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Botswana JCE Agriculture (Syllabus 16) study materials
Botswana JCE Agriculture (Syllabus 16) study resources

Botswana JCE Agriculture (Syllabus 16) practice questions

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Question 1Introduction to Agriculture and the Agricultural Environment

Which of the following best describes the term 'agriculture'?

  1. The extraction of minerals from underground deposits
  2. The study of wild animals in their natural habitats
  3. The manufacture of machinery in factories
  4. The practice of cultivating crops and rearing animals for human use Correct answer.

Explanation

Agriculture is the deliberate production of plants and animals for food, fibre and other products. It combines crop cultivation with livestock rearing and related activities such as processing and marketing.

Question 2Introduction to Agriculture and the Agricultural Environment

In Botswana, which of the following is the main reason agriculture is important to the national economy?

  1. It provides food, employment and income for most rural households Correct answer.
  2. It generates most of the country's foreign exchange earnings
  3. It supplies raw materials for the mining industry
  4. It supplies fuel for the transport sector

Explanation

Agriculture supports the livelihoods of a large share of Botswana's rural population by providing food, jobs and household income. Although mining earns more foreign exchange, farming remains central to rural welfare and food supply.

Question 3Introduction to Agriculture and the Agricultural Environment

A farmer notices that crops grow poorly on a slope where rainwater runs off quickly. Which environmental factor is most directly limiting plant growth here?

  1. Wind direction
  2. Water availability Correct answer.
  3. Day length
  4. Soil temperature

Explanation

Rapid runoff on a slope reduces the amount of water that infiltrates and remains in the soil for plant roots. Water is therefore the factor most directly limiting growth in this situation.

Question 4Introduction to Agriculture and the Agricultural Environment

Which soil type is generally best suited to crop production because it holds both water and air well?

  1. Gravel
  2. Pure clay
  3. Loam Correct answer.
  4. Pure sand

Explanation

Loam contains a balanced mixture of sand, silt and clay particles, giving good drainage, aeration and water retention. This balance makes it the most suitable soil for most crops.

Question 5Introduction to Agriculture and the Agricultural Environment

Which of the following is a renewable natural resource used in agriculture?

  1. Diamond deposits
  2. Phosphate rock
  3. Solar energy Correct answer.
  4. Petroleum

Explanation

Renewable resources are replenished naturally within a short time, and sunlight is continuously available. Minerals and fossil fuels form over very long periods and are therefore non-renewable.

Question 6Introduction to Agriculture and the Agricultural Environment

A farmer wants to reduce soil erosion on a sloping field. Which practice would be most effective?

  1. Ploughing in the direction of the slope
  2. Burning the vegetation before planting
  3. Planting crops in rows along the contour Correct answer.
  4. Removing all crop residues after harvest

Explanation

Contour planting places rows across the slope, so each row slows runoff and traps soil and water. This reduces the speed of water moving downhill and limits erosion.

Question 7Introduction to Agriculture and the Agricultural Environment

Which of the following describes a symbiotic relationship between leguminous plants and rhizobium bacteria?

  1. The bacteria cause disease in the plant roots
  2. The bacteria break down soil minerals for the plant to store
  3. The plant absorbs bacteria as a food source
  4. The bacteria fix nitrogen while the plant supplies carbohydrates Correct answer.

Explanation

Rhizobium bacteria live in root nodules of legumes and convert atmospheric nitrogen into forms the plant can use. In return, the plant supplies the bacteria with carbohydrates produced through photosynthesis.

Question 8Introduction to Agriculture and the Agricultural Environment

During which part of the day would a farmer expect the highest rate of transpiration from a well-watered crop on a hot, clear day?

  1. Just before sunrise
  2. Late in the evening
  3. Shortly after midnight
  4. Around midday Correct answer.

Explanation

Transpiration is driven by solar energy, warmth and a dry atmosphere, all of which peak near midday. Stomata are open and evaporation demand is highest at that time.

Question 9Introduction to Agriculture and the Agricultural Environment

Which of the following is a climatic factor that most directly determines which crops can be grown in a region?

  1. Rainfall and temperature Correct answer.
  2. Soil parent material
  3. Land tenure system
  4. Farm machinery available

Explanation

Rainfall and temperature set the length of the growing season and the amount of water available to crops. These climatic limits determine which crop species and varieties can succeed in a region.

