Prosopis cineraria (Khejri) is the most valuable indigenous fodder tree across the Thar Desert of India:
Its lopped leaves (locally called loong) are rich in crude protein (14–18%), calcium, and digestible nutrients, serving as the staple survival fodder for camels, sheep, goats, and cattle during the dry winter and summer months when ground grasses vanish.

Hippophae rhamnoides (Sea buckthorn, family Elaeagnaceae) is a non-leguminous actinorhizal shrub of the cold arid Trans-Himalayas (Ladakh, Lahaul-Spiti):
It forms root nodules in symbiotic association with the nitrogen-fixing actinomycete Frankia.
Actinorhizal plants like Hippophae, Casuarina, and Alnus fix large quantities of nitrogen via Frankia, allowing them to colonize severely degraded, nutrient-poor gravels and scree slopes.

Detailed analysis of options:

• Rhizobium: Forms symbiotic root nodules with leguminous trees (e.g., Acacia, Dalbergia, Leucaena).
• Frankia: An actinomycete (filamentous nitrogen-fixing bacterium) that forms actinorhizal root nodules in non-leguminous woody plants such as Casuarina equisetifolia, Alnus nepalensis, and Hippophae rhamnoides.
• Azotobacter: Free-living, non-symbiotic aerobic nitrogen fixer in soil.
• Bacillus: Common heterotrophic soil bacterium, some species solubilize phosphorus.