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RBSE Prav Voc Agriculture study materials
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RBSE Prav Voc Agriculture practice questions

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Question 1Agricultural Science Fundamentals

Which soil property is measured directly by a soil thermometer inserted at ploughing depth?

  1. Soil temperature Correct answer.
  2. Soil pH
  3. Soil electrical conductivity
  4. Soil bulk density

Explanation

A soil thermometer responds only to thermal conditions at the depth of insertion, so it quantifies soil temperature. pH requires an electrode or colour indicator, conductivity requires a conductivity cell, and bulk density is obtained by weighing a known oven-dry volume of soil.

Question 2Agricultural Science Fundamentals

A farmer wants to reduce wind erosion on a bare sandy field. Which practice addresses the problem most directly?

  1. Flood irrigation before sowing
  2. Planting a shelterbelt of trees on the windward side Correct answer.
  3. Applying lime to raise soil pH
  4. Deep ploughing to bury surface residue

Explanation

Wind erosion begins when wind speed at the soil surface exceeds the threshold needed to detach and move particles. A shelterbelt reduces wind velocity at ground level, so it directly limits detachment and transport. Liming, deep ploughing and flood irrigation change chemistry, residue placement or moisture but do not reduce the erosive wind force.

Question 3Agricultural Science Fundamentals

Which nutrient is taken up by leguminous crops mainly through symbiotic nitrogen fixation rather than from soil solution?

  1. Sulphur
  2. Phosphorus
  3. Potassium
  4. Nitrogen Correct answer.

Explanation

Rhizobia in root nodules reduce atmospheric dinitrogen to ammonia that the host plant assimilates, so legumes can meet much of their nitrogen demand this way. Phosphorus, potassium and sulphur are not fixed from the atmosphere and must come from soil or fertiliser.

Question 4Agricultural Science Fundamentals

In a seed germination test, what does the term germination percentage describe?

  1. The average fresh weight of the seedlings produced
  2. The proportion of seeds that absorbed water within 24 hours
  3. The number of days until the first seedling emerged
  4. The proportion of tested seeds that produced normal seedlings Correct answer.

Explanation

Germination percentage is the number of normal seedlings counted at the end of the test expressed as a percentage of the seeds sown. It is a viability measure used to set sowing rates. Imbibition, seedling weight and time to first emergence describe other aspects of seed behaviour.

Question 5Agricultural Science Fundamentals

Which implement is designed primarily to invert and bury crop residue in the topsoil?

  1. Roller
  2. Mouldboard plough Correct answer.
  3. Cultivator
  4. Disc harrow

Explanation

A mouldboard plough cuts a furrow slice and turns it over, burying surface residue and weeds. Harrows, cultivators and rollers stir, level or firm the soil without full inversion.

Question 6Agricultural Science Fundamentals

A crop is described as having a C4 photosynthetic pathway. Which characteristic is typical of such a crop?

  1. Growth that is restricted to cool shaded conditions
  2. Absence of stomatal regulation of water loss
  3. Efficient photosynthesis at high temperature and light intensity Correct answer.
  4. Dependence on photorespiration for carbon gain

Explanation

C4 plants concentrate carbon dioxide at Rubisco through a biochemical pump, which suppresses photorespiration and supports high photosynthetic rates under hot, bright conditions. They are not shade specialists, they avoid rather than depend on photorespiration, and they still regulate stomata.

Question 7Agricultural Science Fundamentals

Which practice best reduces nitrate leaching from a field after harvest?

  1. Leaving the field bare and uncultivated
  2. Burning the crop residue in the field
  3. Applying urea immediately before heavy rain
  4. Sowing a cover crop that takes up residual nitrogen Correct answer.

Explanation

A rapidly establishing cover crop absorbs residual nitrate from the soil profile and holds it, reducing the amount that can move below the root zone with drainage water. Bare soil, fertiliser applied before heavy rain and residue burning all leave or increase mobile nitrate at risk of leaching.

Question 8Agricultural Science Fundamentals

What is the main purpose of a nursery bed in vegetable production?