Question 10Introduction to Agriculture and the Agricultural Environment

A farmer in a semi-arid area wants to conserve moisture for a crop. Which practice is most appropriate?

  1. Flooding the field continuously
  2. Mulching the soil surface with crop residues Correct answer.
  3. Deep ploughing to expose fresh soil
  4. Removing all plant cover between rows

Explanation

Mulch covers the soil and reduces evaporation, keeping moisture in the root zone longer. It also moderates soil temperature and protects the surface from raindrop impact.

Question 11Introduction to Agriculture and the Agricultural Environment

Which of the following best explains why crop rotation with legumes improves the following cereal crop?

  1. The legumes add nitrogen to the soil through fixation Correct answer.
  2. The legumes remove all pests from the field permanently
  3. The legumes lower the soil pH to an ideal level
  4. The legumes increase the clay content of the soil

Explanation

Legumes form nodules with nitrogen-fixing bacteria that enrich the soil with usable nitrogen. The following cereal can then use this nitrogen, reducing the need for purchased fertilizer.

Question 12Introduction to Agriculture and the Agricultural Environment

Which of the following is an abiotic component of an agricultural ecosystem?

  1. Grazing cattle
  2. Soil microorganisms
  3. Earthworms
  4. Soil moisture Correct answer.

Explanation

Abiotic components are the non-living parts of an ecosystem, such as water, air, sunlight, temperature and minerals. Soil moisture is non-living and directly affects plant growth.

Question 13Introduction to Agriculture and the Agricultural Environment

A farmer observes that a field previously used for the same crop for many years now yields poorly despite adequate rainfall. Which explanation is most reasonable?

  1. The crop variety has changed its genetic makeup
  2. The rainfall has become too high for the crop
  3. The field has become too steep for planting
  4. The soil has lost fertility and built up pests and diseases Correct answer.

Explanation

Continuous cropping of the same species depletes specific nutrients and allows pests and diseases to build up in the soil. Rotating crops and restoring fertility would address both problems.

Question 14Introduction to Agriculture and the Agricultural Environment

Which combination of practices best represents sustainable agriculture?

  1. Crop rotation, organic matter recycling and soil conservation Correct answer.
  2. Continuous monocropping with heavy fertilizer use
  3. Irrigating with untreated industrial effluent
  4. Clearing all vegetation to maximise planted area

Explanation

Sustainable agriculture maintains productivity while protecting soil, water and biodiversity for future use. Rotation, recycling organic matter and conserving soil achieve this balance.

Question 15Introduction to Agriculture and the Agricultural Environment

In Botswana's livestock sector, which environmental factor most strongly limits the carrying capacity of communal rangelands?

  1. Presence of pollinating insects
  2. Length of daylight hours
  3. Type of farm machinery used
  4. Availability of drinking water and grazing Correct answer.

Explanation

Rangeland carrying capacity depends mainly on how much forage grows and whether livestock can reach water. In semi-arid Botswana, scarce and erratic rainfall limits both forage and water supply.

Question 16Introduction to Agriculture and the Agricultural Environment

A farmer plans to grow a crop on a field with shallow soil over bedrock on a steep slope. Which conclusion is most justified?

  1. The site is unsuitable only because machinery cannot climb slopes
  2. The site is ideal because shallow soil warms quickly in the morning
  3. The site is ideal because steep slopes receive more sunlight
  4. The site is unsuitable because water storage and root depth are limited and erosion risk is high Correct answer.

Explanation

Shallow soil over bedrock restricts rooting depth and water storage, while the steep slope increases runoff and erosion. Together these conditions make the site poorly suited to most field crops.

Question 17Soil Science and Soil Management

Which soil particle size fraction holds the greatest amount of plant-available water and nutrients in most soils?

  1. Clay Correct answer.
  2. Coarse sand
  3. Gravel
  4. Fine sand

Explanation

Clay particles are extremely small and carry negative surface charges, giving them a very large surface area relative to their mass. This surface area allows clay to adsorb water and nutrient cations, making it the fraction that contributes most to water and nutrient retention. Sand and gravel have far less surface area and hold little water or nutrients.

Question 18Soil Science and Soil Management

A soil sample feels smooth and sticky when wet and can be moulded into a long ribbon. Which texture class does this describe?

  1. Clay Correct answer.
  2. Loamy sand
  3. Sandy loam
  4. Sandy clay loam

Explanation

The ribbon test relies on the cohesive, plastic behaviour of clay when moistened. A long flexible ribbon that holds together indicates a high clay content, which is the defining characteristic of a clay texture. Sandy soils feel gritty and break apart rather than forming a ribbon.

