← Combined Technical (NG)
Past Questions — 2025
In the universal soil loss equation, the K factor is :
A)
Crop management
B)
Slope
C)
ratio of soil loss with a specific erosion control
D)
Soil erodibility index
The Universal Soil Loss Equation (USLE) is used to predict the long-term average annual rate of erosion. The formula is A = R × K × LS × C × P.
1. **A** is the average annual soil loss.
2. **R (Rainfall and Runoff Factor)**: Represents the erosivity of rainfall.
3. **K (Soil Erodibility Factor)**: This is the 'Soil erodibility index'. It represents the inherent susceptibility of soil particles to detachment and transport by runoff. It depends on soil texture, structure, organic matter, and permeability.
4. **LS (Slope Length and Steepness Factor)**: Represents the effect of topography (Option b).
5. **C (Cover and Management Factor)**: Represents the effect of cropping and management practices (Option a).
6. **P (Support Practice Factor)**: Represents the ratio of soil loss with a specific erosion control measure to the loss with contour farming (Option c).
Therefore, the K factor specifically refers to the Soil erodibility index.
Seed ___________ is a pre sowing hydration treatment of seeds for rapid and uniform emergence, germination and growth.
A)
prinching
B)
blending
C)
vigour test
D)
priming
Seed priming is a specialized pre-sowing technique where seeds are hydrated to a level that allows metabolic activities to begin (initiating the first stage of germination) but stops just before the radical emerges (protrusion). This 'pre-activation' ensures that once the seeds are sown in the field, they germinate more rapidly and uniformly, even under suboptimal environmental conditions.
Analysis of other options:
- a. prinching: This is not a recognized term in seed technology.
- b. blending: This refers to mixing different lots of seeds to achieve a specific quality or variety, not a hydration treatment.
- c. vigour test: This is a diagnostic procedure used to evaluate the potential of a seed lot to emerge under stress; it is a test of quality, not a treatment for improvement.
Orobanche is a:
A)
Shoot parasite
B)
Root parasite
C)
Stem parasite
D)
Flower parasite
Orobanche, commonly known as broomrape, is a genus of parasitic plants. It is characterized as a holoparasite, meaning it lacks chlorophyll and cannot perform photosynthesis, relying entirely on its host for water and nutrients. It achieves this by attaching itself to the roots of host plants (such as legumes, solanaceous crops, and tobacco) using a specialized organ called the haustorium.
Analysis of options:
- a. Shoot parasite: Incorrect. Shoot parasites (like Dodder/Cuscuta) attach to the stems or leaves of the host.
- b. Root parasite: Correct. Orobanche attaches specifically to the root system of the host plant.
- c. Stem parasite: Incorrect. This is synonymous with shoot parasites in this context.
- d. Flower parasite: Incorrect. There are no known plants that act as parasites specifically on flowers.
In India, Nitrogen is considered deficient, if soil contain less than ___________ kg per ha.
A)
180
B)
200
C)
280
D)
560
In the context of soil fertility and nutrient management in India, soil nitrogen (N) levels are typically categorized based on the total nitrogen content per hectare. According to standard agricultural guidelines used for soil testing and nutrient recommendation in India:
1. Low (Deficient): Less than 280 kg N/ha.
2. Medium: 280 to 560 kg N/ha.
3. High: More than 560 kg N/ha.
Therefore, if the soil contains less than 280 kg of Nitrogen per hectare, it is considered deficient. Option (d) 560 represents the threshold for 'High' nitrogen levels, while options (a) and (b) are not the standard benchmark values used for the deficiency threshold in general Indian soil classification systems.
Echinochloa crusgalli is a common weed of:
A)
Soybean
B)
Rice
C)
Mustard
D)
Maize
Echinochloa crus-galli, commonly known as Barnyard grass, is one of the most problematic and widespread weed species found in rice (Oryza sativa) cultivation globally. It is particularly damaging because it is a 'mimic weed'; its morphology (leaf shape and growth habit) is very similar to the rice plant, making manual weeding difficult. It competes aggressively with rice for nutrients, water, and sunlight. While it can occasionally be found in other grass-based crops or moist areas, it is specifically categorized as a primary weed of rice in agricultural science and weed management studies. Options a (Soybean), c (Mustard), and d (Maize) are not the primary hosts for this specific weed species compared to the high prevalence and impact seen in rice fields.
Pendimethalin is a common pre emergence herbicide used in:
A)
Rice
B)
Wheat
C)
Maize
D)
Mustard
Pendimethalin is a dinitroaniline herbicide used primarily as a pre-emergence herbicide to control annual grasses and certain broadleaf weeds.