  1. Holding livestock away from cropland
  2. Raising healthy seedlings for later transplanting Correct answer.
  3. Storing harvested produce before sale
  4. Testing soil pH before field preparation

Explanation

A nursery bed is a managed, usually raised and protected area where seeds are sown densely to produce uniform seedlings that are later transplanted to the field. It allows careful watering, shading and pest control during the vulnerable early stage. It is not a storage, testing or livestock facility.

Question 9Agricultural Science Fundamentals

A soil sample from a field reads pH 5.2. Which interpretation is most appropriate for most arable crops?

  1. The soil is strongly alkaline and gypsum may be needed
  2. The soil is strongly acidic and lime may be needed Correct answer.
  3. The soil is saline and needs leaching
  4. The soil is neutral and needs no amendment

Explanation

On the standard pH scale, values well below 6 indicate acidity; 5.2 is strongly acidic for most arable crops and can restrict nutrient availability and root growth. Alkaline soils lie above about 7.5, neutrality is near 7, and salinity is diagnosed from electrical conductivity rather than pH.

Question 10Agricultural Science Fundamentals

In a crop rotation, why is a cereal usually followed by a legume rather than by another cereal?

  1. The cereal residues always raise soil pH for the legume
  2. The legume adds fixed nitrogen and interrupts cereal-specific pests and diseases Correct answer.
  3. The legume requires more nitrogen fertiliser than the cereal
  4. The legume cannot grow in the same season as a cereal

Explanation

Alternating a cereal with a legume diversifies the root environment, breaking the build-up of cereal pathogens and pests, while the legume supplies biologically fixed nitrogen for the following crop. A cereal-after-cereal sequence tends to deplete nitrogen and favour pathogen carry-over.

Question 11Agricultural Science Fundamentals

A seed lot has 90 percent germination and 95 percent purity. What is the pure live seed (PLS) percentage?

  1. 90.0 percent
  2. 92.5 percent
  3. 85.5 percent Correct answer.
  4. 95.0 percent

Explanation

Pure live seed percentage is calculated by multiplying germination percentage by purity percentage and dividing by 100, so 90 x 95 / 100 gives 85.5 percent. This value is used to adjust sowing rate so that the desired number of viable seeds is placed per unit area.

Question 12Agricultural Science Fundamentals

Which irrigation method generally gives the highest application efficiency on a level field with limited water supply?

  1. Flood irrigation
  2. Drip irrigation Correct answer.
  3. Border strip irrigation
  4. Furrow irrigation

Explanation

Drip irrigation delivers water slowly and directly to the root zone, minimising evaporation, deep percolation and runoff, so it typically achieves the highest application efficiency. Flood, furrow and border methods depend on gravity flow over the surface and lose more water to evaporation, runoff and uneven infiltration.

Question 13Agricultural Science Fundamentals

Which insect order includes the majority of serious defoliating caterpillars in field crops?

  1. Hemiptera
  2. Coleoptera
  3. Orthoptera
  4. Lepidoptera Correct answer.

Explanation

Lepidoptera is the order of moths and butterflies, and their larval stages are caterpillars, which are the classic defoliators of field and vegetable crops. Coleoptera covers beetles, Hemiptera covers true bugs with piercing-sucking mouthparts, and Orthoptera covers grasshoppers and crickets.

Question 14Agricultural Science Fundamentals

A fungal disease spreads rapidly in a crop after several days of high humidity and leaf wetness. Which control measure acts earliest in the disease cycle?

  1. Preventive fungicide spray before infection occurs Correct answer.
  2. Curative spray after symptoms are widespread
  3. Rogueing infected plants after the epidemic
  4. Deep ploughing after harvest

Explanation

Fungal spores need free moisture to germinate and infect, so a preventive protectant spray applied before the humid period blocks the infection step rather than trying to arrest an established epidemic. Curative sprays, roguing and post-harvest ploughing act later in the cycle and cannot prevent the initial spread.

Question 15Agricultural Science Fundamentals

Which factor most directly determines the safe storage life of dry grain?

