Mulching Improved Soil Water, Plant Growth, and Seed Yield of Sunflower Under Raised Bed–Furrow Irrigation Method

Plastic film mulching combined with raised bed–furrow irrigation is an effective technique for enhancing the seed yield, oil contents, and plant-level water use efficiency of sunflower cultivation, while also optimizing water footprint. In this study, a field experiment was carried out at the experimental station of the Department of Irrigation and Drainage during 2023–2024. The trial involved three types of raised bed–furrow irrigation (raised beds with 60, 45, and 30 cm ridges and 30 cm furrows) with and without mulching practices. The results revealed that the treatments combining mulching with raised beds showed higher soil temperature and moisture contents compared to non-mulching treatments. The highest seed yield and oil content were recorded in furrow irrigation with mulching, representing a 35% increase in yield and a 28% increase in oil content compared to the control treatment. Seed yield was positively correlated with oil content. Additionally, the highest plant-level water use efficiency was observed in a raised bed 45 cm in size with mulching, while the highest total water footprints were recorded in a raised bed with a 60 cm ridge and non-mulch treatment, both exceeding the control treatment. It is concluded that sunflower cultivation under mulching combined with raised bed–furrow irrigation significantly enhances crop and water productivity.