1. **Why Maize (c) is correct**: Pendimethalin is widely recommended and used in maize (corn) cultivation because maize has a high tolerance to this chemical when applied pre-emergence, whereas the target weeds are suppressed during their germination phase.
2. **Why Rice (a) is incorrect**: Rice is typically grown in puddled/flooded conditions. Pendimethalin is not suitable for transplanted rice or flooded paddy fields as it is not designed for those specific aquatic/semi-aquatic environments; herbicides like Pretilachlor or Butachlor are more common here.
3. **Why Wheat (b) is incorrect**: While Pendimethalin can be used in some cereal crops, it is not the primary or most common choice for wheat compared to its extensive use in maize and soy; wheat often utilizes herbicides like Clodinafop or Sulfosulfuron.
4. **Why Mustard (d) is incorrect**: While it can be used in some oilseeds, it is not the 'common' or defining application compared to its standard use in maize.
A silicate clay enriched horizon formed by illuviation of clay.
A)
Umbric horizon
B)
Argillic horizon
C)
Oxic horizon
D)
Agric horizon
In soil morphology and taxonomy (specifically the USDA Soil Taxonomy), an Argillic horizon is a subsurface horizon characterized by the accumulation of silicate clays that have moved from the upper horizons (eluviation) and deposited in the lower horizon (illuviation). This process is known as lessivage.
Here is why the other options are incorrect:
- a. Umbric horizon: This is a surface horizon that is dark in color, thick, and has low base saturation (acidic), typically found in cool, moist climates. It is not defined by clay illuviation.
- c. Oxic horizon: This is a horizon characterized by extreme weathering, where most silicate clays have been removed or transformed into iron and aluminum oxides (common in tropical soils like Oxisols). It represents a loss of silicate clays rather than an accumulation.
- d. Agric horizon: This is a surface horizon that has been modified by human activity (e.g., plowing, fertilization), often characterized by an increase in organic matter due to agricultural practices.
Largest area under organic farming in India.
A)
Madhya Pradesh
B)
Assam
C)
Sikkim
D)
Uttarakhand
To solve this question, it is critical to distinguish between the 'first fully organic state' and the 'state with the largest area under organic farming.'
1. **Madhya Pradesh (Correct):** According to data from the APEDA (Agricultural and Processed Food Products Export Development Authority) and the Ministry of Agriculture, Madhya Pradesh consistently holds the largest total area under organic certification in India. This is due to its vast landmass and large-scale adoption of organic practices in various crops.
2. **Sikkim (Incorrect):** Sikkim is famous for being India's first '100% Organic State' (certified by the UN). While it is the most intensive in terms of percentage of land, its total geographical area is very small compared to Madhya Pradesh, meaning its total organic acreage is much lower.
3. **Assam and Uttarakhand (Incorrect):** While these states have significant organic farming initiatives and high potential due to their ecology, they do not lead the country in terms of total land area under organic certification.
Therefore, while Sikkim is the leader in 'organic status,' Madhya Pradesh is the leader in 'organic area.'
Insect Dactylopius tomentosus is used as biological control of weeds for eradication of:
A)
Johnson grass
B)
Congress grass
C)
Prickly pear
D)
Lantana camara
Dactylopius tomentosus, commonly known as the Cochineal insect, is a scale insect used globally as a highly effective biological control agent for the eradication of the Prickly Pear cactus (Opuntia spp.). The insect feeds on the sap of the cactus, causing systemic damage, weakening the plant, and eventually leading to its death. This is one of the most famous historical examples of successful biological control in agriculture.
Regarding the other options:
- Johnson grass (Sorghum halepense) is typically managed through herbicides or cultural practices.
- Congress grass (Parthenium hysterophorus) is biologically controlled by the leaf-feeding beetle Zygogramma bicolor.
- Lantana camara is managed using various biological agents, including the lace bug (Teleonideus scutellaris), but not Dactylopius tomentosus.
North eastern states comes under ___________ agro climatic zone.
A)
Eastern plateau and hill region
B)
Eastern Himalayan region
C)
North eastern Region
D)
Western Himalayan region
According to the Planning Commission of India, India is divided into 15 Agro-Climatic Zones (ACZs) based on physiological and climatic factors. The North Eastern states (including Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura) fall under the 'Eastern Himalayan Region' (Zone 11). This zone is characterized by high rainfall, hilly terrain, and a humid subtropical to alpine climate.
