UPHESC Assistant Professor Agronomy PYQs

Concept: Probability lies between 0 (impossible event) and 1 (certain event).

1. −1 to +1 is the range of the correlation coefficient.
2. Probability can never be negative.

Short trick: Probability 0→1; correlation −1→+1.

Concept: Mode is the value that occurs most often (repeatedly) in the data.

1. Mean – arithmetic average; Median – middle value of ordered data.
2. Mode can be read from the highest point of the frequency curve.

Short trick: Mode = 'most often' (fashion).

Concept: Latin Square Design controls variation in two directions by blocking along both rows and columns.

1. RBD – one-way gradient.
2. CRD – homogeneous material (lab/pot); Split plot – factors needing different plot sizes.

Short trick: Two gradients → Latin square (each treatment once in each row and column).

Concept: Fineness (micronaire, µg/inch): very fine < 3.0; fine 3.0–3.9; medium 4.0–4.9; slightly coarse 5.0–5.9; coarse ≥ 6.0.

1. Lower micronaire = finer fibre.
2. Very fine fibres are typical of long-staple G. barbadense types.

Short trick: Below 3 very fine, 3s fine, 4s medium, 5s slightly coarse, 6+ coarse.

Concept: M.Y. Nuttonson (1955), 'Wheat–climate relationships and the use of phenology in ascertaining the thermal and photo-thermal requirements of wheat', fixed the base temperature used for wheat heat units (growing degree days).

1. Base temperature for wheat ≈ 4.5 °C (≈ 40 °F) in this work; GDD = Σ(T_mean − T_base).
2. The other authors are not associated with the wheat base temperature.

Short trick: Nuttonson 1955 – wheat GDD base.

Concept: Soybean is a warm-season crop; optimum 26–30 °C; growth is badly hampered below about 10 °C (and above ~40 °C).

1. Germination is poor in cold soil.
2. 25–30 °C lie in the optimum range, so they are wrong.

Short trick: Soybean: below 10 °C stop, 26–30 °C best.

Concept: Organic farming rests on a living, biologically active soil ('feed the soil, not the plant'); IFOAM principles: health, ecology, fairness, care.

1. Agrochemicals are excluded.
2. Yield is not the only goal; all nutrients are supplied through organic sources and recycling.

Short trick: Organic = living soil.

Concept: Ley farming: growing grasses/legume forage (ley) for some years in rotation with arable crops.

1. It restores soil structure, organic matter and N.
2. Silviculture – raising forest trees; agroforestry – trees with crops.

Short trick: Ley = temporary grass/legume pasture in rotation.

Concept: Ideal agroforestry trees: fast growing, light/narrow crown, deep roots, coppicing ability, N-fixing, multipurpose.

1. Small crown lets light reach the intercrop.
2. Fast growth gives early returns (e.g. poplar, eucalyptus, Leucaena).

Short trick: Fast growth + less shade.

Concept: Timely sown irrigated wheat: N 120–150, P₂O₅ 40–60, K₂O 40 kg/ha (common recommendation 120:60:40).

1. Full P and K are applied basally at sowing.
2. Higher P (80+) is not recommended for normal soils.

Short trick: Wheat 120:60:40 – P up to 60.

Concept: Bunch (erect) groundnut: 30 cm between rows × 10 cm between plants (≈ 3.3 lakh plants/ha).

1. Spreading types: 45–60 × 10–15 cm.
2. Seed rate for bunch types ≈ 100 kg kernels/ha.

Short trick: Bunch 30 × 10; spreading 45–60 × 15.

Concept: Percolation depends on macropores; sandy soils have large pores and highest hydraulic conductivity.

1. Clay has many fine pores – slowest percolation.
2. Loam and alluvium are intermediate.

Short trick: Sand drains, clay holds.

Concept: Australia has the largest organic agricultural area in the world (about 35 million ha, mostly extensive grazing land) – FiBL/IFOAM surveys.

1. Argentina is second; India has the largest number of organic producers.
2. USA and Canada have much smaller areas.

Short trick: Area → Australia; Producers → India.

Concept: Moisture equivalent (Briggs & McLane): water retained by a 1 cm soil layer after centrifuging at 1000 × g; this force corresponds to a soil water potential of about −1 bar.

1. It approximates field capacity in medium/fine textured soils.
2. Field capacity −0.1 to −0.33 bar; wilting point −15 bar; hygroscopic coefficient −31 bar.

Short trick: Moisture equivalent: 1000 g → about −1 bar.

Concept: Hypoxia = partial deficiency of O₂ (early/short waterlogging); Anoxia = complete absence of O₂.

1. Acclimation – adjustment to stress.
2. Anoxemia – lack of O₂ in blood (animal term).

Short trick: Hypo = less; An = none.

Concept: Chickpea (desi, medium seeded) seed rate is 75–80 kg/ha at 30 × 10 cm spacing.

1. Bold-seeded kabuli types need 90–100 kg/ha; small-seeded 60–65 kg/ha.
2. Seed is treated with Rhizobium and Trichoderma before sowing.

Short trick: Gram ≈ 75–80 kg/ha, row 30 cm.

Concept: Water films around particles and in small pores are held by surface tension (cohesion) together with adhesion – the capillary forces.

1. Gravity removes water, it does not retain it.
2. Osmotic tension arises from solutes, not from films around particles.

Short trick: Thin film = surface tension + adhesion.

Concept: Standard moisture extraction pattern (40-30-20-10): of the water used by roots, 40% comes from the upper quarter of the root zone.

1. Next quarters supply 30%, 20% and 10%.
2. Hence irrigation is scheduled mainly on the upper root-zone moisture.

Short trick: 40-30-20-10 rule.

Concept: In acid soils Fe and Al fix applied P strongly; band placement concentrates the fertilizer in a narrow band, reducing soil contact and fixation.

1. It keeps P available near roots for longer.
2. Subsoil placement is used for acid subsoils of humid regions only with deep placement machinery; broadcast increases fixation.

Short trick: High fixing (acid) soils → band placement.

Concept: DAP (18-46-0) contains P in water-soluble (monocalcium-type ammonium phosphate) form.

1. Water soluble: SSP, TSP, DAP, MAP.
2. Citrate soluble: dicalcium phosphate, basic slag; Insoluble: rock phosphate, bone meal.

Short trick: DAP, SSP, TSP → water soluble; rock phosphate → insoluble.