Effect of watering in no-till grain

I have been trying no-till grain for some time now and not successful to get a yield. I used to water this particular field when there was water shortage. Now I starts to think that watering upsets the natural cycle. For example, after November, there won't be any rain in Kerala climate usually and crops/weeds starts receding. By March, April all the weeds would have dried normally and with the first rain, if we sow the seeds of the crop, then there is not much weed competition. But if we water and grow some crops, there will be moisture in the field and weeds, otherwise some crop should be growing at the field all the time.

Please see the picture of an area where I had grown sunhemp at the start of the rain and the field after the end of summer. All the grass/sunhemp had completed the cycle, the field was weed free. This was done in 2013.

At this point I think, may be a when rain has started, if it was not sufficient, may be some watering might be OK, but completely upsetting the natural cycle may not be good, if we are doing no-till natural farming.

In this type of field, we have to start rice, at the first rain itself, otherwise weeds will establish. When it rained, if it was not sufficient to make rice germination, may be some watering may be OK, these are all my thinking, it may be prove right or wrong.