Question 19Soil Science and Soil Management

Which soil structure type is most favourable for root growth and water movement in arable soils?

  1. Platy structure
  2. Granular structure Correct answer.
  3. Columnar structure
  4. Massive structure

Explanation

Granular structure consists of small, rounded, porous aggregates that create a good balance of large and small pores. This supports root penetration, aeration and water infiltration while still retaining moisture. Massive, platy and columnar structures restrict these processes.

Question 20Soil Science and Soil Management

Which process describes the loss of topsoil by wind or water from bare, sloping land?

  1. Salinisation
  2. Erosion Correct answer.
  3. Compaction
  4. Leaching

Explanation

Erosion is the detachment and transport of soil particles by an erosive agent such as wind or flowing water. Bare, sloping land is especially vulnerable because there is no vegetation cover to intercept rain or hold particles. Leaching, salinisation and compaction are different soil degradation processes.

Question 21Soil Science and Soil Management

Which practice is the most direct way to reduce soil erosion on a sloping cultivated field?

  1. Planting a cover crop between rows Correct answer.
  2. Burning crop residues after harvest
  3. Ploughing up and down the slope
  4. Increasing the depth of tillage

Explanation

A cover crop shields the soil surface from raindrop impact and roots bind particles together, reducing both detachment and transport. This is a direct physical barrier against erosion. Ploughing up and down the slope and removing residues both expose soil and accelerate loss.

Question 22Soil Science and Soil Management

Which soil property is measured by a pH meter or pH indicator test?

  1. Soil bulk density
  2. Soil infiltration rate
  3. Soil organic matter content
  4. Soil acidity or alkalinity Correct answer.

Explanation

Soil pH measures the concentration of hydrogen ions in the soil solution, expressing acidity or alkalinity on a scale. A pH meter or colour indicator reacts to these ions. Bulk density, organic matter and infiltration rate are measured by different methods entirely.

Question 23Soil Science and Soil Management

Which material is most commonly added to raise the pH of an acidic soil?

  1. Farmyard manure
  2. Ammonium sulphate
  3. Gypsum
  4. Agricultural lime Correct answer.

Explanation

Agricultural lime, mainly calcium carbonate, neutralises soil acidity by reacting with hydrogen ions and raising pH. It is the standard amendment for acid soils. Gypsum adds calcium without raising pH, and ammonium sulphate is an acidifying fertiliser.

Question 24Soil Science and Soil Management

Which soil organism group is chiefly responsible for breaking down dead plant residues into humus?

  1. Termites
  2. Earthworms
  3. Bacteria and fungi Correct answer.
  4. Nematodes

Explanation

Bacteria and fungi are the main decomposers, secreting enzymes that break down complex organic compounds into simpler substances and humus. They perform the bulk of biochemical decomposition in soil. Larger organisms such as earthworms fragment residues but rely on microbes for the chemical breakdown.

Question 25Soil Science and Soil Management

A farmer wants to improve the water-holding capacity and nutrient status of a sandy soil. Which addition is most appropriate?

  1. Well-decomposed manure or compost Correct answer.
  2. Coarse gravel
  3. Fresh sawdust
  4. River sand

Explanation

Well-decomposed manure or compost adds organic matter, which increases the soil's ability to hold water and exchange nutrients. Sandy soils are naturally low in both, so organic amendments address the main limitation. Gravel, sand and fresh sawdust do not supply this benefit.

Question 26Soil Science and Soil Management

Why does continuous cultivation without organic inputs usually reduce soil organic matter over time?

  1. Cultivation adds too much carbon to the soil
  2. Tillage speeds decomposition and removes residues, so losses exceed additions Correct answer.
  3. Ploughing stops microbial activity completely
  4. Crops remove all the clay from the soil

Explanation

Tillage aerates the soil and breaks up aggregates, exposing protected organic matter to microbial decomposition. At the same time, harvest removes plant material that would otherwise return carbon to the soil. When losses exceed additions, organic matter declines.

Question 27Soil Science and Soil Management

Which soil water category is most readily taken up by plant roots?

  1. Water held in large macropores after rain
  2. Gravitational water
  3. Hygroscopic water
  4. Capillary water Correct answer.

