Assam ASSEB Higher Secondary Skill Subject Agriculture cheat sheet

Cropping intensity (%) = (sum of area sown in all seasons ÷ net sown area) × 100; multiple cropping index above 100 indicates more than one crop per year on the same land.

Crop seasons in Assam: kharif (sowing with monsoon, June–July), rabi (October–November sowing), and pre-kharif/ahu rice sown March–April; sali rice is the main kharif paddy, boro is winter paddy.

Seed rate rules of thumb: direct-seeded rice 60–80 kg/ha, transplanted rice 40–60 kg/ha, wheat 100 kg/ha, maize 20–25 kg/ha, jute 5–7 kg/ha, rapeseed-mustard 5 kg/ha.

Yield (kg/ha) = grain yield from a plot (kg) × 10,000 ÷ plot area (m²); convert t/ha to q/ha by multiplying by 10.

Land equivalent ratio (LER) = sum of (intercrop yield ÷ sole-crop yield) of components; LER > 1 means the intercrop is more efficient in land use than sole cropping.

Rice needs puddling and 5–7 cm standing water; maize, wheat and pulses are upland crops sensitive to waterlogging, so drainage is essential on Assam's heavy alluvial soils.

Critical crop stages for irrigation: crown root initiation in wheat, panicle initiation and flowering in rice, tasselling and silking in maize, flowering and pod filling in pulses and oilseeds.

Jute (Corchorus olitorius and C. capsularis) is a bast fibre; retting in slow-moving water separates fibre from the stem, and early sowing with the pre-monsoon showers gives taller, finer fibre.

Soil texture triangle classes are set by the percentages of sand, silt and clay; loam is roughly balanced, and clay soils hold more water and nutrients but drain slowly.

Bulk density = oven-dry soil mass ÷ total volume (g/cm³); particle density is about 2.65 g/cm³, so porosity (%) = (1 − bulk density ÷ 2.65) × 100.

Soil pH affects nutrient availability: most nutrients are most available at pH 6.0–7.0; below pH 5.5 aluminium toxicity and phosphorus fixation increase, typical of Assam's acid soils.

Lime requirement rises with soil acidity and target pH; liming acid soils raises pH, reduces Al and Mn toxicity, and improves availability of P, Mo and Ca.

Essential macronutrients: N, P, K, Ca, Mg, S; micronutrients: Fe, Mn, Zn, Cu, B, Mo, Cl, Ni. Liebig's law of the minimum states that the scarcest nutrient limits yield.

N is lost by volatilisation of ammonia from surface-applied urea, by leaching as nitrate, and by denitrification in waterlogged soil; placement and split application reduce losses.

Organic matter improves water-holding capacity, cation exchange capacity and structure; the C:N ratio near 10:1 favours mineralisation, while wide ratios (e.g. straw) cause temporary N immobilisation.

Fertiliser grade N-P₂O₅-K₂O: urea is 46-0-0, single superphosphate 0-16-0 plus sulphur and calcium, muriate of potash 0-0-60, and DAP 18-46-0.

Economic threshold level (ETL) is the pest density at which control measures are justified to prevent the population from reaching the economic injury level; act at ETL, not at first sighting.

Insecticide groups act on different targets: organophosphates and carbamates inhibit acetylcholinesterase; pyrethroids act on sodium channels; neonicotinoids act on nicotinic acetylcholine receptors; Bt toxins bind midgut receptors.

Rice pests: yellow stem borer (dead heart in vegetative stage, white ear at heading), brown planthopper (hopper burn), and gall midge; rice diseases: bacterial leaf blight, blast and sheath blight.

Tea pests of Assam: tea mosquito bug (Helopeltis), red spider mite, looper caterpillar and thrips; integrated management combines pruning, shade regulation and need-based acaricides.

Koch's postulates prove a pathogen causes a disease: the organism is found in diseased tissue, isolated in pure culture, inoculated into a healthy host to reproduce symptoms, and re-isolated.

Disease triangle: disease results from the interaction of a susceptible host, a virulent pathogen and a favourable environment; removing any side prevents epidemic development.

Cultural control examples: crop rotation breaks soil-borne pathogen cycles, resistant varieties, clean seed, destruction of alternate hosts and stubble, and balanced fertiliser to avoid lush susceptible growth.

