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NCEA L1 Ag & Hort study materials
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NCEA L1 Ag & Hort practice questions

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Question 1Agricultural and Horticultural Science

A grower wants a fast, cheap way to raise soil pH in a paddock before sowing pasture. Which material is the standard choice?

  1. Urea
  2. Superphosphate
  3. Elemental sulphur
  4. Ground limestone (calcium carbonate) Correct answer.

Explanation

Liming materials based on calcium carbonate neutralise soil acidity and raise pH, and are the cheapest bulk option for a paddock. Superphosphate and urea supply nutrients but do not correct acidity, and elemental sulphur acidifies soil rather than raising pH.

Question 2Agricultural and Horticultural Science

Which soil structure type gives the best balance of drainage and water-holding for pasture roots?

  1. Massive clay with no aggregation
  2. Platy structure compacted by stock
  3. Crumb structure with stable aggregates Correct answer.
  4. Single-grain sand

Explanation

Crumb structure consists of small, stable aggregates that create both large pores for drainage and small pores that hold water available to roots. Massive clay, single-grain sand and compacted platy layers each fail on one side of the drainage–retention balance.

Question 3Agricultural and Horticultural Science

A farmer applies nitrogen fertiliser to a paddock and then heavy rain falls. Which process most directly causes nitrogen to be lost from the root zone into groundwater?

  1. Volatilisation of ammonia
  2. Denitrification
  3. Leaching of nitrate Correct answer.
  4. Immobilisation by microbes

Explanation

Nitrate is negatively charged and is not held by soil particles, so it moves readily with drainage water below the root zone. Denitrification and volatilisation lose nitrogen as gas to the atmosphere, and immobilisation keeps nitrogen in the soil in organic form.

Question 4Agricultural and Horticultural Science

Why do many New Zealand farmers rotationally graze dairy cows rather than set-stocking a paddock continuously?

  1. It reduces the need for any fertiliser inputs
  2. It allows pasture to recover leaf area between grazings and improves utilisation Correct answer.
  3. It prevents cows from producing methane
  4. It eliminates the need for fencing and water troughs

Explanation

Rotational grazing gives pasture a spelled recovery period so leaves rebuild carbohydrate reserves and regrow strongly, and it improves pasture utilisation. It does not remove fertiliser needs, stop methane production, or remove infrastructure requirements.

Question 5Agricultural and Horticultural Science

A crop of clover is included in a pasture mix mainly because clover can do which of the following?

  1. Tolerate waterlogging better than any grass
  2. Fix atmospheric nitrogen in root nodules Correct answer.
  3. Repel grass grub adults
  4. Release phosphorus from soil minerals

Explanation

Clovers are legumes that form nodules with Rhizobium bacteria and fix atmospheric nitrogen, which then becomes available to companion grasses. They do not release phosphorus from minerals, repel grass grub, or tolerate waterlogging better than all grasses.

Question 6Agricultural and Horticultural Science

Which set of conditions best describes the environment needed for stored hay to avoid spoilage?

  1. Low moisture and cool, dry conditions Correct answer.
  2. High moisture and warm temperatures
  3. Sealed in plastic while still green
  4. High humidity and no airflow

Explanation

Hay must be dried to a low moisture content before baling so that moulds and bacteria cannot grow, and cool, dry storage keeps it that way. High moisture, humidity or sealing green material encourages heating and spoilage.

Question 7Agricultural and Horticultural Science

A dairy farmer notices cows have a dull coat, poor growth and lameness in young stock. Which trace element deficiency is most consistent with these signs?

  1. Phosphorus
  2. Selenium Correct answer.
  3. Potassium
  4. Cobalt

Explanation

Selenium deficiency in New Zealand is associated with white muscle disease, ill thrift and poor growth in young stock. Cobalt deficiency causes a different wasting syndrome, while phosphorus and potassium are major nutrients with different deficiency signs.

Question 8Agricultural and Horticultural Science

What is the main purpose of applying a drench to newly weaned lambs on a farm?

