Specialist (Soil Science/Soil conservation) 2019 — Kerala PSC PYQ Practice with Answers

Correct answer (Option A):\nSodium Adsorption Ratio (SAR) is a widely accepted irrigation water quality parameter used to express the sodicity hazard. It quantifies the relative proportion of sodium (Na⁺) ions to calcium (Ca²⁺) and magnesium (Mg²⁺) ions in the water, indicating the risk of soil structure dispersion and permeability reduction.\n\nWhy others are wrong:\nOption B refers to concentration alone without assessing balancing divalent cations. Options C and D measure general salinity risks rather than specific structural hazards caused by excessive sodium ions.\n\nStudy tip:\nThe standard formula used to compute this parameter is SAR = Na⁺ / √((Ca²⁺ + Mg²⁺) / 2), where ion concentrations are in meq/L.

Correct answer (Option D):\nSagara is an improved, high-yielding rice variety developed and released by Kerala Agricultural University (KAU) to boost regional paddy productivity. It exhibits good agronomic traits suited to local soil types and climate conditions.\n\nWhy others are wrong:\nOptions A, B, and C represent completely different crop families that are unrelated to the regional field trials associated with the specific pedigree of Sagara.\n\nRemember:\nKAU has released several landmark high-yielding rice strains tailored specifically for different unique ecological tracts in Kerala such as Kuttanad and Pokkali.

Correct answer (Option B):\nThe standard recommended primary fertilizer package for an adult coconut palm under regular average management practices is 0.34 kg Nitrogen (N), 0.17 kg Phosphorus (P₂O₅), and 0.68 kg Potassium (K₂O) per palm per year.\n\nWhy others are wrong:\nOptions A, C, and D are corrupted options containing names of other crops due to a standard text formatting artifact in the original public database documents.\n\nRemember:\nApplying primary nutrients in this exact specific ratio helps optimize nut yields, copra quality, and build general resistance against endemic vascular and leaf diseases.

Correct answer (Option C):\nApomixis is a specialized form of asexual reproduction in plants where functional seeds are generated entirely without the fusion of male and female gametes. This pathway allows the maternal plant to bypass normal meiotic reduction and syngamy, producing clonal offspring.\n\nWhy others are wrong:\nOption B describes standard amphimixis (sexual reproduction). Options A and D represent specialized mechanical methods of macro-vegetative plant propagation.\n\nStudy tip:\nApomixis is highly valued in modern agricultural biotechnology and plant breeding because it fixes hybrid vigor indefinitely across successive seed generations.

Correct answer (Option A):\nCleistogamy refers to self-pollination that occurs within a flower that remains permanently closed and un-opened. This mechanism guarantees successful seed set in stressful or isolated environments because the reproductive organs are entirely shielded from external elements.\n\nWhy others are wrong:\nOption B is an evolutionary strategy where female organs mature before male organs to avoid selfing. Option C is cross-pollination. Option D is self-pollination occurring within standard open flowers.\n\nRemember:\nCommon examples of plants exhibiting cleistogamy include Commelina benghalensis, certain varieties of violets, and arachis hypogaea (groundnut).