  1. Seed rate used at sowing
  2. Grain colour and thousand-grain weight
  3. Grain moisture content and temperature Correct answer.
  4. Field size and row spacing

Explanation

Moulds and insects in stored grain develop fastest when moisture content and temperature are high, so these two variables set the safe storage period. Colour, grain weight, field layout and sowing rate do not govern deterioration in store.

Question 16Agricultural Science Fundamentals

Which hormone is chiefly responsible for the ripening of climacteric fruits such as banana and tomato?

  1. Auxin
  2. Abscisic acid
  3. Ethylene Correct answer.
  4. Gibberellin

Explanation

Ethylene is a gaseous plant hormone that triggers the ripening sequence in climacteric fruits, including colour change, softening and sugar development. Auxins and gibberellins mainly regulate growth and elongation, while abscisic acid is associated with stress responses and dormancy.

Question 17Agricultural Science Fundamentals

A farmer applies 100 kg of urea (46 percent nitrogen). How much nitrogen is applied?

  1. 46 kg Correct answer.
  2. 54 kg
  3. 100 kg
  4. 23 kg

Explanation

Urea contains 46 percent nitrogen by mass, so 100 kg of urea supplies 100 x 0.46, which equals 46 kg of nitrogen. The remaining 54 kg is the carrier portion of the fertiliser, not nitrogen.

Question 18Agricultural Science Fundamentals

Which practice is most appropriate for controlling a weed that has developed resistance to a single herbicide group?

  1. Increasing the dose of the same herbicide every season
  2. Applying the same herbicide more frequently at lower doses
  3. Using only mechanical cultivation and abandoning herbicides permanently
  4. Rotating to herbicides with different modes of action and integrating non-chemical methods Correct answer.

Explanation

Resistance management relies on reducing selection pressure by using herbicides with different modes of action in rotation and combining them with cultural, mechanical and biological controls. Repeated use of the same group, at any dose or frequency, selects further for resistant individuals.

Question 19Agricultural Science Fundamentals

Which soil structure type is generally most favourable for root growth and drainage in arable topsoil?

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

Explanation

Granular or crumb structure consists of small, rounded aggregates with abundant pore space, giving good aeration, water infiltration and root penetration. Massive, platy and columnar structures are either compact, horizontally layered or associated with sodic subsoils, all of which restrict roots and drainage.

Question 20Agricultural Science Fundamentals

A crop shows interveinal chlorosis on older leaves first. Which nutrient deficiency is most likely?

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

Explanation

Magnesium is a mobile nutrient that is translocated from older to younger tissue, so deficiency appears first as interveinal chlorosis on older leaves. Iron, calcium and boron are relatively immobile, so their deficiency symptoms typically appear first on young leaves or growing points.

Question 21Agricultural Science Fundamentals

In a randomised complete block design with four replications, why are treatments randomised within each block?

  1. To increase the number of treatments tested
  2. To guarantee that all treatments receive identical soil moisture
  3. To eliminate the need for replication
  4. To remove block-to-block variation from the treatment comparison Correct answer.

Explanation

Blocking groups plots of similar conditions, and randomising treatments within each block ensures that the block effect is accounted for in the analysis, so treatment differences are estimated free of block-to-block variation. Randomisation does not equalise soil moisture, increase treatment numbers or replace replication.

Question 22Agricultural Science Fundamentals

Why is biological nitrogen fixation by rhizobia inhibited when a legume is heavily fertilised with nitrate?

  1. Nitrate raises soil pH above the tolerance of rhizobia
  2. Nitrate uptake supplies nitrogen that represses nodulation and nitrogenase activity Correct answer.
  3. Nitrate directly destroys the bacteroids inside existing nodules
  4. Nitrate blocks photosynthesis in the legume leaves

Explanation

When nitrate is readily available, the plant can meet its nitrogen demand from uptake, and the resulting nitrogen status suppresses nodule initiation and nitrogenase activity, saving the carbon cost of fixation. Nitrate does not physically destroy bacteroids, act mainly through pH, or block photosynthesis.