  1. To improve wool colour
  2. To vaccinate against clostridial disease
  3. To control internal parasites Correct answer.
  4. To supply extra minerals

Explanation

Drenching with an anthelmintic treats internal parasite burdens such as roundworms, which cause poor growth in young stock. Mineral supplementation, vaccination and wool colour are handled by different products and management practices.

Question 9Agricultural and Horticultural Science

A grower wants to reduce the risk of clubroot in a brassica crop. Which practice is most effective?

  1. Irrigating daily to keep soil wet
  2. Applying extra nitrogen just before planting
  3. Lengthening the rotation so brassicas return only after several years Correct answer.
  4. Growing brassicas in the same bed every season

Explanation

Clubroot is caused by a soil-borne organism that survives for many years, so a long rotation away from brassicas is the key control. Continuous brassica cropping, extra nitrogen and daily irrigation do not remove the pathogen and may worsen the problem.

Question 10Agricultural and Horticultural Science

Which pest is a major problem in New Zealand pasture because its larvae feed on roots and reduce pasture production?

  1. Codling moth
  2. Grass grub Correct answer.
  3. Tomato potato psyllid
  4. Varroa mite

Explanation

Grass grub larvae live in the soil and chew pasture roots, causing patches of poor growth and reduced dry matter. Varroa mite affects honey bees, codling moth attacks pip fruit, and tomato potato psyllid affects solanaceous crops.

Question 11Agricultural and Horticultural Science

A market gardener wants to reduce soil erosion on a sloping block. Which practice is most appropriate?

  1. Deep ploughing before every rainfall
  2. Contour planting with a cover crop between rows Correct answer.
  3. Planting rows up and down the slope
  4. Removing all vegetation from the inter-row

Explanation

Contour planting and cover crops slow runoff and hold soil in place, reducing erosion on slopes. Rows running up and down the slope channel water, and bare or repeatedly ploughed soil is far more vulnerable to loss.

Question 12Agricultural and Horticultural Science

Which description best explains why shelterbelts improve the growth of crops on an exposed site?

  1. They block all sunlight from reaching the crop
  2. They increase wind speed at ground level
  3. They raise the water table
  4. They reduce wind speed and therefore reduce evapotranspiration and physical damage Correct answer.

Explanation

Shelterbelts slow wind near the ground, which lowers evaporation and transpiration and reduces mechanical damage to leaves and stems. They do not increase wind speed, raise the water table, or block all sunlight.

Question 13Agricultural and Horticultural Science

A farmer wants to determine the dry matter content of a pasture sample. Which method is appropriate?

  1. Measure the sample volume in a bucket
  2. Estimate dry matter by eye from pasture height
  3. Weigh the sample, dry it in an oven, then reweigh it Correct answer.
  4. Weigh the sample and record the fresh weight only

Explanation

Dry matter is found by weighing fresh herbage, drying it to remove moisture, and weighing again; the loss in weight is the water. Fresh weight alone, visual estimates and volume measurements do not give dry matter content.

Question 14Agricultural and Horticultural Science

Which outcome best shows that a fertiliser trial on pasture has produced a statistically significant result?

  1. The treated paddock had a higher yield in a single unreplicated strip
  2. Replicated plots showed a yield difference unlikely to be due to chance Correct answer.
  3. The farmer believed the treated paddock grew better
  4. The treated paddock looked greener than the control

Explanation

A significant result requires replication and analysis showing that the difference is unlikely to have arisen by chance. Visual impressions, single unreplicated strips and personal belief do not provide that statistical evidence.

Question 15Agricultural and Horticultural Science

Which practice best reduces the risk of nitrate poisoning in stock grazing a crop of lush young ryegrass?

  1. Grazing the crop only when it is long and stemmy
  2. Increasing nitrogen fertiliser before grazing
  3. Putting hungry stock onto the crop at dawn
  4. Feeding a supplement of hay and introducing stock gradually Correct answer.

Explanation

Nitrate poisoning risk is reduced by filling stock with hay and moving them onto the crop gradually so intake is controlled. Lush growth, hungry stock and recent nitrogen application all increase the nitrate load and the risk of poisoning.

Question 16Agricultural and Horticultural Science

A crop is showing interveinal yellowing on older leaves while the veins stay green. Which nutrient deficiency is most likely?

