AGRICULTURE

• Silviculture is the art of cultivating forest trees.
• Sericulture is the rearing of silkworms for the production of raw silk.
• Apiculture is the maintenance of honey bee colonies, commonly in hives by humans.
• Olericulture is the science of vegetable growing, dealing with the culture of non-woody/herbaceous plants for food.
• Viticulture is the science, production & study of grapes.
• Pomology is a branch of horticulture which focuses on the cultivation, production, harvest & storage of fruit.
• Floriculture is a discipline of horticulture concerned with the cultivation of flowering & ornamental plants for gardens.
• Arboriculture is the cultivation, management & study of individual trees, shrubs, vines & other perennial woody plants.
• Aeroponics is the process of growing plants in an air or mist environment without the use of soil or an aggregate medium.
• Geoponics in farming practice, refers to growing plants in normal soil.
• Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil.
• Terrestrial plants may be grown with their roots in the mineral nutrient solution only or an inert medium like perlite, gravel, mineral wool, expanded clay or coconut husk.

1. Scope & Importance of Agriculture

• With a 17.2% contribution to the gross domestic product (GDP), agriculture provides livelihood support to about two-thirds of the country’s population.
• Agriculture accounts for about 14.7% of the total export earnings & provides raw materials to a large number of industries.
• The sector employs 56.7% of the country’s workforce & is the single largest private sector occupation.
• The agriculture sector acts as a bulwark in maintaining food security & in the process, national security as well.

Problems of Indian Agriculture

• Fragmentation of landholding
• Low productivity of land
• Existence of small & marginal farmers
• Dependence of seasonal rainfall
• Regional variation
• Weak land reformation
• Increasing disguised unemployment
• Disorder in the marketing of Agricultural products

Revolutions in Agriculture

2. Crop & Classifications

Agronomy is a Greek word derived from ‘Agro’ meaning ‘Field’ & ‘Nomos’ meaning ‘Management’. It is a specialized branch in agriculture dealing with crop production & soil management. Crops refer to plants that are grown on a large scale for food, clothing & other human uses.

Classification Based on Climate

Classification Based on Growing Season

• Kharif/Monsoon/Rainy Crops: The crops grown in monsoon months from June to October-November, require warm, wet weather during major periods of crop growth, and also require short day length for flowering. Example-cotton, rice, jowar, bajra.
• Rabi/Winter/Cold seasons crops: The crops grown in the winter season from October to March month. Crops grow well in cold & dry weather. Require longer day length for flowering. Example: wheat, gram, sunflower etc.
• Summer/Zaid crops: Crops grown in summer months from March to June. Require warm dry weather for major growth period & longer day length for flowering. Example: groundnuts, watermelon, pumpkin, gourds.

Agronomic Classification of Crops

• Cereals: Cereals are cultivated grasses grown for their edible starchy grains. Larger grains used as staple food are cereals. Rice, wheat, maize, barley, oats. The most important cereal in the world is rice, Bread wheat, Macaroni wheat, dwarf wheat, and emmer wheat.
• Millets: They are annual grasses of the group cereals. But they are grown in less area or less important area whose productivity & economics are less. These are staple foods for poor people. In India pearl millet is a staple food in Rajasthan. Based on area of production & productivity & grain size, millets are classified into major & minor millets.

1. Pearl Millet/Bajra
2. Sorghum/jowar
3. Finger Millet/Ragi

Minor Millets

1. Kodo millet
2. Common millet
3. Fox tail millet
4. Little millet
5. Barnyard millet

• Pulses/Grain Legumes: Pulses are a major source of protein in the Indian diet & provide most of the essential amino acids to a certain degree. Economically, pulses are the cheapest source of protein. It is cultivated to enrich the soil, to utilize the residual moisture & to give revenue in a shorter period. Red gram, Black gram, green gram, cowpea, horse gram, Bengal gram, soya bean, dew gram, peas/garden pea, garden beans.
• Oil Seed Crops: These crops are cultivated for the production of oil. Either for edible industrial or medicinal purposes. They contain more fat. Sunflower, groundnuts, sesame/gingelly, castor, coconut, safflower, rapeseed, mustard, linseed/flax, Niger. 45-50% oil content is present in these seeds.