Question 23Agricultural Science Fundamentals

A farmer must choose between a high-yielding variety with high fertiliser demand and a local variety with lower yield but stable performance. Which criterion is most important in a low-input, risk-prone environment?

  1. Maximum yield recorded at the research station
  2. Seed size of the variety
  3. Number of leaves per plant at flowering
  4. Yield stability and performance under low input conditions Correct answer.

Explanation

In low-input, risk-prone environments the variety must perform reliably with limited fertiliser and water, so stability and low-input adaptation matter more than maximum potential yield. Station yields achieved with high inputs, seed size and leaf counts are poor predictors of farm-level reliability.

Question 24Agricultural Science Fundamentals

Why does continuous monoculture of the same crop often lead to a decline in yield even when fertiliser is applied?

  1. Pathogens, pests and weed flora specific to the crop build up in the soil Correct answer.
  2. The crop stops photosynthesising after several generations
  3. The soil loses all its clay fraction within a few seasons
  4. Fertiliser becomes chemically inert after repeated use

Explanation

Repeated cropping of one species favours organisms and weeds adapted to that host, so soil-borne pathogens, nematodes and problem weeds accumulate and reduce yield despite adequate nutrition. Fertiliser does not become inert, clay is not lost within a few seasons, and the photosynthetic capacity of the crop is not affected by cropping history.

Question 25Agricultural Science Fundamentals

A sprinkler system applies 30 mm of water, but a catch-can test shows an average of 24 mm reaching the cans. What is the application efficiency?

  1. 125 percent
  2. 60 percent
  3. 80 percent Correct answer.
  4. 75 percent

Explanation

Application efficiency is the water reaching the target divided by the water applied, expressed as a percentage: 24 divided by 30 multiplied by 100 gives 80 percent. The remaining 20 percent is lost to evaporation, wind drift and uneven distribution.

Question 26Agricultural Science Fundamentals

A farmer wants to improve the physical condition of a compacted sandy loam field over several seasons. Which input adds the most organic matter per tonne applied and is most commonly recommended as a bulky soil amendment in arable farming?

  1. Gypsum powder
  2. Urea fertiliser
  3. Lime
  4. Well-rotted farmyard manure Correct answer.

Explanation

Bulky organic materials such as well-rotted farmyard manure add large amounts of organic carbon, which improves aggregation, water-holding capacity and biological activity in a compacted sandy loam. Mineral fertilisers and amendments supply nutrients or alter chemistry but do not rebuild soil structure through organic matter.

Question 27Agricultural Science Fundamentals

A cereal crop is to be sown with a seed drill at a target plant population of 250 plants per square metre. If the seed lot has 95 percent germination and the field typically loses about 20 percent of emerged plants to pests and seedling mortality, roughly how many viable seeds per square metre should the drill place?

  1. About 330 seeds per square metre Correct answer.
  2. About 400 seeds per square metre
  3. About 210 seeds per square metre
  4. About 250 seeds per square metre

Explanation

The target population must be divided by the expected survival fraction: 0.95 germination multiplied by 0.80 field survival gives 0.76, and 250 divided by 0.76 is about 329 seeds per square metre. Sowing at the target plant number itself would leave the final stand well short of 250 plants.

Question 28Agricultural Science Fundamentals

A crop of maize shows pale striping between the veins of the middle leaves while the leaf margins remain green, and the field has recently been irrigated heavily on a sandy soil. Which nutrient deficiency best fits this pattern?

  1. Magnesium Correct answer.
  2. Potassium
  3. Phosphorus
  4. Calcium

Explanation

Interveinal chlorosis on middle to older leaves is the classic symptom of magnesium deficiency, because magnesium is mobile in the plant and is redistributed from older tissue. Heavy irrigation on sandy soils also increases leaching losses of magnesium, matching the field history.

Question 29Agricultural Science Fundamentals

A grower stores harvested onions for several months and finds heavy losses from neck rot. Which storage and pre-storage practice most directly reduces this problem?

