Which of the following statements can help in water conservation in agriculture?1.Reduced or zero tillage of the land2.Applying gypsum before irrigating the field3.Allowing crop residue to remain in the fieldSelect the correct answer using the code given below:

1. A

   1 and 2 only

   Option (a) is 1 and 2 only. Reduced or zero tillage does conserve soil moisture, but applying gypsum is a sodic-soil amendment (calcium) rather than a water-conservation practice as such. Statement 2 is not a water-saving method in the sense of the question. This option is not the key.

2. B

   3 only

   Option (b) is 3 only. Residue mulch does help, but zero tillage also conserves water, so omitting statement 1 is incomplete. This option is therefore wrong.

3. C

   1 and 3 only

   Reduced/zero tillage cuts evaporation and runoff; leaving crop residue as mulch shades soil and improves infiltration. Gypsum before irrigation is not listed as a water-conservation technique. Hence 1 and 3 only is the official key.

4. D

   1, 2 and 3

   Option (d) is 1, 2 and 3. Including gypsum as a water-conservation measure is the error. This option is not the key.

Summary. Official key is (c) 1 and 3 only. Conservation agriculture saves water by less tillage and by residue cover. Gypsum is used to reclaim alkali/sodic soils and improve structure; it is not itself a method of saving irrigation water in the question’s sense. Statements 1 and 3 help; 2 does not. Only that pair is correct.