Agricultural and Horticultural Science: Practices, Purposes and Applied Reasoning
Agricultural and Horticultural Science at NCEA Level 1 assesses how well you can explain management practices used to produce plants and animals, and the science ideas behind them. Questions ask you to describe a practice, explain why it is done, and apply that reasoning to a context you may not have seen before - a home garden, a market garden, or a sheep and beef farm.
Plant, animal and soil practices
- Plant management: propagation (seed, cuttings, division, grafting), spacing and planting depth, pruning and training, staking, irrigation, fertiliser application, pest, disease and weed control, harvesting and post-harvest handling.
- Livestock management: feed and water supply, body condition scoring, health treatments (drenching, vaccination, foot trimming), shelter, handling and restraint, identification, and breeding management (mating, gestation, lambing/calving).
- Soil management: texture and structure, organic matter, drainage, pH, and nutrient supply. Practices such as liming, adding compost, crop rotation and minimum tillage all change soil properties.
Linking practice to purpose
Every answer should connect a practice to a need. Pruning removes apical dominance so side shoots grow, improving light penetration and airflow, which reduces disease. Liming raises pH so nutrients such as phosphorus become more available. Drenching controls internal parasites that reduce growth rates.
Worked example
A farmer has 200 ewes. Each ewe needs 1.5 kg of dry matter (DM) per day. Pasture supplies 1.0 kg DM per ewe per day. How much supplementary DM is needed for 10 days? Gap per ewe = 1.5 − 1.0 = 0.5 kg DM/day. For 200 ewes = 0.5 × 200 = 100 kg DM/day. For 10 days = 100 × 10 = 1,000 kg DM = 1 tonne DM. Reasoning: work in DM, not fresh weight, because water content varies. Show the unit at each step.
Traps that cost marks
- Giving a definition when the question says "explain why".
- Mixing dry matter with fresh weight, or dropping units.
- Confusing macro- and micronutrients.
- Describing what was done without naming the scientific reason.