from 1960 to 2000. This increase in food production was due to crop variety improvement, crop production improvement and crop protection management.
Crop variety improvement: Crop variety improvement brings in following advantages.
a)Increase in the crop yield
b)Increase in the quality of the crop
c)Development of biotic and abiotic resistant crops.
d)Development of crops with shorter maturity duration.
e)Development of crops with wider adaptability.
f) Introduction of desirable characteristics in crops.
Crop variety improvement can be achieved by the process of selection.
• The criteria for selection are high yield, disease resistance, response to fertilisers, tolerance to climate, etc.
• Hybridisation occurs by a cross between two different varieties, which is known as inter-varietal crossing, or between two different genera, known as inter-generic crossing, or between two different species, known as inter-specific crossing.
• Crop yield can also be increased by introducing desirable genes into the crop plant. Crop yield is related to factors like weather, soil fertility, and availability of water etc. This results in genetically modified crop plants that are able to survive in a drought or flood.
Crop production improvement: It is the protection of crops that are growing or have been harvested. Nutrient management, irrigation and cropping patterns can help improve crop production.
Nutrients required by the plant are calssified into macronutrients and micronutrients. Air supplies carbon and oxygen. Water supplies hydrogen and oxygen. Soil supplies the remaining 13 nutrients to plants. Deficiency of any one of these diseases makes the plant prone to many diseases.
a)Macronutrients are the nutrients required in larger amounts by the plant. Macronutrients include Nitrogen, Phosphorous, Potassium, Calcium, Magnesium and Sulphur.
b)Micronutrients are the nutrients required in smaller amounts by the plant. Micronutrients include Iron, Manganese, Boron, Zinc, Copper, Molybdenum and Chlorine.
Nutrients are replenished into the soil by various methods.
• Manure is produced naturally by the decomposition of animal excreta and plant waste. It contains organic matter, and thus, improves the water-holding capacity in sandy soils, and prevents water logging in clayey soils.
• Compost is prepared by decomposing farm waste, vegetable waste, domestic and sewage waste in pits by the process of composting.
• Vermicompost is prepared by using earthworms to hasten the decomposition of plant and animal waste by the process of vermi-composting.
• Green manure is provided to the plants by ploughing plants rich in nitrogen and phosphorous into the soil before sowing seeds.
• The continuous use of chemical fertilisers kills useful micro-organisms and even destroys soil fertility. Hence, chemical fertilisers are being replaced by bio-fertilisers.
• Biofertilisers are used in organic farming to increase soil fertility. They are prepared by using organisms like blue-green algae. Neem leaves and turmeric are used as biopesticides.
Irrigation is the artificial supply of water to the soil by different methods.
• Irrigation provides water to the plants.
• Irrigation is done by both traditional methods and modern methods.
• Different sources of water are rivers, canals, ponds, lakes, tanks, dams, ground water etc.
• Fields which do not have any water supply from rivers are irrigated by dug wells or tube wells.
• Canals also provide water to crops by obtaining water from reservoirs and rivers.
Cropping pattern helps in the production of more grains in a year. Different cropping patterns are mixed cropping, inter-cropping and crop rotation.
• Mixed cropping is growing two or more crops simultaneously on the same piece of land. e.g. wheat and gram, or groundnut and sunflower.
• Inter-cropping is growing two or more crops simultaneously on the same field with some rows of one crop alternating with some rows of another, like soyabean and maize.
• Crop rotation is growing two or three different crops in a year on a piece of land. e.g. cereals alternating with legumes.
Crop protection management: Nurturing crop plants against damage by weeds, pests and disease is known as crop protection management.
Weeds are the unwanted plants competing with the crop plants for food, space and light, and finally reduce crop growth. Weeds can be removed by spraying herbicides or by removing them mechanically. e.g. Xanthium. Weeds can be controlled by timely sowing of crops, inter-cropping and crop rotation control the growth of weeds. Use of resistant varieties and summer ploughing also reduces the growth of weeds.
Pests attack the plants and reduce their yield. Most of the time insects are the pests which attack plants. They cut the stem and roots, they bore into the stem and fruits. They cut leaves. They suck the cell sap. Pests are controlled by pesticides.
Diseases in plants are caused by pathogens such as bacteria and fungi, and viruses, insects etc. These pathogens are transmitted through soil, water and air. Pathogens can be controlled by spraying herbicides, fungicides, insecticides etc.
Storage losses in crops are due to biotic factors like insects, rodents, fungi, mites and bacteria. Abiotic factors like inappropriate levels of moisture and temperature in the storage area also damage crops.
Grains should be cleaned and properly dried in the sunlight and shade before storage. Fumigation is the process by which grains are exposed to chemical fumes to get rid of pests.
Food
Food is essential for all living organisms to live. We depend on plants and animals for food. The increase in population has created much demand for food. The green revolution contributed to increased food-grain production, and the white revolution contributed to increased availability of milk.
Nutrients in the food
Five main nutrients of our food are carbohydrates, proteins, fats, vitamins and minerals.
Cereals provide carbohydrates, pulses provide proteins, oil seeds provide fats, vegetables, spices and fruits provide vitamins and minerals.