Pesticide label rules: observe pre-harvest interval, use the recommended dose, wear protective clothing, and never mix formulations unless the label permits; rotate modes of action to delay resistance.

Olericulture is vegetable cultivation, pomology is fruit cultivation, and floriculture is flower cultivation; horticulture as a whole deals with garden crops grown intensively.

Vegetable nursery: raised beds of 10–15 cm height with fine soil, sowing in lines, transplanting when seedlings have 4–6 true leaves; hardening before transplanting improves survival.

Kitchen garden planning uses short-duration, high-yield vegetables in succession; cole crops (cabbage, cauliflower), solanaceous crops (tomato, brinjal, chilli) and cucurbits are common groups.

Fruit crops of Assam: banana, papaya, pineapple, citrus (Khasi mandarin), guava, litchi and mango; vegetative propagation by suckers (banana, pineapple), cuttings (guava) and grafting (citrus, mango).

Pruning and training shape fruit trees and balance vegetative growth with fruiting; bearing habit is terminal (mango), lateral (guava) or on spurs (apple), which determines where to cut.

Floriculture crops include marigold, chrysanthemum, rose, gladiolus and tuberose; marigold is a short-duration annual propagated by seed, chrysanthemum by suckers or cuttings.

Post-harvest handling: sort and grade, pre-cool, avoid bruising, and store at recommended temperature and humidity; ethylene accelerates ripening, so do not store ethylene-sensitive produce with ripening fruit.

Orchard layout systems: square, rectangular, quincunx (filler trees in the centre of squares), hexagonal and contour planting on slopes; plant density = 10,000 ÷ (row spacing × plant spacing in metres).

Ruminant digestion: rumen microbes ferment cellulose to volatile fatty acids; microbial protein supplies amino acids; rumination and saliva buffer rumen pH near 6.5–7.0.

Cattle breeding terms: heat cycle about 21 days, gestation about 280–285 days in cattle and about 150 days in goats; oestrus detection and timely insemination determine conception.

Poultry incubation: chicken eggs hatch in 21 days at about 37.5–37.8 °C with 55–60% relative humidity, turning eggs several times daily; duck eggs take 28 days.

Poultry feeding: chicks need starter mash with higher protein (about 20–22% crude protein), growers and layers need lower protein with adequate calcium for shell formation.

Vaccination schedule basics: Marek's disease at day-old, Newcastle disease (Ranikhet) and infectious bursal disease in early weeks; keep cold chain intact.

Signs of health and disease: healthy animals are alert with normal appetite, temperature and droppings; isolation and veterinary advice are needed for sudden mortality or respiratory signs.

Milk composition and hygiene: clean milking, cooling, and testing; adulteration checks include specific gravity and fat tests, and somatic cell counts indicate udder health.

Feed conversion ratio (FCR) = feed consumed ÷ weight gain or output; lower FCR means more efficient conversion, a key measure in poultry and piggery.

Tractor power take-off (PTO) drives implements; draft is the horizontal pull force, and drawbar power = draft × forward speed.

Implement calibration: seed drill rate is checked by collecting seed from a few tubes over a measured distance and comparing with the recommended kg/ha.

Irrigation water measurement: 1 hectare-millimetre = 10 m³; 1 litre per second for one hour delivers 3.6 m³.

Soil moisture tension: field capacity is about −0.03 MPa and permanent wilting point about −1.5 MPa; available water is the difference between them.

Irrigation scheduling: apply water when the allowable depletion of available water is reached; critical stages need assured supply and deficit irrigation saves water at less sensitive stages.

Drip and sprinkler systems: drip places water at the root zone with high efficiency, sprinkler suits close-growing crops; both need filtration and pressure regulation.

Farm structures and machinery safety: guards on PTO shafts and belts, and proper storage and maintenance extend machinery life and prevent accidents.

Drainage removes excess water from waterlogged fields; surface drains and raised beds are used where rainfall is high, as in Assam's flood-prone areas.

Gross income = yield × price; net income = gross income − total cost; farm profit is maximised where marginal revenue equals marginal cost.