Sugar Crops

Sugar stem

1. Number of by-products like Molasses, bagasse, pressed.
2. Molasses is used for alcohol & yeast formation.
3. Bagasse is for paper making & fuel
4. Pressmud is used for soil amendment
5. Trash-green leaf & dry foliage waste is used as cattle feed.

• Sugar Beet: Tuber is used for the extraction of sugar. Tubers & tops are used as fodder for cattle feed.
• Fibre Crops: Epidermal hair of seed coats is the economic portion. Lint has industrial value. Stalk is of a fuel nature, garment purpose, the seed for cattle feed & oil is edible.
• Starch Crops /Tuber Crops: Potato, sweet potato, cassava /tapioca.
• Cotton: Uppam cotton, karunaganni, American cotton/Cambodium cotton, sea island cotton/Egyptian cotton.
• Stem Fibers: Jute, sun hemp, sisal hemp & mesta.
• Narcotics: Arecanut, tobacco, betelvine.

Forage & Fodder Crops

• Forage Crops: The entire vegetative part is used as green fodder. The stalks & leaves are the major economic portion of hay-making Hay is cut into pieces & mixed with concentrated animal feed & is fed to animals.
• Legumes: Velvet bean, Egyptian clover, Indian Clover, Lucerne, sirato, sublabel, stylo.
• Grasses: Para Grass, Bermuda Grass, Napier Grass, Guinea Grass, Rhode Grass.
• Plantation Crops: Tea-leaf, coffee-seed, rubber-milk exudation, cocoa-seed.
• Spices & Condiments: Products of crop plants are used to flavour taste & sometimes colour the fresh preserved food. Example-ginger, are garlic, chilli, cumin, onion, coriander, cardamom, pepper, turmeric etc. Medicinal plants include cinchona, opium poppy, belladonna, rauwolfia, liquorice etc. Aromatic plants like lemon grass, citronella grass, palmorsa, Japanese mint, peppermint, rose, jasmine, henna etc.

Classification based on life of crops/duration of crops

• Seasonal crops: A crop completes its life cycle in one season. Example: rice, jowar, wheat etc.
• Two seasonal crops: crops complete their life cycle in two seasons. Examples: cotton, turmeric, ginger.
• Annual crops: crops require one full year to complete their life cycle. Example: sugarcane.
• Biennial crops: crops require two years to complete their life cycle. Example: banana, papaya.
• Perennial crops: crops live for several years. Example: fruit crops, mango, guava etc.

Classification based on cultural method/water

Classification based on economic importance

Classification based on No. of cotyledons

Classification based on the length of photoperiod required for floral initiation

Most plants are influenced by the relative length of the day & night, especially for floral initiation, the effect on plants is known as photoperiodism depending on the length of photoperiod required for floral ignition, plants are classified as:

1. Short-day plants: flower initiation takes place when days are short less than ten hours. Examples: rice, jowar, green gram, black gram etc.
2. Long-day plants: Long days are more than ten hours for floral initiation. Example: wheat, barley etc.
3. Day-neutral plants: photoperiod does not have much influence on phase change for these plants. Example: sunflower, cotton etc.

Tillage: Tillage is the mechanical manipulation of soil with tools & implements for obtaining conditions ideal for seed germination, seedling establishment & growth of crops.

Tilth: It is the physical condition of soil obtained out of tillage or it is the result of tillage. The tilth may be a coarse tilth or moderate tilth. Based on the requirement of crops being grown & the soil where we are cultivating.

Types of Tillage:

Tillage operations may be grouped into on-season tillage & off-season tillage:

On-season tillage: Tillage operations that are done for raising crops in the same season or at the onset of the crop season are known as on-season tillage.

There are two types of preparatory tillage. Primary and secondary tillage

Primary tillage: The tillage operation that is done after the harvest of crops to bring the land under cultivation is known as primary tillage.

Secondary tillage: The tillage operations that are performed on the soil after primary tillage to bring to a good soil tilth are known as secondary tillage.