Analysis of other options:
- Option (a) Eastern plateau and hill region: This refers to zones covering parts of Chhattisgarh, Jharkhand, and Odisha.
- Option (c) North eastern Region: While geographically correct, this is not the official nomenclature used for the 15 Agro-Climatic Zones of India.
- Option (d) Western Himalayan region: This covers Jammu & Kashmir, Himachal Pradesh, and Uttarakhand.
Micro nutrient elements are:
A)
Ni and K
B)
N and Cu
C)
Zn and S
D)
Ni and Zn
Plant nutrients are categorized into macronutrients (required in large quantities) and micronutrients (required in trace amounts).
1. Macronutrients include: Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), and Sulfur (S).
2. Micronutrients include: Iron (Fe), Manganese (Mn), Copper (Cu), Molybdenum (Mo), Zinc (Zn), Boron (B), Chlorine (Cl), and Nickel (Ni).
Evaluating the options:
- Option (a): Ni is a micronutrient, but K (Potassium) is a macronutrient.
- Option (b): Cu is a micronutrient, but N (Nitrogen) is a macronutrient.
- Option (c): Zn is a micronutrient, but S (Sulfur) is a macronutrient.
- Option (d): Both Ni (Nickel) and Zn (Zinc) are classified as micronutrients.
Therefore, option (d) is the only pair consisting exclusively of micronutrients.
Zea mays saccharata belongs to:
A)
Sweet corn
B)
Flint corn
C)
Pop corn
D)
Dent corn
The scientific name 'Zea mays saccharata' refers to a specific variety of maize. The species name 'saccharata' is derived from the Latin word 'saccharum', meaning sugar. This variety is characterized by a genetic mutation that prevents the conversion of sugar into starch in the kernels, resulting in a higher sugar content and a sweeter taste compared to field corn.
Breakdown of other options:
- Flint corn (Zea mays indurata): Characterized by a hard outer shell of starch.
- Pop corn (Zea mays everta): Characterized by a thick hull and a small amount of moisture inside that expands when heated.
- Dent corn (Zea mays indentata): The most common field corn, characterized by a 'dent' at the top of the kernel as it dries.
The Mizoram Organic Farming Bill/Act was passed in the year.
A)
2004
B)
2000
C)
2015
D)
2010
The Mizoram Organic Farming Act was enacted in 2010. The state government of Mizoram introduced this legislation to promote organic farming practices, regulate the production and certification of organic products, and transition the state towards a sustainable agricultural model. This act provides the legal framework for the certification of organic produce and the establishment of organic farming standards within the state. Options a (2004), b (2000), and c (2015) are incorrect as they do not correspond to the year the specific Organic Farming Act was passed by the Mizoram Legislative Assembly.
Foundation seed is labelled in ___________ colour.
A)
White
B)
Blue
C)
Green
D)
Golden yellow
In seed technology, seed classes are identified by specific colors of tags attached to the seed bags to ensure quality control and traceability. The standard color coding is as follows:
1. Nucleus Seed: No tag (or sometimes a yellow tag in specific contexts, but generally not tagged in the same way as certified classes).
2. Breeder Seed: Golden Yellow tag.
3. Foundation Seed: White tag.
4. Registered Seed: Purple tag.
5. Certified Seed: Azure Blue tag.
Therefore, Foundation seed is labeled with a white tag. Option (b) Blue is for Certified seed, (c) Green is not a standard seed class tag color, and (d) Golden yellow is for Breeder seed.
The final product of nitrification.
A)
NO
B)
NO2
C)
NH
D)
Elemental N
Nitrification is a two-step biological process in the nitrogen cycle where ammonia is oxidized to nitrate.
Step 1: Ammonia (NH3/NH4+) is oxidized to Nitrite (NO2-) primarily by bacteria such as Nitrosomonas.
Step 2: Nitrite (NO2-) is further oxidized to Nitrate (NO3-) primarily by bacteria such as Nitrobacter.
Analyzing the options provided:
- Option (a) NO (Nitric oxide) is a product of denitrification, not nitrification.
- Option (b) NO2 (Nitrite) is an intermediate product. However, looking at the provided options, NO3 (Nitrate) is missing. In many exam contexts where NO3 is absent but NO2 is present, NO2 is the closest chemical species related to the nitrification pathway provided, although technically Nitrate (NO3-) is the final stable product. Given the choices, NO2 represents the oxidized nitrogen species resulting from the process.
- Option (c) NH (Imidogen) is not a standard product of this cycle.