  1. Magnesium Correct answer.
  2. Calcium
  3. Nitrogen
  4. Iron

Explanation

Magnesium is mobile in the plant, so deficiency appears first in older leaves as interveinal chlorosis with green veins. Nitrogen deficiency gives general yellowing, iron deficiency appears on new leaves, and calcium deficiency affects growing points.

Question 17Agricultural and Horticultural Science

Which statement correctly describes the role of soil organic matter in a horticultural soil?

  1. It improves water-holding capacity and nutrient supply Correct answer.
  2. It reduces the soil's ability to hold moisture
  3. It prevents all plant diseases
  4. It has no effect on soil structure

Explanation

Organic matter improves aggregation, water-holding capacity and the slow release of nutrients to plants. It does not leave structure unaffected, reduce moisture retention, or prevent every plant disease.

Question 18Agricultural and Horticultural Science

A grower wants to control aphids on a vegetable crop while protecting beneficial insects. Which approach best fits integrated pest management?

  1. Monitoring aphid numbers and using a selective control only when thresholds are reached Correct answer.
  2. Spraying a broad-spectrum insecticide on a fixed calendar
  3. Removing all beneficial insects from the crop
  4. Ignoring the pest until the crop is harvested

Explanation

Integrated pest management relies on monitoring pest numbers against thresholds and using selective controls so natural enemies are conserved. Calendar spraying of broad-spectrum chemicals, removing beneficials and taking no action all conflict with IPM principles.

Question 19Agricultural and Horticultural Science

Which factor most directly determines the rate at which a pasture species regrows after grazing?

  1. The brand of fertiliser spreader used
  2. The amount of leaf area left after grazing Correct answer.
  3. The number of fence posts in the paddock
  4. The colour of the pasture before grazing

Explanation

Regrowth depends on the leaf area and stored carbohydrate remaining after grazing, because leaves capture light for photosynthesis. Colour, fence posts and spreader brand do not directly determine regrowth rate.

Question 20Agricultural and Horticultural Science

A farmer is deciding whether to use a break crop in a rotation. Which benefit is most directly associated with a break crop?

  1. It removes the need for any fertiliser
  2. It interrupts the build-up of soil-borne pests and diseases Correct answer.
  3. It prevents all weeds from germinating
  4. It guarantees a higher price for the following crop

Explanation

A break crop interrupts the life cycle of pests and diseases that build up under a continuous crop, improving the health of the following crop. It does not guarantee prices, remove fertiliser needs, or prevent all weeds.

Question 21Agricultural and Horticultural Science

Which statement best explains why waterlogging reduces pasture growth?

  1. Waterlogging removes all nutrients from the soil
  2. Roots are deprived of oxygen and cannot respire effectively Correct answer.
  3. Waterlogging raises soil temperature too much
  4. Roots become too dry to absorb water

Explanation

When soil pores are filled with water, oxygen is excluded and roots cannot respire aerobically, which limits nutrient uptake and growth. Waterlogging does not overheat soil, remove all nutrients, or dry roots out.

Question 22Agricultural and Horticultural Science

A vineyard manager wants to reduce frost damage to young shoots. Which method is most commonly used?

  1. Applying nitrogen fertiliser the night before
  2. Compacting the soil around the vines
  3. Overhead sprinklers that apply water during frost Correct answer.
  4. Removing all leaves from the vines

Explanation

Overhead sprinklers protect shoots because the latent heat released when water freezes keeps tissue near 0 degrees Celsius. Nitrogen application, leaf removal and soil compaction do not protect tissue from freezing.

Question 23Agricultural and Horticultural Science

Which statement correctly describes the difference between hay and silage?

  1. Silage is conserved by acid fermentation in a sealed, moist environment Correct answer.
  2. Hay is conserved by acid fermentation in a sealed pit
  3. Hay is made from green material sealed in plastic
  4. Silage is dried to 15 percent moisture before baling

Explanation

Silage is conserved by anaerobic fermentation that produces acid and preserves the moist forage in a sealed environment. Hay is instead dried to a low moisture content before baling.

Question 24Agricultural and Horticultural Science

A farmer wants to assess the economic value of applying nitrogen to a pasture. Which approach is most sound?

