Drone-ordered hill direct seeding: A new sowing technology with increased lodging resistance of direct-seeded rice

Direct-seeded rice is a labor-saving and simplified planting pattern, usually accompanied by an increase in lodging risk. Improving the population structure has been demonstrated as an effective approach for solving this problem, and changing the sowing method is the most direct way to construct a reasonable population structure. The objective of this study was to compare the lodging characteristics of rice plants under three sowing or transplanting methods, including drone-ordered hill direct-seeding (DHDS), manual broadcast direct-seeding (MDS), and machine transplanting (MTR). In a two-year field experiment, DHDS significantly reduced the lodging index of the fourth (N4) internode from the top of the rice stem compared with MDS. Over the two years, DHDS and MTR decreased the field lodging rate by an average of 99.3% and 79.2%, respectively. This improvement in lodging resistance was mainly attributed to the enhanced breaking resistance caused by increased internode diameter and culm wall thickness, rather than changes in plant height or bending moment. DHDS also increased the cellulose and starch content of the N4 internode by 17.7% and 50.3% compared to MDS, respectively. Furthermore, there was no significant difference in grain yield among the different treatments. Our results suggest that DHDS can enhance lodging resistance of direct-seeded rice as a feasible sowing method without compromising yield, and it was noninferior to MTR in terms of yield and lodging resistance.