BGCSE Agriculture 0599 cheat sheet

Germination percentage = (number of seeds germinated ÷ number of seeds sown) × 100; a seed lot below about 80% is normally rejected for field sowing.

Seed rate (kg/ha) = (target plant population per ha × 1000-grain weight in g) ÷ (germination % × establishment % × 1000).

Crop rotation rule: alternate cereals with legumes and never grow the same family on the same plot in consecutive seasons to break pest and disease cycles.

Legumes fix nitrogen through Rhizobium nodules; a good legume stand can leave roughly 40-80 kg N/ha for the following crop.

Photosynthesis equation: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2; respiration reverses this to release energy for growth.

Transplanting reduces the field period and seedling losses but seedlings must be hardened off and watered in to avoid transplant shock.

Weed control decision: hand weeding suits small plots, but the critical weed-free period for most row crops is the first 4-6 weeks after emergence.

Pruning and training improve light interception and airflow, reducing fungal disease pressure and improving fruit quality.

Gestation periods: cattle about 283 days, sheep and goats about 150 days, pigs about 114 days, rabbits about 31 days.

Poultry incubation is 21 days for chickens and 28 days for ducks; incubation temperature is about 37.5 °C with regular turning.

Ruminants digest fibre via microbial fermentation in the rumen; non-ruminants such as pigs and poultry need more concentrated feed.

Feed conversion ratio = feed consumed (kg) ÷ liveweight gain (kg); a lower ratio means more efficient conversion.

Colostrum must be fed within the first hours after birth because it supplies antibodies and the gut absorbs them only briefly.

Castration, dehorning and ear tagging are routine husbandry operations; hygiene and pain control reduce infection and stress.

Balanced ration rule: energy, protein, minerals, vitamins and water must all be supplied; water is the most limiting nutrient.

Signs of heat in cattle include standing to be mounted, clear mucus discharge and restlessness; heat lasts roughly 12-18 hours.

Soil texture triangle classifies soil by percentages of sand, silt and clay; loam is a balanced mixture with good workability.

Soil pH affects nutrient availability: most crops grow best between pH 5.5 and 7.0, and lime raises pH while sulfur lowers it.

Cation exchange capacity (CEC) is the soil's ability to hold exchangeable cations; clay and organic matter raise CEC.

Water-holding capacity rises with clay and organic matter content, but heavy clay drains slowly and is prone to waterlogging.

Contour ploughing, terracing and strip cropping reduce soil erosion on slopes by slowing runoff and trapping sediment.

Soil structure is improved by adding organic matter and by avoiding tillage and traffic when soil is wet.

NPK fertiliser grades state the percentage of nitrogen, phosphorus (as P2O5) and potassium (as K2O) in that order.

Soil sampling must be representative: take several cores across the field, mix them, and test the composite before applying lime or fertiliser.

Ploughs invert and break soil; harrows level and pulverise it; cultivators loosen it - match the implement to the tillage objective.

Three-point linkage categories match tractor and implement; check that the implement is compatible before hitching.

PTO (power take-off) speed is typically 540 rpm; the tractor engine speed must be set to achieve the rated PTO speed.

Field capacity (ha/h) = (implement working width in m × forward speed in km/h) ÷ 10, before allowing for turning and filling time.

Machinery maintenance rule: check oil, coolant, tyres and belts before use, and grease moving parts at the intervals in the manual.

Store tools with sharp edges covered, blades downward, and handles sound; damaged handles must be replaced, not taped.

Animal housing needs ventilation, dry bedding and drainage; stocking density above recommended levels increases disease and stress.

Sheds and stores should be sited on well-drained ground with good access for vehicles and away from watercourses.

Gross margin = gross output (sales value) − variable costs; it excludes fixed costs and is used to compare enterprises.

Profit = total revenue − total costs (variable plus fixed); a positive gross margin does not guarantee an overall profit.

Break-even yield = total fixed costs ÷ (price per unit − variable cost per unit).

Farm records fall into physical, financial and supplementary types; accurate records underpin planning, credit applications and tax.

Depreciation (straight line) = (purchase cost − salvage value) ÷ useful life in years.

Labour productivity = output ÷ labour input (hours or workers); it measures efficiency of the workforce.

Marketing margin = consumer price − farm-gate price; it covers transport, processing, storage and trader profit.

Budgeting compares planned costs and returns before committing resources; partial budgets assess a single change.

Plant nutrients are macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Zn, Cu, B, Mo, Cl); both groups are essential.

Nitrogen promotes leaf and stem growth; phosphorus supports roots and flowering; potassium strengthens stems and improves fruit quality.

Nutrient deficiency symptoms: yellowing older leaves suggests nitrogen shortage; purple leaves suggest phosphorus shortage.

Plant growth stages are germination, vegetative growth, flowering, pollination, fertilisation, seed and fruit formation, and maturity.

Pests include insects, mites, nematodes and molluscs; diseases are caused by fungi, bacteria, viruses and nematodes.

Integrated pest management combines resistant varieties, cultural control, biological control and targeted chemicals as a last resort.

Animal digestion in ruminants involves the rumen, reticulum, omasum and abomasum; microbial fermentation precedes true digestion.

Genetics and breeding: selection of superior parents and crossbreeding exploit heterosis to improve yield and hardiness.

Pesticide handling rule: wear gloves, boots, coveralls and eye protection; never eat, drink or smoke during application.

Observe the pre-harvest interval on the pesticide label to keep residues below permitted limits.

Store pesticides in a locked, labelled cabinet away from food, feed and children; keep the safety data sheet available.

Tractor roll-over protection and seat belts reduce fatalities; never carry passengers unless a safe seat is fitted.

Noise above about 85 dB requires hearing protection; prolonged exposure causes permanent hearing loss.

Zoonoses such as brucellosis, leptospirosis and ringworm pass from animals to people; hygiene and protective clothing reduce risk.

First aid for chemical on skin: remove contaminated clothing and wash with plenty of water; seek medical advice and show the label.

Livestock handling facilities should have non-slip floors, secure gates and escape routes to prevent crushing injuries.

Sustainable systems balance economic viability, environmental protection and social equity over the long term.

Crop rotation, cover crops and mulching build soil organic matter and reduce erosion and nutrient leaching.

Integrated nutrient management combines organic sources such as manure and compost with mineral fertiliser to match crop demand.

Water conservation measures include drip irrigation, rainwater harvesting, mulching and contour ditches.

Agroforestry integrates trees with crops or livestock, improving shade, wind protection, soil fertility and biodiversity.

Overgrazing removes vegetation cover, causing compaction, erosion and reduced pasture regrowth; stocking rate must match carrying capacity.

Buffer strips along watercourses filter sediment and nutrients, protecting streams from agricultural runoff.

Biodiversity on farms is supported by hedgerows, field margins, ponds and reduced pesticide use, which protect pollinators and predators.