  1. Compare the cost of the nitrogen with the value of the extra dry matter it produces Correct answer.
  2. Base the decision on the colour of the pasture after one week
  3. Apply nitrogen whenever the weather is fine
  4. Choose the cheapest nitrogen product regardless of response

Explanation

An economic assessment compares the marginal cost of the fertiliser with the value of the extra pasture dry matter grown. Applying on fine days, choosing the cheapest product, or judging colour alone ignores the response and its value.

Question 25Agricultural and Horticultural Science

Which practice best reduces the risk of soil compaction on a dairy farm during wet periods?

  1. Grazing the paddock at high stocking density when soil is saturated
  2. Cultivating the paddock while it is wet
  3. Keeping stock off paddocks and using a stand-off area Correct answer.
  4. Driving the tractor across the paddock repeatedly

Explanation

Keeping stock off wet paddocks and using a stand-off area prevents treading damage and compaction when soils are most vulnerable. High stock density, repeated tractor traffic and wet cultivation all increase compaction.

Question 26Agricultural and Horticultural Science

Which soil property is most directly improved by adding compost to a sandy horticultural soil?

  1. Water-holding capacity Correct answer.
  2. Drainage rate
  3. Soil pH
  4. Bulk density of stones

Explanation

Compost adds organic matter, which increases the soil's ability to retain moisture in coarse sandy soils. This is a key reason growers incorporate compost before planting.

Question 27Agricultural and Horticultural Science

A grower reads a fertiliser bag labelled 15-10-10. What does the first number represent?

  1. Percentage of potassium
  2. Percentage of phosphorus
  3. Percentage of nitrogen Correct answer.
  4. Total weight of the bag

Explanation

Fertiliser labels follow the N-P-K order, so the first number is the percentage of nitrogen. A 15-10-10 blend contains 15% N, 10% P and 10% K by weight.

Question 28Agricultural and Horticultural Science

Which animal is a ruminant with a four-chambered stomach?

  1. Pig
  2. Chicken
  3. Sheep Correct answer.
  4. Horse

Explanation

Sheep are ruminants, meaning they have a four-chambered stomach (rumen, reticulum, omasum, abomasum) that allows microbial digestion of fibrous pasture. This is why sheep can live mainly on grass.

Question 29Agricultural and Horticultural Science

What is the main reason farmers rotate different crop species on the same land?

  1. To reduce the build-up of soil-borne pests and diseases Correct answer.
  2. To make the paddock look more varied
  3. To increase the number of tractors needed
  4. To lower the cost of seed

Explanation

Rotating crops interrupts the life cycles of soil-borne pathogens and pests that build up when the same species is grown repeatedly. It also helps balance nutrient use across the rotation.

Question 30Agricultural and Horticultural Science

Which term describes a plant that completes its life cycle within one growing season?

  1. Perennial
  2. Biennial
  3. Annual Correct answer.
  4. Deciduous

Explanation

An annual germinates, flowers, sets seed and dies within a single season, such as wheat or peas. This contrasts with plants that persist for multiple years.

Question 31Agricultural and Horticultural Science

A farmer notices a ewe has a swollen, warm udder and abnormal milk. Which condition is most likely?

  1. Bloat
  2. Facial eczema
  3. Mastitis Correct answer.
  4. Footrot

Explanation

Mastitis is an infection of the udder causing swelling, heat and abnormal milk. It is a common production-limiting disease in lactating animals.

Question 32Agricultural and Horticultural Science

Which practice best reduces the risk of a crop lodging (falling over) in a windy site?

  1. Applying extra nitrogen late in the season
  2. Irrigating heavily just before harvest
  3. Sowing at the recommended rate and avoiding excess nitrogen Correct answer.
  4. Sowing as densely as possible

Explanation

Lodging is worsened by excessive nitrogen and overly dense sowing, which produce tall, weak stems. Correct sowing rates and balanced nutrition produce stronger stems.

Question 33Agricultural and Horticultural Science

Which statement best describes the role of a shelterbelt on a pastoral farm?