  1. Washing the bulbs in water immediately after lifting
  2. Storing bulbs in sealed polythene bags at high humidity
  3. Curing the bulbs thoroughly before storage and keeping them cool and dry with good ventilation Correct answer.
  4. Storing bulbs in thick layers in a warm, humid shed

Explanation

Neck rot fungi enter mainly through the neck and damaged tissue, so proper curing allows the neck to dry and seal before storage. Cool, dry, well-ventilated conditions then slow fungal growth and keep bulb surfaces dry throughout the storage period.

Question 30Agricultural Science Fundamentals

A field has been in continuous wheat for many years and now shows declining yields, increasing take-all damage and poor soil structure despite adequate fertiliser. Which change to the cropping plan best addresses all three problems at once?

  1. Applying a broad-spectrum soil fumigant before every wheat crop
  2. Increasing the nitrogen rate on the wheat each season
  3. Switching to a grass ley or a break crop in rotation with the wheat Correct answer.
  4. Sowing a denser wheat stand to shade out weeds

Explanation

A rotation break with a non-host crop or a grass ley interrupts the build-up of soil-borne pathogens such as take-all and improves soil structure through different root systems and organic matter return. Continuous wheat maintains the pathogen population and degrades structure, so more fertiliser or denser sowing cannot correct the underlying cause.

Question 31Crop Production and Management

Which practice is used to break the hardpan of a field before sowing a deep-rooted crop like cotton?

  1. Ridging
  2. Mulching
  3. Subsoiling Correct answer.
  4. Puddling

Explanation

Subsoiling loosens compacted soil layers below the normal ploughing depth without inverting the topsoil, allowing deep-rooted crops such as cotton to develop roots freely. Puddling destroys structure and creates a compacted layer, which is the opposite of what is needed. It is therefore the correct pre-sowing operation here.

Question 32Crop Production and Management

A farmer wants a legume in the rotation to improve soil nitrogen. Which crop should be chosen?

  1. Cluster bean Correct answer.
  2. Pearl millet
  3. Sorghum
  4. Maize

Explanation

Cluster bean (guar) is a legume and forms root nodules with Rhizobium bacteria that fix atmospheric nitrogen, adding nitrogen to the soil when residues are incorporated. Pearl millet, sorghum and maize are all cereals that take up nitrogen and do not fix it. Including a legume therefore raises available nitrogen for the following crop.

Question 33Crop Production and Management

Which of the following is the correct seed rate consideration when sowing a crop with a larger seed size?

  1. Seed rate is unaffected by seed size
  2. Seed rate increases because each seed weighs more Correct answer.
  3. Seed rate is fixed for all crops at 100 kg per hectare
  4. Seed rate decreases because fewer plants are needed

Explanation

Seed rate is normally set to achieve a target plant population, so when individual seeds are heavier a greater weight of seed is required to sow the same number of seeds per unit area. Seed size therefore raises the weight-based seed rate. Seed rates are crop-specific and cannot be fixed at one value for all crops.

Question 34Crop Production and Management

Which irrigation method is most suitable for a closely spaced row crop on sandy soil with limited water supply?

  1. Flood irrigation
  2. Drip irrigation Correct answer.
  3. Furrow irrigation
  4. Basin irrigation

Explanation

Drip irrigation delivers water slowly and directly to the root zone, minimising evaporation, deep percolation and runoff, which suits sandy soils and scarce water. Flood, furrow and basin methods apply large volumes over the surface and lose much water through percolation in sandy soil. Drip therefore gives the highest water-use efficiency in this situation.

Question 35Crop Production and Management

Which of the following is a major function of adding organic manure to crop soil?

  1. It eliminates the need for any mineral fertiliser
  2. It raises soil pH sharply like lime
  3. It kills soil-borne pathogens directly
  4. It improves soil structure and water-holding capacity Correct answer.

Explanation

Organic manure adds humus that binds soil particles into stable aggregates, improving aeration, infiltration and water-holding capacity. It supplies nutrients slowly and in modest amounts, so it cannot replace mineral fertiliser entirely or act as a disinfectant. Its main agronomic benefit is physical improvement of the soil.

Question 36Crop Production and Management

Which weed is a common parasitic weed of crops such as sorghum and sugarcane?