• Dry tillage: Dry tillage is practised for crops that are sown or planted in dry land conditions having sufficient moisture for the germination of seeds. This is suitable for crops like broadcasted paddy, jute, wheat, oilseed crops, pulses, potato & vegetable crops.
• Puddling tillage: It is also known as wet tillage. The tillage operation that is done on land with standing water is called wet /puddling tillage. Puddling creates an impervious layer below the surface to reduce deep percolation losses of water & to provide a soft seedbed for planting rice.

Off-season tillage: Tillage operations done for conditioning the soil suitably for the forth-coming main season crop are called off-season tillage. Off-season tillage may be of different types: Post-harvest tillage, fallow tillage, summer tillage, and winter tillage.

Special purpose tillage: Tillage operations intended to serve special purposes are said to be special-purpose tillage. They are subsoiling, levelling, clean tillage, blind tillage, wet tillage, and zero tillage.

• Sub-soiling: To break the hard pan beneath the plough layer special tillage operations (Chiseling) are performed to reduce compaction. Sub-soiling is essential once in 4-to 5 years when heavy machinery is used for field operations, seeding, harvesting, transporting etc.
• Blind tillage: It refers to tillage done after seeding or planting the crop either at the pre-emergence stage of the crop plants or while they are in the early stages of growth so that crop plants do not get damaged, but extra plants & broad-leaved weeds are uprooted.
• Clean tillage: It refers to working the soil of the entire field in such a way no living plant is left undisturbed. It is practised to control weeds, soil-borne pathogens & pests.
• Zero tillage: In Zero tillage /no-tillage, a new crop is planted in the residues of the previous crop without any prior soil tillage or seedbed preparation & it is possible when all the weeds are controlled by the use of herbicides.

3. Cropping

Several crops cultivated in a piece of land per annum are cropping intensity. In Tamil Nadu, Punjab the cropping intensity is more than 100%, around 14-0-150%. In Rajasthan, the cropping intensity is less. The yearly sequence & spatial arrangement of crops & fallow in a given area is called the cropping pattern.

• Cropping system: The cropping pattern used on a farm & its interactions with farm resources, other farm enterprises & available technology determine their makeup.
• Multiple Cropping: Growing more than two crops in a piece of land in a year in orderly succession. It is also called intensive cropping. It is used to intensify the production. It is possible only when assured resources are available.
• Double cropping: Growing two crops a year in sequence. Example: rice, pulses.
• Triple cropping: Growing three crops a year in sequence.
• Quadruple cropping: Growing four crops in a year in sequence.
• Monoculture: Repetitive growing of the same sole crop on the same land.
• Mono cropping: Continuous production of one & the same crop year after year or season after season is called mono-cropping.
• Sole Cropping: One crop variety grown alone in a pure stand at normal density.
• Sequential cropping: Growing of two or more crops in sequence on the same field in a year. The succeeding crop is planted after the preceding crop is harvested. The crop intensification is done in the time dimension. Example-rice-rice-cotton. Relay cropping grows the succeeding crop when the previous crop attends its maturity stage or sowing of the next crop immediately before the harvest of the standing crops. Example: paddy-Lucerne, rice-cauliflower-onion-summer gourds.
• Ratoon cropping: Raising a crop with regrowth coming out of roots or stocks of the harvested crop is known as ratoon cropping. Example: sugarcane-8 ratoons in Cuba Banana- one plant crop followed by two ratoon crops normally Sorghum & Lucerne fodder- many ratoons first cutting 70 days & for every 35-40 days. Pineapple crop is extensively rationed.
• Intercropping: Growing two or more crops simultaneously with distinct row arrangements on the same field at the same time.
• Base crop: A primary crop which is planted/sown at its optimum sole crop population in an intercropping situation.
• Intercrop: This is a second crop planted in between rows of base crops to obtain extra yields with intercrop without compromising the main crop yields. Examples: Maize + cowpea,  Sorghum + Red gram

Types of intercropping: Strip intercropping, parallel intercropping, synergistic cropping- additive series, replacement series, multi-storey cropping, relay intercropping, alley cropping.