- Option (d) Elemental N (N2) is the final product of denitrification, not nitrification.
Note: While the scientifically accurate final product is Nitrate (NO3-), among the given choices, NO2 is the only one that is a direct product of the nitrification sequence.
Under the land capability classes, Class II is denoted by:
A)
Red
B)
Green
C)
Yellow
D)
Black
In the Land Capability Classification (LCC) system, land is categorized into eight classes (I to VIII) based on its suitability for cultivation and the limitations present. To make these maps easily readable, a standardized color-coding system is used.
1. Class I: Denoted by Light Green (Very good land, few limitations).
2. Class II: Denoted by Yellow (Good land, some limitations).
3. Class III: Denoted by Dark Yellow or Orange (Moderately good land).
4. Class IV: Denoted by Red (Fairly good land, severe limitations).
5. Class V to VIII: Usually denoted by various shades of brown, grey, or blue depending on the specific mapping standard used for non-arable or forest lands.
Therefore, Class II land, which has slight limitations that can be overcome by simple conservation practices, is represented by the color Yellow.
___________ is the practice of growing protective crops and row crops in alternative strips on the contours.
A)
Strip cropping
B)
Contour cropping
C)
Selective cropping
D)
Relay cropping
Step-by-step reasoning:
1. **Definition of Strip Cropping**: Strip cropping is a soil conservation method where different crops are grown in alternating strips. Typically, a 'row crop' (like corn or sorghum), which leaves the soil bare and prone to erosion, is alternated with a 'protective crop' (like clover, grass, or legumes), which provides dense ground cover to trap soil and slow down runoff.
2. **Application on Contours**: To maximize effectiveness in preventing soil erosion on slopes, these strips are planted across the slope following the contour lines (contour strip cropping).
3. **Evaluating other options**:
- **Contour cropping (b)**: This is the general practice of plowing and planting across the slope. While strip cropping often uses contours, contour cropping refers to the general alignment, not specifically the alternation of protective and row crops.
- **Selective cropping (c)**: This is not a standard technical term for a soil conservation practice involving alternating strips.
- **Relay cropping (d)**: This is a method where a second crop is planted into an existing standing crop before the first one is harvested. It relates to time/seasoning rather than spatial strips for erosion control.
Soybean seed contain ___________ % protein.
A)
15
B)
30
C)
20
D)
40
Soybean (Glycine max) is renowned as one of the richest plant-based sources of protein. On average, soybean seeds contain approximately 36% to 45% protein by dry weight. Among the given options, 40% is the most accurate representation of the typical protein content found in soybean seeds.
Breakdown of options:
- Option (a) 15%: This is too low; typical of some cereals or low-protein legumes.
- Option (b) 30%: While some varieties may fall near this range, it is below the standard average for high-quality soybeans.
- Option (c) 20%: This is characteristic of many other pulses (like peas or lentils) but is significantly lower than soybean protein levels.
- Option (d) 40%: This aligns with the established scientific data for soybean protein content (typically cited as ~40%).
___________ makes the seed more uniform in size, weight and shape.
A)
Pelleting
B)
Priming
C)
Roughing
D)
Blenching
Pelleting is a seed treatment process where seeds (especially very small or irregularly shaped ones) are coated with inert materials (like clay, talc, or lime) and binders to create a uniform, spherical shape. This process makes the seeds more uniform in size, weight, and shape, which is critical for precision planting using mechanical seed drills, as it ensures accurate seed spacing and depth.
Why other options are incorrect:
- b. Priming: This is a pre-sowing treatment involving controlled hydration of seeds to synchronize and accelerate germination; it does not change the physical size or shape of the seed.
- c. Roughing: This is the process of identifying and removing 'off-types' or diseased plants from a seed production field to maintain genetic purity.
- d. Blenching: This is not a standard term in seed technology; it is typically associated with food processing (blanching) or whitening of materials.
___________ is allowed to be used in organic farming.
A)
Urea
B)
Rock phosphate
C)
NPK
D)
DAP
Organic farming prohibits the use of synthetic, chemically manufactured fertilizers.
1. **Urea (a)**: This is a synthetic nitrogen fertilizer produced via the Haber-Bosch process. It is strictly prohibited in organic farming.
2. **Rock phosphate (b)**: This is a naturally occurring mineral phosphate (phosphorite). Because it is a raw, minimally processed mineral rather than a chemically synthesized compound, it is generally permitted in organic farming to supplement phosphorus levels, provided it does not contain prohibited additives.