Types of crops
Based on the climatic conditions required for growth, crops are categorized into three types namely, kharif crops, rabi crops and zaid crops.
• Kharif crops are grown in the rainy season which extends from June to October. Kharif crops include paddy, soyabean, maize, cotton, green gram and black gram.
• Rabi crops are grown in the winter season which extends from November to April. Rabi crops include wheat, gram, peas and linseed.
• Zaid crops are grown from March to June. Zaid crops include muskmelon, Watermelon, vegetables of cucurbitaceae.
Increased production of food grains
In India, the production of food grains increased four times from 1960 to 2000. This increase in food production was due to crop variety improvement, crop production improvement and crop protection management.
Crop variety improvement: Crop variety improvement brings in following advantages.
a)Increase in the crop yield
b)Increase in the quality of the crop
c)Development of biotic and abiotic resistant crops.
d)Development of crops with shorter maturity duration.
e)Development of crops with wider adaptability.
f) Introduction of desirable characteristics in crops.
Crop variety improvement can be achieved by the process of selection.
• The criteria for selection are high yield, disease resistance, response to fertilisers, tolerance to climate, etc.
• Hybridisation occurs by a cross between two different varieties, which is known as inter-varietal crossing, or between two different genera, known as inter-generic crossing, or between two different species, known as inter-specific crossing.
• Crop yield can also be increased by introducing desirable genes into the crop plant. Crop yield is related to factors like weather, soil fertility, and availability of water etc. This results in genetically modified crop plants that are able to survive in a drought or flood.
Crop production improvement: It is the protection of crops that are growing or have been harvested. Nutrient management, irrigation and cropping patterns can help improve crop production.
Nutrients required by the plant are calssified into macronutrients and micronutrients. Air supplies carbon and oxygen. Water supplies hydrogen and oxygen. Soil supplies the remaining 13 nutrients to plants. Deficiency of any one of these diseases makes the plant prone to many diseases.
a)Macronutrients are the nutrients required in larger amounts by the plant. Macronutrients include Nitrogen, Phosphorous, Potassium, Calcium, Magnesium and Sulphur.
b)Micronutrients are the nutrients required in smaller amounts by the plant. Micronutrients include Iron, Manganese, Boron, Zinc, Copper, Molybdenum and Chlorine.
Nutrients are replenished into the soil by various methods.
• Manure is produced naturally by the decomposition of animal excreta and plant waste. It contains organic matter, and thus, improves the water-holding capacity in sandy soils, and prevents water logging in clayey soils.
• Compost is prepared by decomposing farm waste, vegetable waste, domestic and sewage waste in pits by the process of composting.
• Vermicompost is prepared by using earthworms to hasten the decomposition of plant and animal waste by the process of vermi-composting.
• Green manure is provided to the plants by ploughing plants rich in nitrogen and phosphorous into the soil before sowing seeds.
• The continuous use of chemical fertilisers kills useful micro-organisms and even destroys soil fertility. Hence, chemical fertilisers are being replaced by bio-fertilisers.
• Biofertilisers are used in organic farming to increase soil fertility. They are prepared by using organisms like blue-green algae. Neem leaves and turmeric are used as biopesticides.
Irrigation is the artificial supply of water to the soil by different methods.
• Irrigation provides water to the plants.
• Irrigation is done by both traditional methods and modern methods.
• Different sources of water are rivers, canals, ponds, lakes, tanks, dams, ground water etc.
• Fields which do not have any water supply from rivers are irrigated by dug wells or tube wells.
• Canals also provide water to crops by obtaining water from reservoirs and rivers.
Cropping pattern helps in the production of more grains in a year. Different cropping patterns are mixed cropping, inter-cropping and crop rotation.
• Mixed cropping is growing two or more crops simultaneously on the same piece of land. e.g. wheat and gram, or groundnut and sunflower.
• Inter-cropping is growing two or more crops simultaneously on the same field with some rows of one crop alternating with some rows of another, like soyabean and maize.
• Crop rotation is growing two or three different crops in a year on a piece of land. e.g. cereals alternating with legumes.
Crop protection management: Nurturing crop plants against damage by weeds, pests and disease is known as crop protection management.
Weeds are the unwanted plants competing with the crop plants for food, space and light, and finally reduce crop growth. Weeds can be removed by spraying herbicides or by removing them mechanically. e.g. Xanthium. Weeds can be controlled by timely sowing of crops, inter-cropping and crop rotation control the growth of weeds. Use of resistant varieties and summer ploughing also reduces the growth of weeds.
Pests attack the plants and reduce their yield. Most of the time insects are the pests which attack plants. They cut the stem and roots, they bore into the stem and fruits. They cut leaves. They suck the cell sap. Pests are controlled by pesticides.
Diseases in plants are caused by pathogens such as bacteria and fungi, and viruses, insects etc. These pathogens are transmitted through soil, water and air. Pathogens can be controlled by spraying herbicides, fungicides, insecticides etc.
Storage losses in crops are due to biotic factors like insects, rodents, fungi, mites and bacteria. Abiotic factors like inappropriate levels of moisture and temperature in the storage area also damage crops.
Grains should be cleaned and properly dried in the sunlight and shade before storage. Fumigation is the process by which grains are exposed to chemical fumes to get rid of pests.