Explanation

Capillary water is held in the small and medium pores by surface tension at tensions the plant can overcome. It is the main reserve of water available to roots. Gravitational water drains away quickly, and hygroscopic water is bound so tightly that plants cannot extract it.

Question 28Soil Science and Soil Management

A soil test reports a cation exchange capacity of 3 cmol/kg, and the farmer plans to apply potassium fertiliser. What does this low CEC imply for management?

  1. Potassium is likely to leach, so smaller, more frequent applications are better Correct answer.
  2. Potassium will be held strongly and applied once for many seasons
  3. The soil will fix potassium permanently and no fertiliser is needed
  4. The soil has excess clay and should be drained

Explanation

CEC reflects the number of negatively charged sites that hold nutrient cations. A low CEC means few retention sites, so applied potassium can be leached by rainfall or irrigation. Splitting applications into smaller, more frequent doses reduces leaching losses.

Question 29Soil Science and Soil Management

Which statement best explains why heavy machinery traffic on wet soil reduces crop yields?

  1. It raises the cation exchange capacity
  2. It increases pore space and aeration
  3. It increases the clay fraction of the soil
  4. It compacts the soil, reducing pores for air, water and roots Correct answer.

Explanation

Wet soil is weak, so the weight of machinery squeezes particles together and collapses pores. This compaction reduces aeration, infiltration and root penetration, which restricts growth. Compaction does not change the clay fraction or increase exchange capacity.

Question 30Soil Science and Soil Management

Which practice best conserves soil moisture in a dryland field during the dry season?

  1. Deep ploughing to expose subsoil
  2. Maintaining a surface mulch of crop residues Correct answer.
  3. Removing all plant cover to allow drying
  4. Compacting the surface into a hard crust

Explanation

A surface mulch shades the soil, lowers temperature and reduces evaporation from the surface layer. It also protects the soil from wind and rain. Exposing or compacting the surface increases water loss or restricts infiltration.

Question 31Soil Science and Soil Management

Which nutrient is most likely to become deficient in a waterlogged soil, and why?

  1. Nitrogen, because denitrification converts nitrate to nitrogen gas Correct answer.
  2. Potassium, because it is fixed by clay
  3. Calcium, because it leaches rapidly
  4. Phosphorus, because it becomes insoluble

Explanation

When soil pores fill with water, oxygen is depleted and anaerobic bacteria use nitrate as an electron acceptor. This denitrification converts nitrate to nitrogen gas, which escapes to the atmosphere. The result is a rapid loss of available nitrogen.

Question 32Soil Science and Soil Management

Which statement correctly describes the effect of a soil with a high proportion of clay on drainage and aeration?

  1. It drains rapidly and is well aerated
  2. It behaves exactly like a sandy soil
  3. It has no pores and cannot hold water
  4. It drains slowly and may become waterlogged Correct answer.

Explanation

Clay soils have many very small pores but few large ones, so water moves through them slowly. This slow drainage can lead to waterlogging and poor aeration after heavy rain. The soil still holds substantial water; it simply releases and transmits it slowly.

Question 33Soil Science and Soil Management

Which soil conservation measure is a structural method rather than an agronomic method?

  1. Mulching
  2. Green manuring
  3. Contour ploughing Correct answer.
  4. Crop rotation

Explanation

Structural measures involve shaping the land or building physical barriers to control runoff, such as contour ploughing, terraces and bunds. Agronomic measures rely on vegetation management, including rotation, mulching and green manuring. Contour ploughing works by following the land contour to slow water movement.

Question 34Soil Science and Soil Management

A farmer applies ammonium-based fertiliser repeatedly to an already acidic soil. What is the likely long-term effect on soil pH?

  1. pH will rise and then stabilise at alkaline levels
  2. pH will remain unchanged
  3. pH will rise towards neutral
  4. pH will fall further Correct answer.

Explanation

Ammonium-based fertilisers release hydrogen ions when ammonium is nitrified in the soil, which is an acidifying process. Repeated use on an already acidic soil therefore lowers pH further. Liming is usually needed to counteract this acidification.

Question 35Soil Science and Soil Management

Which feature distinguishes a soil profile's A horizon from its B horizon?

  1. The A horizon is the topsoil richest in organic matter, while the B horizon is a subsoil of accumulation Correct answer.
  2. The A horizon is always sandy, while the B horizon is always clay
  3. The A horizon lies below the B horizon in all soils
  4. The A horizon is bedrock, while the B horizon is the parent material

Explanation

The A horizon is the surface mineral layer where organic matter accumulates and biological activity is greatest. The B horizon lies below it and commonly shows accumulation of clay, iron or other materials leached from above. The A horizon is always above the B horizon.