  1. It replaces the need for fertiliser
  2. It stops all rainfall reaching the paddock
  3. It reduces wind speed and lowers evaporation and physical damage to pasture Correct answer.
  4. It increases wind speed across the paddock

Explanation

Shelterbelts slow wind, reducing evaporation and mechanical damage to plants and animals. This often improves pasture growth and animal comfort on exposed sites.

Question 34Agricultural and Horticultural Science

A grower wants to measure the pH of a soil sample. Which test is most appropriate?

  1. A worm count
  2. A dry matter oven test
  3. A soil pH test using a calibrated meter or colour indicator Correct answer.
  4. A leaf area measurement

Explanation

Soil pH is measured with a calibrated pH meter or a colour indicator test on a soil-water slurry. This directly indicates acidity or alkalinity.

Question 35Agricultural and Horticultural Science

A dairy farmer wants to reduce nitrogen leaching from a paddock. Which practice is most effective?

  1. Increasing stocking rate on the paddock
  2. Spreading nitrogen just before heavy rain
  3. Applying all nitrogen in one large dose in winter
  4. Applying nitrogen in smaller split doses when pasture can use it Correct answer.

Explanation

Splitting nitrogen applications matches supply to plant demand, so less nitrate is left in the soil to leach. Applying when pasture is actively growing further increases uptake.

Question 36Agricultural and Horticultural Science

Which factor most affects the germination rate of pasture seed?

  1. The age of the tractor
  2. Soil temperature and moisture at sowing Correct answer.
  3. The direction the paddock faces
  4. The colour of the seed bag

Explanation

Seed requires adequate warmth and moisture to germinate reliably. Sowing when soil is too cold or dry reduces establishment.

Question 37Agricultural and Horticultural Science

A grower finds white grubs in the soil under a dying pasture. Which group of pests do these most likely belong to?

  1. Slugs feeding on foliage
  2. Root-feeding insect larvae such as grass grub Correct answer.
  3. Aphids feeding on stems
  4. Leaf-chewing caterpillars

Explanation

White grubs in the root zone that cause pasture death are typically root-feeding larvae such as grass grub. They sever roots and reduce the plant's ability to take up water and nutrients.

Question 38Agricultural and Horticultural Science

Which statement best explains why a crop grown in compacted soil grows poorly?

  1. The soil contains too many earthworms
  2. Roots cannot penetrate and water and air movement is restricted Correct answer.
  3. The soil becomes too warm for roots
  4. The soil pH becomes too high

Explanation

Compaction reduces pore space, restricting root growth and the movement of water and air. This limits nutrient uptake and can cause waterlogging.

Question 39Agricultural and Horticultural Science

A farmer wants to increase lambing percentage. Which management factor has the greatest influence?

  1. The colour of the ear tags
  2. The size of the woolshed
  3. Ewe nutrition and condition score at mating Correct answer.
  4. The breed of the ram's horns

Explanation

Ewe nutrition and body condition at mating strongly influence ovulation rate and therefore lambing percentage. Flushing ewes on good pasture before mating is a common management tool.

Question 40Agricultural and Horticultural Science

Which practice best reduces soil erosion on a newly cultivated hillside?

  1. Sowing a cover crop as soon as possible after cultivation Correct answer.
  2. Leaving the soil bare over winter
  3. Ploughing up and down the slope
  4. Removing all vegetation from the paddock

Explanation

A cover crop protects the soil surface from raindrop impact and slows runoff, reducing erosion. Bare soil is highly vulnerable to loss.

Question 41Agricultural and Horticultural Science

A grower wants to check whether a new tomato variety yields more than the current one. Which approach gives the most reliable comparison?

  1. Ask a neighbour which variety they prefer
  2. Grow the new variety only and estimate the yield
  3. Compare the price of the two seed packets
  4. Grow both varieties in replicated plots under the same conditions and compare yields Correct answer.

Explanation

A fair comparison requires replicated plots grown under the same conditions so that differences can be attributed to the variety rather than to soil or weather. Statistical analysis of the results then shows whether the difference is real.

Question 42Agricultural and Horticultural Science

Which statement best explains why legumes such as clover are valuable in pasture?

