Abstract: We investigated the impacts of different cropping patterns on aboveground growth and yield formation of rice (cultivars Huanghuazhan and Yexiangyoulisi) in a two-year field experiment with three cropping patterns: rice-oilseed rotation, rice-winter fallow, and rice-shrimp rotation. Rice yield and its formations, tillering dynamics, dry matter accumulation, leaf area index, leaf SPAD values, and canopy light interception were measured. The results showed that there were no significant differences in rice yield and aboveground growth characteristics between the rice-oilseed rotation and rice-winter fallow over two years. Compared with the rice-oilseed rotation, the rice-shrimp rotation significantly reduced the yields of rice cultivars Huanghuazhan and Yexiangyoulisi by 15.5%-16.4% and 14.4%-17.9%, respectively. The rice-shrimp rotation exhibited significant declines in effective panicle number, grains per panicle, tiller number, leaf area index, and dry matter accumulation in stems, leaves, and panicles. For Huanghuazhan and Yexiangyoulisi, dry matter accumulation in stems decreased by 13.5%-26.5% and 9.9%-22.7%, dry matter accumulation in leaves by 8.4%-23.2% and 7.4%-19.1%, and dry matter accumulation in panicles by 13.0%-22.2% and 16.8%-19.3%, respectively. Over the two years, SPAD values of the second uppermost leaves during the early growth periods were consistently lower in the rice-shrimp rotation compared to the rice-oilseed rotation. Canopy light interception showed a declining trend in the rice-shrimp rotation. These factors further affected dry matter accumulation in panicles and yield formation. In conclusion, the rice-shrimp rotation is not conducive to the aboveground population growth and the yield formation in rice.

Key words: rice-shrimp rotation, rice yield, tillering dynamics, dry matter accumulation, light interception rate