Question 36Soil Science and Soil Management

In a soil with a bulk density of 1.6 g/cm3 and a particle density of 2.65 g/cm3, what is the approximate total porosity?

  1. 26 percent
  2. 16 percent
  3. 60 percent
  4. 40 percent Correct answer.

Explanation

Porosity equals one minus the ratio of bulk density to particle density, so 1 minus 1.6 divided by 2.65 gives about 0.40, or 40 percent. This calculation reflects the proportion of the soil volume occupied by pores. Higher bulk density means lower porosity.

Question 37Soil Science and Soil Management

A laboratory reports that a soil has 35 percent clay, 55 percent sand and 10 percent silt. Using the standard texture triangle, which class is most likely?

  1. Sandy loam
  2. Clay
  3. Silty clay
  4. Sandy clay loam Correct answer.

Explanation

A soil with roughly half sand, a third clay and little silt falls in the sandy clay loam class on the texture triangle. It has enough clay for stickiness but enough sand to feel gritty and to drain moderately. Classes with high silt or very high clay do not fit these proportions.

Question 38Soil Science and Soil Management

Two soils receive the same rainfall, but soil X loses far more nitrate to groundwater than soil Y. Soil X is sandy with low organic matter, and soil Y is a clay loam. Which explanation is most consistent with this result?

  1. Soil X has fewer exchange sites and faster drainage, so nitrate moves below the root zone Correct answer.
  2. Soil Y has larger pores, so water bypasses its roots
  3. Soil X has higher CEC, so it retains more nitrate
  4. Soil Y is more acidic, so it leaches less nitrate

Explanation

Nitrate is an anion and is not held on negatively charged exchange sites, so it moves with drainage water. A sandy soil with low organic matter and low CEC drains quickly and retains little water or nitrate, allowing nitrate to move below the root zone. The clay loam holds more water and slows downward movement.

Question 39Soil Science and Soil Management

A farmer's field shows patchy, stunted growth with purple-tinged leaves, and a soil test shows adequate total phosphorus but a pH of 4.8. Which interpretation is most reasonable?

  1. The crop is suffering from nitrogen excess
  2. Phosphorus is present but largely unavailable because of strong acidity and aluminium activity Correct answer.
  3. The soil has no phosphorus at all
  4. The purple colour indicates potassium deficiency

Explanation

In strongly acidic soils, phosphorus reacts with aluminium and iron to form insoluble compounds, so total phosphorus can be adequate while available phosphorus is low. Raising pH by liming reduces this fixation and improves availability. Purple leaves are a common symptom of phosphorus deficiency.

Question 40Soil Science and Soil Management

A sodic soil with high exchangeable sodium and poor structure is to be reclaimed. Which treatment combination is most appropriate?

  1. Apply gypsum and provide drainage to leach the displaced sodium Correct answer.
  2. Apply lime and increase tillage depth
  3. Apply muriate of potash and flood the field without drainage
  4. Apply ammonium sulphate and stop irrigation

Explanation

Gypsum supplies calcium, which replaces sodium on the exchange complex, and drainage is needed to carry the displaced sodium out of the root zone. Without drainage, the sodium remains in the profile. Liming does not address sodium and can worsen sodicity.

Question 41Crop Production and Husbandry

Which tillage practice is most effective for conserving soil moisture in a dryland crop field in Botswana?

  1. Keeping a mulch cover over the soil surface Correct answer.
  2. Ploughing deeply and leaving the surface bare
  3. Compacting the soil with heavy machinery
  4. Burning crop residues after harvest

Explanation

A surface mulch shields the soil from direct sun and reduces evaporation, while also softening the impact of raindrops. Bare soil loses moisture quickly and is more exposed to erosion. Retaining residues therefore conserves water for the following crop.

Question 42Crop Production and Husbandry

A farmer wants to reduce soil erosion on a sloping field. Which measure directly slows the movement of runoff down the slope?

  1. Removing all vegetation from the field
  2. Planting contour strips of grass across the slope Correct answer.
  3. Ploughing in straight lines up and down the slope
  4. Increasing the slope by terracing downhill

Explanation

Contour strips follow the land contour and act as barriers that slow runoff and trap soil particles. Ploughing up and down the slope creates channels that speed water downhill. Vegetation cover is central to controlling erosion on sloping land.