• Strip intercropping: Growing of two or more crops simultaneously on strips wide enough to permit independent cultivation but narrow enough for the crops to interact with each other. Example: 6 rows of groundnut & 4 rows of red gram in strips.
• Parallel cropping: Growing two crops simultaneously which have different growth habits & no competition among themselves. Example: black gram with maize, soybean with cotton.
• Synergistic cropping: Yields of both crops are higher than those of their pure crops on a unit area basis. Example: potato + sugarcane.
• Multi-storey cropping: Cultivation of more than two crops of different heights simultaneously on a piece of land in any certain period. Example: pepper+ coconut+ pineapple+ cocoa
• Relay intercropping: In a long-duration base crop, growing two sets of intercrops one after another is called relay intercropping. Example: red gram base crop 180 days. Groundnut/onion/coriander-1 set of intercrops.
• Alley cropping: Alley cropping is a system in which food crops are grown in alleys formed by hedgerows of trees or shrubs. The essential feature of the system is that hedge rows are cut back at planting & kept pruned during cropping to prevent shading & to reduce competition with food crops. Example: sub-label raised at 6 meters row spacing. The space between two rows is called Alleys. The intercrops are raised in the alley space. Cotton, sorghum, and black gram are common examples.

Mixed cropping: Growing two or more crops simultaneously intermingled without row arrangement is known as mixed cropping. It is a common practice in most dryland tracts in India. Seeds of different crops are mixed certain proportion & are sown. The objective is to meet the family requirement of cereals, pulses, and vegetables in subsistence farming. Examples include sorghum, bajra, and cowpea are mixed & broadcasted in rainfed conditions to avoid complete crop failures & ascertain the minimum yields.

Intercropping & Mixed cropping:

4. Farming systems

• Wetland farming: Soils flooded or irrigated through lakes, ponds or canals & land is always in a submerged condition known as a wetland. Wetland farming is the practice of growing crops in soils flooded through the natural flow of water for most of the year.
• Irrigated dry land farming/Garden land: Garden land soils irrigated with groundwater sources. Garden land farming: Growing crops with supplemental irrigation by lifting water from underground sources.
• Dryland farming: Dryland soils purely depend on rainfall for moisture. Dryland farming is the practice of crop production entirely depending upon rainfall & the moisture conserved in the soil. This is practised in areas where annual rainfall is less than 750mm. the crops may face moisture stress frequently due to erratic distribution or failure of monsoon.
• Rainfed farming: Crop production in areas where rainfall is more than 750mm. Here moisture stress will be minimal. Soil conservation is given more importance.
• Mixed farming: Mixed farming is defined as a system of farming on a particular farm which includes crop production, raising livestock, poultry, fisheries, beekeeping etc. to sustain & satisfy as many needs of the farmer as possible. Subsistence is an important objective of mixed farming. Higher profitability without altering ecological balance is important in the farming system.
• Specialized farming: The farm in which 50% or more income of total crop production is derived from a single crop is called specialized farming.
• Diversified farming: Diversified farming has several production enterprises or sources of income but no source of income equals as much as 50% of the total income. It is also known as general farming.

• Leguminous crops should be grown before non-leguminous crops because legumes fix atmospheric Nitrogen into the soil & add organic matter to the soil.
• More exhaustive crops should be followed by less exhaustive crops because crops like potato, sugarcane, maize etc need more inputs like better tillage, more fertilizers, greater number of irrigation etc.
• Crops with tap roots should be followed by those which have fibrous root systems. This facilitates proper & uniform use of nutrients from the soil.
• Selection of crops should be based on need or demand. Crops of the same family should not be grown in succession because they act as alternate hosts for insect pests & diseases. The crop selected should suit the soil & climatic conditions.

6. Sustainable Agriculture

• It is a form of agriculture aimed at meeting the needs of the present generation without endangering the resource base of the future generations.
• It is considered a system of cultivation with the use of manure, crop rotation & minimal tillage with minimum dependence on synthetic fertilizers, pesticides & antibiotics.
• It is a balanced management system of renewable resources including soil, wildlife, crops, forests, fish, livestock, plant genetic resources & ecosystems without degradation & to provide food, and livelihood for current & future generations maintaining or improving productivity & ecosystem services of these resources.
• Sustainable agriculture has to prevent land degradation & soil erosion. It has to replenish nutrients & control weeds, pests & diseases through biological & cultural methods.
• The degradation of natural resources is the main issue threatening the sustainable development of agriculture.