3. **NPK (c)**: This refers to synthetic compound fertilizers containing Nitrogen, Phosphorus, and Potassium. These are manufactured chemicals and are not allowed.
4. **DAP (d)**: Di-ammonium Phosphate is a highly soluble synthetic fertilizer produced by reacting ammonia with phosphoric acid. It is prohibited in organic farming.
Therefore, Rock phosphate is the only naturally derived mineral among the options that is acceptable under organic certification standards (such as IFOAM or NPOP).
Sunflower is a native of:
A)
USA
B)
Spain
C)
India
D)
Africa
The sunflower (Helianthus annuus) is native to North America, specifically the central region of the United States and Mexico. It was domesticated by Native Americans long before it was introduced to Europe and Asia.
- Option (a) USA: Correct, as the plant originates from the North American continent.
- Option (b) Spain: Incorrect. While Spanish explorers are credited with bringing the sunflower from the Americas to Europe in the 16th century, it is not native to Spain.
- Option (c) India: Incorrect. Sunflower was introduced to India much later for commercial oil production.
- Option (d) Africa: Incorrect. The plant does not originate from the African continent.
Low pressure area near the equator are called:
A)
Equinox
B)
Polar calms
C)
Burst
D)
Doldrums
The correct answer is 'Doldrums'. In climatology, the Doldrums refer to the Intertropical Convergence Zone (ITCZ), a belt of low pressure circling the Earth near the equator. In this region, the trade winds from the Northern and Southern Hemispheres meet. Because the intense solar heating causes air to rise vertically rather than flow horizontally, there is very little surface wind, leading to the characteristic 'calms' associated with this area.
Why other options are incorrect:
- a. Equinox: This is an astronomical event occurring twice a year when the sun is exactly above the equator, making day and night of equal length; it is not a pressure system.
- b. Polar calms: While there are areas of low wind in polar regions, the specific term for the equatorial low-pressure belt is the Doldrums.
- c. Burst: In meteorology, a 'burst' (such as a monsoon burst) refers to a sudden increase in rainfall or wind intensity, not a permanent pressure zone.
According to USDA soil texture classification, silt is ___________ mm.
A)
0.05 to 0.1
B)
0.002 to 0.02
C)
< 0.002
D)
0.002 to 0.05
According to the USDA (United States Department of Agriculture) soil texture classification system, soil separates are categorized based on their particle diameter as follows:
1. **Sand**: Particles with a diameter between 0.05 mm and 2.0 mm.
2. **Silt**: Particles with a diameter between 0.002 mm and 0.05 mm.
3. **Clay**: Particles with a diameter less than 0.002 mm.
Analyzing the options:
- Option (a) 0.05 to 0.1 mm falls within the range of sand.
- Option (b) 0.002 to 0.02 mm is a subset of the silt range but does not represent the full classification boundary.
- Option (c) < 0.002 mm defines clay particles.
- Option (d) 0.002 to 0.05 mm exactly matches the USDA definition for silt.
___________ fertilizer is given as top dressing
A)
P
B)
N
C)
S
D)
K
Top dressing is the application of fertilizer to the soil surface around the plants after they have been established. Nitrogen (N) is the primary nutrient applied as a top dressing because it is highly mobile in the soil and prone to leaching (washing away with water). To ensure the plant has access to nitrogen during its peak growth stages and to prevent loss, it is applied in split doses on the surface. In contrast, Phosphorus (P) and Potassium (K) are relatively immobile in the soil and are typically applied as basal dressings (incorporated into the soil before or during planting) to ensure they are available near the root zone throughout the crop cycle. Sulfur (S) is also generally applied as a basal dose or through specific soil amendments.
Acidic soils are generally deficient in:
A)
P
B)
Fe
C)
Cu
D)
Al
Soil pH significantly influences the availability of essential plant nutrients. In acidic soils (typically pH < 5.5), the availability of Phosphorus (P) decreases sharply. This happens because phosphorus reacts with soluble aluminum (Al) and iron (Fe) to form insoluble compounds (aluminum phosphates and iron phosphates), a process known as 'phosphorus fixation.' Consequently, P becomes unavailable for plant uptake, making acidic soils generally deficient in P.
Regarding the other options:
- b. Fe (Iron) and c. Cu (Copper): These micronutrients become more soluble and more available as soil pH decreases. In very acidic soils, they can even reach toxic levels.
- d. Al (Aluminum): Aluminum is not a nutrient but a metal that becomes highly soluble and toxic to plants in acidic soils. It is present in abundance (available form) in acidic soils, not deficient.