Using olive mill waste compost with sprinkler irrigation as a strategy to achieve sustainable rice cropping under Mediterranean conditions

Traditional rice ( Oryza sativa L.) cropping systems under flooding irrigation combined with conventional tillage management are under increasing threat due to a loss of soil quality and a scarcity of water resources, especially in Mediterranean environments. Hence, the development of such management strategies as no-tillage, the application of organic amendments, and water-saving methods could be vital in enhancing the sustainability of rice crops. This work tests the combination of various management systems for growing rice under Mediterranean conditions. It assesses for the first time their influence on soil properties and rice yield components. A field experiment was carried out in southern Spain over 3 years (2015–2017) with six treatments: tillage and continuous flood irrigation either without or with application of two-phase olive mill waste compost; tillage and sprinkler irrigation either without or with application of mill waste compost; direct seeding (no tillage) and sprinkler irrigation either without or with application of mill waste compost. Applying mill waste compost in combination with sprinkler-rice systems improved significantly the soils’ properties. Sprinkler-rice yield was similar to that of rice under tillage and flooding, but it used less irrigation water. In 2017, the greatest rice yield occurred under tillage and sprinkler irrigation with application of mill waste compost (8581 kg ha -1 ), showing the importance of soil organic matter on yields. Additionnally, flooding increased significantly weed density because it lowered herbicide efficacy, making weed control a key issue for rice yields. Thus, the novelty of this communication is showing that the application of mill waste compost combined with sprinkler irrigation may be a sustainable alternative for rice crops under Mediterranean conditions, increasing the water efficiency and reducing weed pressure, while improving different soil properties.