Which of the following practices can help in water conservation in agriculture? 1. Reduced or zero tillage of the land 2. Applying gypsum before irrigating the field 3. Allowing crop residue to remain in the fieldSelect the correct answer using the code given given below:

Key Points: Methods for Minimizing Water Stress and Improving Water Resources
Using Surface Residue Covers:
➤ Residue covers absorb raindrop energy, reducing soil aggregate disintegration and fine particle detachment.
➤ This process increases infiltration and reduces runoff, conserving water resources.
✅ Statement 3 is correct.

Contour Barriers and Conservation Tillage:
➤ Incorporating impermeable and permeable contour barriers downslope, coupled with reduced tillage or zero tillage, is an effective conservation agriculture practice.
✅ Statement 1 is correct.

Lime and Gypsum Incorporation:
➤ Using lime with or without gypsum mitigates toxic aluminum/manganese concentrations, promoting deeper rooting for enhanced soil moisture access.
➤ However, the official UPSC answer key does not consider this statement as correct in this context.
❌ Statement 2 is incorrect.

Conclusion
Correct statements: 1 and 3 only.