Comprehensive theory, key formulas, diagrams, and memory aids for Improvement in Food Resources.
We know that all living organisms need food. Food supplies proteins, carbohydrates, fats, vitamins, and minerals, all of which we require for body development, growth, and health. Both plants and animals are major sources of food for us.
India has a very large population, which is constantly growing. To feed this growing population, we need to increase our production of food. We have had the Green Revolution, which contributed to increased food-grain production, and the White Revolution, which led to better and more efficient use as well as availability of milk. However, these revolutions mean that we are using up our natural resources more intensively.
Therefore, it is necessary to increase our production efficiency for both crops and livestock without degrading our environment.
Cereals (wheat, rice, maize) provide carbohydrates for energy. Pulses (gram, pea) provide protein. Oil seeds (soyabean, groundnut, sesame) provide necessary fats. Vegetables, spices, and fruits provide a range of vitamins and minerals. Different crops require different climatic conditions, temperature, and photoperiods (duration of sunlight) for their growth and completion of their life cycle. * Kharif Crops: Grown in the rainy season (June to October). Examples: Paddy (rice), soyabean, pigeon pea, maize, cotton, green gram. * Rabi Crops: Grown in the winter season (November to April). Examples: Wheat, gram, peas, mustard, linseed.
The major groups of activities for improving crop yields can be classified as: 1. Crop variety improvement. 2. Crop production improvement. 3. Crop protection management.
This approach depends on finding a crop variety that can give a good yield. Varieties can be selected by breeding for various useful characteristics such as disease resistance, response to fertilizers, product quality, and high yields. * Hybridization: Crossing between genetically dissimilar plants. It can be intervarietal (between different varieties), interspecific (between species), or intergeneric (between genera). * Genetic Modification (GM): Introducing a gene that would provide the desired characteristic (e.g., Bt Cotton).
Why improve varieties? * Higher yield: To increase productivity per acre. * Improved quality: Baking quality in wheat, protein quality in pulses. * Biotic and abiotic resistance: Resistance to diseases/insects (biotic) and drought/salinity/heat (abiotic). * Change in maturity duration: Shorter duration allows farmers to grow multiple rounds of crops a year and reduces cost.
In India, farming ranges from small to very large farms. The financial conditions of farmers allow them to take up different farming practices and agricultural technologies.
A. Nutrient Management Just as we need food, plants require nutrients. There are 16 nutrients essential for plants. * Air supplies: Carbon and Oxygen. * Water supplies: Hydrogen and Oxygen. * Soil supplies: 13 nutrients. Six are required in large quantities (macronutrients: Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur). Seven are required in small quantities (micronutrients: Iron, Manganese, Boron, Zinc, Copper, Molybdenum, Chlorine). * Manure: Contains large quantities of organic matter and supplies small quantities of nutrients. It helps in enriching soil with nutrients and increasing water holding capacity. It is prepared by the decomposition of animal excreta and plant waste (Compost/Vermicompost). * Fertilizers: Commercially produced plant nutrients. They supply Nitrogen, Phosphorus, and Potassium (NPK). They ensure good vegetative growth (leaves, branches, and flowers) giving rise to healthy plants. However, continuous use can destroy soil fertility.
B. Irrigation Most agriculture in India is rain-fed. Poor monsoons cause crop failure. Ensuring crops get water at the right stages increases yields. Sources include wells, canals, rivers, and tanks. Newer methods include drip and sprinkler irrigation which save water.
C. Cropping Patterns Different ways of growing crops can be used to give maximum benefit. * Mixed Cropping: Growing two or more crops simultaneously on the same piece of land (e.g., wheat + gram, or wheat + mustard). This reduces risk. * Intercropping: Growing two or more crops simultaneously in a definite pattern (a few rows of one crop alternate with a few rows of another). Ensures maximum utilization of nutrients. * Crop Rotation: Growing different crops on a piece of land in a pre-planned succession. If done properly, two or three crops can be grown in a year with good harvests.
Crops in the field are infested by a large number of weeds, insects, pests, and diseases. * Weeds: Unwanted plants (e.g., Xanthium, Parthenium). They compete for food, space, and light, taking up nutrients and reducing crop growth. They can be removed mechanically or by using chemicals called herbicides. * Insect Pests: They cut the root, stem, and leaf; suck cell sap; or bore into stems and fruits. Controlled using insecticides. * Diseases: Caused by pathogens like bacteria, fungi, and viruses transmitted through soil, water, and air.
Storage of Grains: High losses can occur during storage due to biotic factors (insects, rodents, fungi, mites) and abiotic factors (inappropriate moisture and temperature). Preventive measures include strict cleaning, proper drying (first in sunlight and then in shade), and fumigation.
Animal husbandry is the scientific management of animal livestock. It includes feeding, breeding, and disease control.
Cattle husbandry is done for two purposes: milk and draught labour for agricultural work (tilling, irrigation, carting). * Milch Animals: Milk-producing females. * Draught Animals: Used for farm labour. * To increase milk production, exotic/foreign breeds (e.g., Jersey, Brown Swiss) having long lactation periods are cross-bred with local breeds (e.g., Red Sindhi, Sahiwal) which have excellent resistance to diseases.
Cattle need proper shelter (well-ventilated, roofed sheds) and good animal feed (roughage containing mostly fibre, and concentrates containing high proteins). They must be protected from parasites and infectious diseases via vaccination.
Undertaken to raise domestic fowl for egg production and chicken meat. * Layers: Raised for eggs. * Broilers: Raised for meat. * Cross-breeding between Indian (e.g., Aseel) and foreign (e.g., Leghorn) breeds is focused on developing new varieties with traits like high number/quality of eggs, dwarf broiler parent, and tolerance to high temperatures.
Fish is a cheap source of animal protein. * Marine Fisheries: India's marine fishery resources include 7500 km of coastline. Popular marine fishes: Pomfret, Mackerel, Tuna, Sardines. Yield is increased by locating large schools of fish using satellites and echo-sounders. * Inland Fisheries: Fresh water resources include canals, ponds, reservoirs, and rivers. Composite fish culture is often used, where a combination of 5 or 6 fish species is used in a single fishpond. These species are selected so that they do not compete for food (e.g., Catlas are surface feeders, Rohus feed in the middle, Mrigals are bottom feeders). This increases the fish yield from the pond.
Honey is widely used, making bee-keeping an agricultural enterprise. It requires low investment and provides additional income. Beehives are a source of honey and wax (used in medicinal preparations). * Local varieties: Apis cerana indica (Indian bee), Apis dorsata (rock bee). * An Italian bee variety, Apis mellifera, is commonly used for commercial honey production because of its high honey collection capacity and the fact that they stay in a given beehive for long periods and breed very well.
Meeting the food demands of a growing population requires scientific intervention in agriculture and animal husbandry. For crops, this involves developing high-yielding, resistant varieties, managing nutrients through manure and fertilizers, employing smart cropping patterns, and protecting yields from pests and diseases. For livestock, cattle, poultry, fish, and bees are selectively bred and managed to maximize the production of milk, meat, eggs, and honey. Sustainable practices are emphasized to ensure that increased production does not destroy the environment that sustains it.