  1. Cyperus rotundus
  2. Echinochloa colona
  3. Striga Correct answer.
  4. Parthenium hysterophorus

Explanation

Striga, known as witchweed, is a root parasite that attaches to the roots of host crops such as sorghum, millet and sugarcane and draws water and nutrients from them. The other species listed are ordinary weeds that compete for resources but do not parasitise crop roots. Recognising the parasitic habit helps in choosing control measures.

Question 37Crop Production and Management

Which of the following crops is a kharif season crop in most of India?

  1. Chickpea
  2. Mustard
  3. Wheat
  4. Paddy Correct answer.

Explanation

Kharif crops are sown with the onset of the monsoon and harvested in autumn, and paddy is a typical kharif crop in most regions. Wheat, mustard and chickpea are rabi crops grown in the cooler post-monsoon season. Season classification is based on the crop's temperature and moisture requirements.

Question 38Crop Production and Management

Which practice directly reduces post-harvest losses of grains during storage?

  1. Storing freshly harvested grain at high moisture
  2. Drying grain to safe moisture before storage Correct answer.
  3. Mixing fresh and old grain in one bin
  4. Storing grain in open, unsealed bags

Explanation

Grain must be dried to a safe moisture level before storage because high moisture encourages fungal growth, insect attack and heating of the grain mass. Drying reduces respiration and spoilage organisms. Mixing batches or leaving bags open exposes the grain to moisture and pests and increases losses.

Question 39Crop Production and Management

A field has poor drainage and water stands after heavy rain. Which crop choice is most appropriate for such a field?

  1. Mustard
  2. Paddy Correct answer.
  3. Cotton
  4. Chickpea

Explanation

Paddy is well adapted to standing water and waterlogged conditions, so it performs better than dryland crops in a field with poor drainage. Chickpea, cotton and mustard are sensitive to waterlogging and suffer root damage, stunting and yield loss when water stands. Matching crop to field drainage is a basic management decision.

Question 40Crop Production and Management

In a crop rotation, why is it recommended to alternate a cereal with a pulse rather than grow the same cereal continuously?

  1. Pulses always give higher yields than cereals
  2. Cereals cannot be grown in rotation
  3. Continuous cereal cropping builds up the same pests and depletes the same soil nutrients Correct answer.
  4. Pulses require more irrigation than cereals

Explanation

Growing the same cereal repeatedly favours build-up of host-specific pathogens, pests and weeds and removes the same nutrients from the same soil layer. A pulse in the rotation breaks these cycles and adds fixed nitrogen. Alternating crops therefore improves soil fertility and reduces pest pressure.

Question 41Crop Production and Management

A farmer applies urea to a paddy field and the water is drained immediately after application. What is the main nitrogen loss mechanism that is likely to occur?

  1. Leaching and denitrification losses in the drained flooded soil Correct answer.
  2. Volatilisation of ammonia from dry soil
  3. Immobilisation by crop residues
  4. Fixation of nitrogen by Rhizobium

Explanation

Urea hydrolyses to ammonium, which in drained, aerated soil is converted to nitrate and can be leached, and in subsequent flooded conditions nitrate is denitrified to nitrogen gas. Draining soon after application therefore promotes both leaching and denitrification losses. Good water management after top-dressing reduces these losses.

Question 42Crop Production and Management

Which of the following is the correct reason for treating seed with a fungicide before sowing in a crop prone to soil-borne seedling disease?

  1. To protect the germinating seed and seedling from soil-borne pathogens Correct answer.
  2. To supply nitrogen to the seedling
  3. To increase seed germination speed
  4. To increase the seed rate

Explanation

Seed treatment coats the seed with a fungicide that protects it and the emerging seedling against soil-borne pathogens such as damping-off organisms. It does not supply nutrients or directly speed germination, and it does not alter the seed rate. The purpose is disease protection during establishment.

Question 43Crop Production and Management

A farmer wants to control weeds in a broad-leaved crop without harming the crop. Which approach is most appropriate?

