UPHESC Assistant Professor Agricultural Chemistry & Soil Science PYQs

Concept: Soil resilience (Lal, Szabolcs) is the ability of a soil to recover its functional and structural integrity after a disturbance.

1. Soil resistance is the ability to withstand change during the disturbance itself.
2. Soil quality is the capacity to function; soil productivity is the capacity to produce crops.

Short trick: Resist = not bend; Resilience = bounce back.

Concept: Humic and fulvic acids and other organic ligands form chelates (ring complexes) with Zn, Cu, Fe and Mn.

1. Chelation keeps the metals in a protected form that resists leaching and precipitation while still being available to roots.
2. Fixation reduces availability rather than conserving the nutrient in an available form.

Short trick: Chelate = 'claw' that holds the metal.

Concept: Glomalin is a sticky glycoprotein produced by arbuscular mycorrhizal fungi (Glomus).

1. Residue addition and reduced tillage favour AM fungi, so glomalin-related soil protein rises.
2. Glomalin glues micro-aggregates into water-stable macro-aggregates (>250 µm).

Short trick: Glomalin = 'super glue' of soil (from Glomus).

Concept: The Soil Health Card scheme was launched by the Prime Minister on 19 February 2015 at Suratgarh (Sri Ganganagar, Rajasthan).

1. Cards report 12 parameters (N, P, K, S, Zn, Fe, Cu, Mn, B, pH, EC, OC) with fertilizer recommendations, renewed every 2 years.
2. 5 December is World Soil Day; 19 February is observed as Soil Health Card Day.

Short trick: Suratgarh, 19-02-2015.

Concept: NBSS&LUP (Sehgal et al., 1990–92) divided India into 20 agro-ecological regions (AERs).

1. These were further divided into 60 agro-ecological sub-regions (AESRs) using soils, climate (length of growing period) and physiography.
2. The Planning Commission separately recognised 15 agro-climatic zones.

Short trick: 20 regions, 60 sub-regions (NBSS&LUP); 15 agro-climatic zones.

Concept: Watersheds are classified by size.

1. Macro > 50,000 ha; sub-watershed 10,000–50,000 ha; milli-watershed 1,000–10,000 ha; micro-watershed 100–1,000 ha; mini-watershed 1–100 ha.

Short trick: Milli = 1,000s of ha; Micro = 100s; Mini = below 100.

Concept: In the land capability classification (USDA, as adopted in India):

1. Class II has moderate and Class III severe limitations.
2. Class IV has very severe limitations: steep slopes, severe erosion (past or hazard), poor drainage, shallow soil. It can be cultivated only occasionally with intensive conservation.
3. Class V is nearly level, not erosion-prone, but too wet or stony for cultivation.

Short trick: Severe erosion + poor drainage = last arable class = IV.

Concept: Slope limits commonly used with land capability classes:

1. Class I: 0–1%; Class II: 1–3%; Class III: 3–8%; Class IV: 8–15%; Class VI: 15–35%; Class VII: 35–50%; Class VIII: >50%.
2. So Class IV has 8–15% slope.

Short trick: 1-3-8-15-35: classes II, III, IV, VI in order.

Concept: Land capability classes rest on permanent limitations: erosion (e), wetness or inundation (w), soil limitations such as salinity, depth and stoniness (s), and climate (c).

1. Saline, inundated and organic soils are placed in classes with s or w subclasses.
2. Low fertility is a correctable limitation (fertilizers and manures), so it is not a basis for capability classes.

Short trick: Correctable by fertilizer = ignored in LCC.

Concept: Watershed management as a national programme took shape in the Seventh Five Year Plan (1985–90).

1. NWDPRA (National Watershed Development Project for Rainfed Areas) was conceived in the Seventh Plan and launched in 1990–91.
2. Earlier schemes (soil conservation in river valley catchments 1962, DPAP 1973, DDP 1977) were area programmes, not a watershed programme as such.

Short trick: 7th Plan, then NWDPRA.