Question

The major drawbacks of conventional tillage are categorized as:

(A) Decrease of soil organic matter
(B) Decrease of soil moisture
(C) Short-term potential for soil compaction
(D) Adversely affect the soil structure

Choose the correct answer from the options given below:

• A. (A), (B) and (C) only.
• B. (B), (C) and (D) only.
• C. (A), (B) and (D) only.
• D. (A), (B), (C) and (D).

Hint:

Check each statement against known effects of conventional tillage, paying close attention to whether compaction is described as a short-term or long-term effect.

Answer 1

The Correct Option is C

Step 1: Check statement (A). Repeated conventional tillage (ploughing, harrowing) exposes buried organic matter to air, speeding up oxidation and microbial breakdown of humus, so soil organic matter does go down over time. (A) is a genuine drawback.

Step 2: Check statement (B). Turning and pulverizing the soil surface increases evaporation and exposes moist soil to sun and wind, so conventional tillage does reduce soil moisture conservation compared to no-till or minimum-till systems. (B) is a genuine drawback.

Step 3: Check statement (C). Conventional tillage does cause soil compaction below the tilled layer, because implements are repeatedly run at the same shallow depth, forming a compacted plough pan. This compaction problem builds up gradually with each season and is described in soil management literature as a long-term effect, not a short-term one. Since the statement specifically claims a "short-term" potential, it does not match the accepted description, so (C) as worded is not a correct drawback.

Step 4: Check statement (D). By breaking down natural soil aggregates and disturbing pore continuity season after season, conventional tillage does adversely affect overall soil structure in the long run. (D) is a genuine drawback.

Step 5: Only (A), (B) and (D) hold as correctly described drawbacks, while (C) is wrong because compaction from conventional tillage is a long-term issue, not a short-term one. So option 3 is correct, and options 1, 2 and 4, which all include (C), are incorrect.