Q1. Which of the following biofertilizers is specifically known for fixing atmospheric nitrogen in legume root nodules and is promoted under Rajasthan's "Aapno Khet–Aapni Khaad" campaign?
A Rhizobium Correct
B Trichoderma
C Pseudomonas fluorescens
D Mycorrhiza
Explanation
Rhizobium is a symbiotic nitrogen-fixing bacteria that forms nodules on legume roots and fixes atmospheric nitrogen into plant-available forms. It is one of the three biofertilizers (Rhizobium, Azotobacter, PSB) specifically promoted under the "Aapno Khet–Aapni Khaad" campaign. Trichoderma is a biocontrol fungus; Mycorrhiza aids phosphorus uptake; Pseudomonas fluorescens is a biocontrol agent — none fix nitrogen in legume nodules.