  1. They require no grazing
  2. They increase soil pH
  3. They fix atmospheric nitrogen through root nodules Correct answer.
  4. They prevent all weed growth

Explanation

Legumes form a symbiotic relationship with rhizobia bacteria in root nodules, converting atmospheric nitrogen into forms plants can use. This adds nitrogen to the pasture system.

Question 43Agricultural and Horticultural Science

A farmer notices stock avoiding a paddock and showing photosensitivity on white areas of skin. Which cause is most likely?

  1. Sporidesmin poisoning from facial eczema Correct answer.
  2. Nitrate poisoning
  3. Grass staggers
  4. Milk fever

Explanation

Facial eczema is caused by the fungus Pithomyces chartarum producing sporidesmin, which damages the liver and causes photosensitisation. Affected animals avoid sun and show skin lesions on unpigmented areas.

Question 44Agricultural and Horticultural Science

Which practice best improves the efficiency of irrigation on a horticultural block?

  1. Applying water until it runs off the surface
  2. Irrigating only after plants wilt severely
  3. Scheduling irrigation based on soil moisture monitoring Correct answer.
  4. Irrigating at the hottest part of the day every day

Explanation

Soil moisture monitoring shows when the crop actually needs water, reducing waste and improving water use efficiency. This avoids over- and under-irrigation.

Question 45Agricultural and Horticultural Science

A grower wants to reduce the risk of a crop disease spreading through a greenhouse. Which practice is most effective?

  1. Crowding plants closer together
  2. Using clean equipment and removing infected plants promptly Correct answer.
  3. Increasing humidity to the maximum
  4. Watering the foliage every evening

Explanation

Sanitation and prompt removal of infected plants reduce the inoculum available to spread disease. Clean tools and hands prevent mechanical transmission between plants.

Question 46Agricultural and Horticultural Science

Which statement best describes the difference between a pasture and a crop in terms of management?

  1. Crops cannot be grown in New Zealand
  2. Pasture is usually grazed repeatedly, while a crop is typically harvested once Correct answer.
  3. Pasture is never fertilised, while crops always are
  4. Pasture does not require water

Explanation

Pasture is a perennial or regenerating sward that is grazed multiple times, whereas most crops are sown, grown and harvested once per cycle. This shapes different management needs.

Question 47Agricultural and Horticultural Science

A farmer wants to calculate the stocking rate for a paddock. Which information is most directly needed?

  1. Pasture dry matter available and daily feed demand per animal Correct answer.
  2. The colour of the animals
  3. The number of gates in the paddock
  4. The age of the farm buildings

Explanation

Stocking rate is based on matching feed supply (dry matter available) to animal demand (dry matter intake per animal). This determines how many animals the paddock can support.

Question 48Agricultural and Horticultural Science

A grower applies lime to a soil with a low pH. Which outcome is expected?

  1. Soil nitrogen is fixed from the atmosphere
  2. Soil becomes completely sterile
  3. Soil pH rises and availability of some nutrients improves Correct answer.
  4. Soil pH falls further

Explanation

Lime is alkaline and neutralises soil acidity, raising pH. This improves the availability of nutrients such as phosphorus and molybdenum and supports better plant growth.

Question 49Agricultural and Horticultural Science

A farmer compares two fertiliser treatments and finds a 12% yield increase with a 20% increase in cost. Which conclusion is most sound?

  1. The result is invalid because costs were measured
  2. The treatment is always worthwhile because yield increased
  3. The treatment should be rejected because costs rose
  4. The economic benefit depends on the value of the extra yield compared with the extra cost Correct answer.

Explanation

A sound economic decision compares the value of the extra yield with the extra cost, not yield alone. If the value of the additional yield exceeds the added cost, the treatment is worthwhile.

Question 50Agricultural and Horticultural Science

Which factor best explains why a pasture species may decline in a sward over several years?

  1. It has been replaced by the farmer deliberately
  2. It is less competitive under the farm's grazing and fertility regime Correct answer.
  3. It has become extinct
  4. It has stopped photosynthesising

Explanation

Species composition shifts toward plants best adapted to the grazing pressure, fertility and climate of the site. Less competitive species decline as more adapted species dominate.