Stubble Righting Increases the Grain Yield of Ratooning Rice After the Mechanical Harvest of Primary Rice

Ratoon rice production is an effective approach to improve overall rice productivity, while incurring the lowest operation- and/or production-related costs. Stubble management and the growth optimization of ratoon crops are examples of production systems that remain an issue that needs to be addressed properly to maximize the benefits. The present study was conducted considering the objective that stubble righting could substantially reduce the adverse effects of mechanical primary rice harvesting on RR production. Field experiments were conducted during the 2017 and 2018 rice seasons with three stubble righting treatments, i.e., CK, which included the use of stubbles without righting after rolling by the machine; T1, which included the use of stubbles righting by manual method after rolling by a machine; and T2, which included the use of stubbles without rolling by the machine, in Jiujiang, Jiangxi Province, China. The growth- and yield-related attributes of RR were investigated. The grain yield trends were ordered as T2 > T1 > CK. Compared with CK, T1 increased the grain yield by 17.17% and 58.87% in 2017 and 2018, respectively. The grain yield improvement in the T1 treatment resulted from the increased total dry weight, panicle number per m2, bud number, and regulation of the allocation bud number of RR compared with CK. Moreover, a significant correlation was noted between the grain yield and the total dry weight and panicle number per m2. Overall, stubble righting after machine rolling (during the harvest of the main crop) lowered the yield loss of RR due to its improved growth enhancement effects. Therefore, stubble righting is a better management approach to improve the growth and productivity of RR in rice production systems in China.