How many irrigations does chana need and at which stages on light soil?

On my light soil I run the water through shallow furrows rather than flooding the field flat, so it reaches the roots without soaking the crown, which used to leave standing pockets that turned into wilt patches. The placement of the water matters as much as the amount on sandy land.

In a year with a good late winter shower I have skipped the pre-flowering irrigation and let the rain do that job, then given just the pod-filling water. Counting the rain as one of your waterings stops you over-watering, and gram clearly does better a touch dry than a touch wet.

On my sandy loam I give just one irrigation before flowering and one at pod filling. More than that and the plants run to leaf with fewer pods.

Do not start the irrigations too early on light soil, the early lush growth from too much water early gives you a tall leafy plant with few pods. I hold off and give the first water near flowering, which keeps the plant compact and pushes the energy into pods rather than leaf.

Keep each irrigation light and never let water stand. On my tubewell I used to flood the gram like wheat and got wilt and lush growth. Now I give a gentle, quick irrigation and let it drain, and the crop stays healthy with good podding.

Watch the weather before the pod-filling irrigation. If rain looks likely or the soil still feels moist below the surface, I skip it, because gram punishes you more for too much water than too little. The pod-filling water only pays if the soil has actually dried out.