Question 43Crop Production and Husbandry

Which of the following is a leguminous crop commonly grown in Botswana that adds nitrogen to the soil?

  1. Groundnut Correct answer.
  2. Sunflower
  3. Sorghum
  4. Maize

Explanation

Legumes such as groundnut form nodules with nitrogen-fixing bacteria that convert atmospheric nitrogen into forms usable by plants. Cereals like maize and sorghum and oil crops like sunflower do not fix nitrogen. Including legumes in a rotation therefore improves soil fertility.

Question 44Crop Production and Husbandry

What is the main purpose of applying kraal manure to a crop field?

  1. To kill weeds growing in the field
  2. To make the soil more acidic
  3. To supply nutrients and improve soil structure Correct answer.
  4. To reduce the water-holding capacity of the soil

Explanation

Kraal manure supplies plant nutrients such as nitrogen and phosphorus and adds organic matter that improves soil structure and water retention. It is not a herbicide and does not aim to acidify soil. Its role is both nutritional and physical improvement of the soil.

Question 45Crop Production and Husbandry

A farmer notices that maize seedlings are being cut off at ground level during the night. Which pest is most likely responsible?

  1. Leaf rust fungus
  2. Cutworm Correct answer.
  3. Stalk borer
  4. Aphids

Explanation

Cutworms feed at night and sever young seedlings at or just below the soil surface, causing them to fall over. Aphids suck sap from leaves, stalk borers tunnel into stems, and rust is a fungal disease. The cutting of stems at ground level is characteristic of cutworm damage.

Question 46Crop Production and Husbandry

Which practice best helps to control weeds in a maize field before the crop emerges?

  1. Increasing the plant spacing to reduce competition
  2. Spraying the field with a fungicide
  3. Applying a pre-emergence herbicide to the soil Correct answer.
  4. Hand weeding after the maize has flowered

Explanation

Pre-emergence herbicides are applied to the soil before the crop and weeds emerge and prevent early weed establishment. Weeding after flowering is too late to protect yield, and fungicides do not affect weeds. Wider spacing usually increases weed competition rather than reducing it.

Question 47Crop Production and Husbandry

Which type of seed should a farmer select for planting to obtain uniform germination and strong seedlings?

  1. Seed collected from diseased plants
  2. Seed saved from the previous harvest without cleaning
  3. Grain bought from a market for food
  4. Certified seed of a recommended variety Correct answer.

Explanation

Certified seed is tested for germination, purity and freedom from pests and diseases, giving uniform stands. Unclean farm-saved seed and food grain may carry disease, weed seeds or poor germination. Selecting certified seed of an adapted variety is a basic step for good crop establishment.

Question 48Crop Production and Husbandry

In a crop rotation plan, which sequence best helps to break the life cycle of a soil-borne disease?

  1. Growing the same crop on the same plot every season
  2. Leaving the plot bare with no crop for many years
  3. Alternating crops from different plant families on the plot Correct answer.
  4. Growing two varieties of the same crop in succession

Explanation

Crop rotation with crops from different families deprives pathogens specific to one crop of their host, reducing their build-up in the soil. Continuous cropping of the same species allows pathogens to multiply. Rotation is therefore a key cultural control for soil-borne diseases.

Question 49Crop Production and Husbandry

A farmer applies 200 kg of a compound fertiliser containing 10% nitrogen. How much nitrogen is applied to the field?

  1. 200 kg
  2. 20 kg Correct answer.
  3. 10 kg
  4. 2 kg

Explanation

The amount of nutrient is found by multiplying the mass of fertiliser by the percentage of the nutrient. Here 200 kg multiplied by 10% gives 20 kg of nitrogen. This calculation helps the farmer match fertiliser application to crop requirements.

Question 50Crop Production and Husbandry

Why is it important to apply nitrogen fertiliser to a maize crop in split doses rather than all at planting?

  1. To increase the acidity of the soil
  2. To make the fertiliser cheaper to buy
  3. To prevent the maize from flowering
  4. To reduce leaching losses and match nitrogen supply to crop demand Correct answer.

Explanation

Nitrogen is mobile in the soil and can be leached by rain before the crop needs it. Splitting applications places nitrogen where and when the growing crop can use it most efficiently. This improves fertiliser use efficiency and reduces losses.