  1. Increasing seed rate to suppress weeds only
  2. Spraying a non-selective herbicide over the whole field
  3. Spraying a selective herbicide recommended for that crop Correct answer.
  4. Flooding the field to drown weeds

Explanation

A selective herbicide is formulated to kill target weeds while leaving the crop unharmed when used at the recommended dose and stage. A non-selective herbicide would kill the crop as well, and flooding is not a practical weed-control method for most crops. Selecting the right herbicide and timing is central to chemical weed management.

Question 44Crop Production and Management

Which of the following describes the purpose of puddling in paddy cultivation?

  1. To reduce water percolation by destroying soil structure Correct answer.
  2. To break the hardpan before transplanting
  3. To incorporate organic manure into the soil
  4. To increase soil porosity for root growth

Explanation

Puddling is the churning of wet soil that destroys aggregates and creates a compacted layer beneath the surface, which reduces water percolation losses in paddy fields. It does not increase porosity, and it is not a method of manure incorporation or hardpan breaking. It is specific to lowland rice culture.

Question 45Crop Production and Management

A farmer notices that a crop shows yellowing of older leaves while young leaves remain green. Which nutrient deficiency is most likely?

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

Explanation

Nitrogen is mobile in the plant, so when it is deficient the plant moves nitrogen from older leaves to growing points, causing older leaves to yellow first. Iron, calcium and boron are largely immobile, so their deficiency symptoms appear first on young leaves. This mobility pattern is a useful diagnostic tool.

Question 46Crop Production and Management

Which factor most directly determines the choice of sowing time for a rainfed kharif crop?

  1. Onset of the monsoon rains Correct answer.
  2. Availability of storage bags
  3. Length of the previous crop's stubble
  4. Price of the harvested produce

Explanation

For a rainfed kharif crop, sowing must coincide with the arrival of the monsoon so that seeds germinate and establish with adequate soil moisture. Stubble length, produce price and storage bags do not determine sowing date. Timing sowing with rainfall also reduces the risk of crop failure.

Question 47Crop Production and Management

What is the main advantage of using certified seed over farmer-saved seed?

  1. Certified seed is always cheaper
  2. Certified seed cannot be attacked by pests
  3. Certified seed needs no irrigation
  4. Certified seed has assured genetic purity and germination Correct answer.

Explanation

Certified seed is produced and tested under a quality control system that guarantees genetic purity, germination percentage and freedom from specified weed seeds and diseases. It is generally more expensive than saved seed and still requires irrigation and pest management. The assurance of quality is its main advantage.

Question 48Crop Production and Management

A grower wants to reduce soil erosion on a sloping field while continuing to grow crops. Which combination is most appropriate?

  1. Removing all crop residues after harvest
  2. Clean cultivation up and down the slope
  3. Deep ploughing along the slope
  4. Contour cultivation with a cover crop Correct answer.

Explanation

Contour cultivation follows the slope's contour lines and slows runoff, while a cover crop protects the soil surface from raindrop impact and holds it with roots. Together they reduce erosion effectively. Cultivating up and down the slope, ploughing along the slope, or removing residues all accelerate soil loss.

Question 49Crop Production and Management

In a crop sequence, a farmer grows a short-duration pulse between two main crops. What is this practice called?

  1. Strip cropping
  2. Mixed cropping
  3. Catch cropping Correct answer.
  4. Monocropping

Explanation

Growing a short-duration crop in the interval between two main crops, using available moisture and time, is called catch cropping. Mixed cropping grows two or more crops together, monocropping grows one crop repeatedly, and strip cropping alternates strips of crops mainly for erosion control. The defining feature here is the use of the intervening period.

Question 50Crop Production and Management

Which of the following best explains why deep ploughing is avoided in sandy soils?

  1. It improves the water-holding capacity of sand
  2. It increases organic matter content
  3. It reduces the need for fertiliser
  4. It brings up infertile subsoil and increases moisture loss Correct answer.

Explanation

Sandy soils have little structure and low fertility in the subsoil, so deep ploughing can bring infertile material to the surface and expose moist soil to rapid drying. It does not add organic matter or improve water retention in sand. Shallow, moisture-conserving tillage is preferred for such soils.