To manage water resources for agricultural output in areas with limited water resources, innovation and sustainable methods must be used. The aim of this book chapter is to delve into the synergistic effects of hydrothermal regime, growth characteristics and consumption of water, by onion crop over different mulch layer of Coconut husk. Within an altered crop growing environment, the application of mulch exhibits beneficial impacts on the retained soil moisture, crop growth and productivity of crop. In order to assess the potency of readily available Cocos nucifera husk in retaining soil moisture field trials have been carried out. The onion crops utilized a variety of application rates and revised watering schedule accordingly. The study’s conclusions demonstrate that the use of coconut husk mulch reduced the maximum soil temperature, promoted plant development, and decreased the overall amount of irrigation needed. The study also revealed for higher permitted depletion having Maximum Allowable Depletion (MAD) 70% the overall water requirement is low while a higher value of water need for a lower permitted depletion of MAD value 30%.