Factors to consider when draining rice

Deciding when to drain the water from your rice crop for harvest is one of the most important and difficult decisions in rice growing. In draining you must meet two objectives:

  1. You must ensure the field maintains adequate soil moisture until the crop reaches physiological maturity (26 to 28% grain moisture). The plants must not suffer moisture stress before this time or yield and grain quality will be reduced.
  2. The field should dry out sufficiently for a timely and efficient harvest at high grain moisture (20 to 22%) with harvest machinery not damaging the soil surface. In trying to achieve objective 2 you must not compromise objective 1.

Weather conditions in autumn when grain ripening, draining and harvest occur are highly variable. This seasonal variation from year to year is what makes the draining decision so challenging. 

David Troldahl and Brian Dunn, NSW Department of Primary Industries, Primefact 1390 1st edition, May 2014