Cost concepts: fixed costs do not vary with output (land rent, machinery depreciation), variable costs do (seed, fertiliser, labour); total cost is their sum.

Benefit-cost ratio = total benefits ÷ total costs; a ratio above 1 indicates a profitable investment, and the internal rate of return is the discount rate at which net present value is zero.

Farm records include physical records (area, yield, livestock numbers) and financial records (receipts, payments); they support planning, credit applications and tax compliance.

Marketing functions: assembling, grading, storage, transport, processing, packaging and financing; each adds form, place or time utility.

Marketing channels move produce from producer to consumer; shorter channels reduce margins taken by intermediaries but may lose scale and storage benefits.

Price behaviour: seasonal price falls at harvest and rises later create storage arbitrage opportunities when storage cost is below the expected price rise.

Cooperative and contract farming: cooperatives pool members' produce and inputs, while contracts fix price and quality in advance, reducing market risk for farmers.

Extension teaching methods: individual (farm visits, office calls), group (demonstrations, meetings) and mass (radio, posters, leaflets); choose the method by audience size and objective.

Adoption process stages: awareness, interest, evaluation, trial and adoption; innovators adopt first and laggards last, so extension targets the early majority.

Demonstration types: method demonstration shows how to do a practice; result demonstration shows the outcome of a practice compared with local practice.

Rural development programmes aim at income, employment, infrastructure and social welfare; self-help groups and microfinance link savings to enterprise credit.

Entrepreneurship traits: opportunity recognition, risk-bearing, resource mobilisation and innovation; a business plan covers product, market, cost, and expected returns.

Value addition through processing, grading, packaging and branding raises the share of the consumer rupee retained by the producer.

Communication elements: sender, message, channel, receiver and feedback; noise distorts the message, and feedback confirms understanding.

Extension evaluation measures knowledge change, adoption and yield or income change; baseline data are needed before the programme starts.

Sustainable agriculture balances productivity, profitability, environmental quality and social equity; it aims to conserve soil, water and biodiversity for future use.

Organic farming excludes synthetic fertilisers and pesticides; it relies on compost, green manure, biofertilisers, crop rotation and biological pest control, and requires certification and a conversion period.

Biofertilisers: Rhizobium fixes nitrogen in legume nodules, Azotobacter and Azospirillum are free-living or associative N fixers, and phosphate-solubilising bacteria release bound soil phosphorus.

Green manure crops such as dhaincha (Sesbania) and sunhemp are grown and ploughed in to add organic matter and nitrogen; legume green manures add both.

Composting: the C:N ratio near 25–30:1, moisture around 50–60% and regular turning favour aerobic decomposition; vermicompost uses earthworms to produce nutrient-rich castings.

Integrated nutrient management combines organic manure, chemical fertiliser and biofertiliser to sustain yield and soil health; integrated pest management combines cultural, biological, mechanical and chemical methods.

Environmental hazards of agriculture: nitrate leaching, pesticide residue, soil erosion, salinisation from over-irrigation, and greenhouse gas emissions from flooded rice and ruminants.

Soil conservation measures: contour bunding, terracing, strip cropping, cover crops and mulching reduce runoff and erosion on sloping land.

Soil sampling: collect from several points in a zigzag pattern, mix to a composite sample, air-dry in shade, and label with field, depth and date before analysis.

Seed germination test: count normal seedlings from a known number of seeds, and germination (%) = (germinated seeds ÷ total seeds sown) × 100; test viability with a tetrazolium or float test.

Pest and disease scouting: sample plants at random from several spots, count infested plants or insects per unit, and compare with the economic threshold before spraying.

Pesticide dilution: quantity of formulation = (desired concentration × volume of spray) ÷ concentration of formulation; calibrate the sprayer for uniform output.

Plant propagation practice: raise nursery beds, use clean seed, water lightly, prick out seedlings, and harden before transplanting; cuttings need nodes and adequate humidity.

Field measurement: area of a rectangular plot = length × width; pace or tape measurements are converted to hectares (10,000 m² = 1 ha).

Record keeping in practicals: note date, treatment, replication, observation and result; a control plot is essential for valid comparison.

Safety in the laboratory and field: label chemicals, wear gloves and masks, avoid eating in the field, and dispose of pesticide containers safely.