Effect of Irrigation and Cultivation Modes on Growth, Physiology, Rice Yield Parameters and Water Footprints

Under the background of the worsening global food and water crisis, efficient agricultural practices have become increasingly important. This study investigated the impact of different irrigation and cultivation modes on rice growth parameters, gas exchange, rice yield components, and water footprints in Jiangsu, China. Four treatments were employed in a randomized complete block design with three replications: (i) transplanted rice with frequent shallow irrigation (T-FSI), (ii) transplanted rice with rain-catching and controlled irrigation (T-RCCI), (iii) direct-seeded rice with frequent shallow irrigation (D-FSI), (iv) and direct-seeded rice with rain-catching and controlled irrigation (D-RCCI). The results revealed that the D-RCCI treatment significantly improved growth and physiological parameters. The D-FSI treatment drastically increased rice yield whereas T-RCCI increased the stem bending resistance and reduced lodging risk. The water footprint analysis showed significant water savings by optimized management practices. Compared to T-FSI, the T-RCCI, D-FSI, and D-RCCI treatments reduced the blue-green water footprint by 33%, 25%, and 25%, respectively. Additionally, water production efficiency increased by 13%, 106%, and 154% for T-RCCI, D-FSI, and D-RCCI respectively. The water footprint per unit yield of T-RCCI, D-FSI, and D-RCCI treatments was significantly reduced by 12%, 5,3%, and 63% compared to T-FSI. Overall, D-RCCI is the optimal strategy for rice cultivation in Jiangsu province and similar climatic areas due to its positive impact on yield, water savings, and environmental benefits.