Free Soil Science MCQs with Answers

• A. R, K, S, L, C and P
• B. R and K
• C. R, K, S and L
• D. R, K and S

Explanation: The complete USLE is A = RKL SCP, where R is rainfall erosivity, K soil erodibility, L slope length, S slope steepness, C cover-management…

• A. Infiltration
• B. Percolation
• C. Leaching
• D. hydraulic conductivity

Explanation: Percolation is the downward movement of water through the soil profile or a soil column.

• A. Mg
• B. Mo
• C. Ca
• D. Cu

Explanation: Sodic soils contain excess exchangeable sodium, which can displace calcium and produce a relative calcium deficiency.

• A. 46%
• B. 36%
• C. None of the above
• D. 76%

Explanation: Common estimates place the area of Pakistan affected by wind and water erosion at about 76% of the country’s total area.

• A. Thal, Cholistan
• B. All of the above
• C. Tharparkar & vast areas of Balochistan
• D. Parts of Mianwali and D.G

Explanation: Wind erosion is prominent in the sandy Thal and Cholistan regions, parts of Mianwali and Dera Ghazi Khan, Tharparkar, and extensive areas…

• A. Peshawar series
• B. Gujranwala series
• C. All of the above
• D. wazirabad & pindorian series

Explanation: Prismatic structure is associated with several Pakistani soil series, including Peshawar, Gujranwala, Wazirabad and Pindorian.

• A. Massive
• B. Aggregated
• C. Single-grained
• D. All of the above

Explanation: In single-grained soil structure, sand, silt or gravel particles remain separate and do not form aggregates.

• A. None of theseAgriculture & Forestry
• B. Atom analyser solution
• C. Asia agriculture society
• D. Atomic absorption spectrophotometer

Explanation: AAS means atomic absorption spectrophotometer, an instrument used to measure elements by detecting the absorption of light by their atoms.

• A. metamorphic rocks
• B. Sedimentary rocks
• C. Igneous rocks
• D. Shales

Explanation: Sedimentary rocks are the most widespread rocks at the Earth's surface because weathering products are deposited and compacted into…

• A. Sedimentary Rocks
• B. Stratified rocks
• C. None of the above
• D. Aqueous rocks

Explanation: Granite and basalt form when molten material cools and solidifies, so both are igneous rocks.

• A. Geo chemical weathering
• B. Judo weathering
• C. Pedo chemical weathering
• D. both a and c

Explanation: Weathering in soil science may be described as geochemical weathering in the parent material and pedochemical weathering during soil…

• A. Both a and c
• B. solonchalk soil
• C. Muck soil
• D. Peat soil

Explanation: Organic soils contain more than about 20% organic matter and are broadly called peat or muck soils.

• A. 3 %
• B. less than 10 %
• C. less than 1 %
• D. 5%

Explanation: Organic matter in most Pakistani agricultural soils is generally below 1%, largely because of high temperatures, rapid decomposition and…

• A. None of these
• B. NH2-CO-NH-CO-NH2
• C. (NH4)2CO3
• D. CO (NH2)2

Explanation: Urea is CO(NH₂)₂, also written as NH₂CONH₂, containing one carbonyl group bonded to two amino groups.

• A. Vermiculite
• B. Illite
• C. Montmorillonitic
• D. Amorphous clay

Explanation: Vermiculite has expandable interlayers that can trap potassium ions, giving it the greatest potassium-fixation capacity among the listed…

• A. 7.0-7.5
• B. 8.0-8.5
• C. 8.5-9.0
• D. 6.5-7.5

Explanation: Calcareous soils are alkaline because calcium carbonate buffers their reaction, commonly keeping pH around 8.0 to 8.5.

• A. NaHCO3
• B. Na2CO3
• C. MgSO4
• D. Both a & b

Explanation: Alkali soils commonly contain soluble sodium carbonates, especially sodium carbonate and sodium bicarbonate, which create high alkalinity…

• A. Soil Algae
• B. Soil Fungi
• C. Soil Bacteria
• D. None of these

Explanation: Diatoms are microscopic algae with silica-rich cell walls, and they may occur among soil algae. They are not fungi or bacteria.

• A. Fe2 (NO3)3
• B. Fe (NO3)3
• C. Fe3 (NO2)
• D. None of these

Explanation: In Fe(NO3)3, each nitrate ion has a -1 charge and three nitrates total -3, so iron must be Fe3+, or trivalent.

• A. Capillary water
• B. Hygroscopic water
• C. Gravitational water
• D. None of the above

Explanation: Water filling large soil pores and draining downward under gravity is gravitational water.