Air-to-Water Condensation Farming and Fogponics for "Zero-Watering" Horticulture in India: A Review of Technologies, Crop Suitability and Readiness for El Niño-Driven Water Scarcity

India produced an estimated 369.05 million tonnes of horticultural produce from 29.48 million ha in 2024–25. Its per-capita water availability, however, has fallen to about 1,486 m³ (2021) and is projected to reach 1,367 m³ by 2031, below the 1,700 m³ water-stress threshold. Greenhouse warming is expected to strengthen the inverse El Niño–monsoon relationship. Future El Niño years may therefore cause crop-yield losses about 30% larger than those observed historically, and nearly 200 Indian districts have been identified as highly vulnerable in 2026. This review examines two complementary pathways that decouple high-value horticulture from rainfall and groundwater: (i) air-to-water condensation farming, in which atmospheric water generators (AWGs), sorbent-based harvesters, dew condensers or fog collectors, preferably solar-powered, supply condensate to the root zone of sheltered crops; and (ii) fogponics, an aeroponic variant that delivers nutrient solution as a 5–30 µm fog to suspended roots. Published evidence shows that solar-driven atmospheric water can irrigate leafy vegetables with growth comparable to tap water, that fog collectors can yield 2.9–3.3 L m⁻² day⁻¹ (annual mean) at favourable coastal sites, and that aeroponic seed-potato systems are commercially established in India. Specific energy demand nevertheless ranges from about 0.02 kWh L⁻¹ in humid air to 3.64 kWh L⁻¹ in very dry air, and levelized water costs of US$ 0.09–0.40 L⁻¹ have been reported. These figures confine the approach, at present, to high-value, small-footprint protected cultivation, nurseries and propagation. A crop-suitability matrix for Indian fruits, vegetables and flowers, an agro-climatic zoning framework, a sizing procedure and a research roadmap are proposed. "Zero watering" is best understood as zero dependence on irrigation from surface or groundwater, not zero water input. The technology can serve as climate-insurance infrastructure for nurseries and protected horticulture during El Niño years.