Chen Yuanwei, Zheng Huabin, Wang Weiqin, Tang Qiyuan
College of Agronomy Hunan Agricultural University, Changsha 410128, PR China.
Collaborative Innovation Center for Grain and Oil Crop in Southern Paddy Field, Changsha 410128, PR China.
Heliyon. 2023 Feb 24;9(3):e14042. doi: 10.1016/j.heliyon.2023.e14042. eCollection 2023 Mar.
Forage-food dual-purpose ratoon rice cropping (FFRR) is used to balance forage demands with ratoon rice grain yields, that is whole plant (stem and sheath, panicles) cuttings in the main season are used as forage, and rice in the regeneration season is used as food. In this study, the local ratoon rice production system as the control, we were carried out the field experiment of cultivation practices (cutting time and cutting height), and investigated the system productivity, economic benefits, carbon footprints and energy use efficiency. The energy use efficiency, energy productivity and energy profitability increased with cutting time delay, and cutting height decreased. Significant differences of these index were observed among the treatments for cutting time and cutting height (p < 0.05). Carbon efficiency and carbon sustainability index was increase with cutting time delay, and there was significant difference among the treatment of cutting time in 2018 (p < 0.05), the minimum carbon footprint of FFRR was 78.6 kgCO t averagely at the cutting time of 30 days after the flowering stage. In 2018, the maximum net income of FFRR was 30,577 CNY hm at a cutting time of 30 days after the flowering stage while the stubble height was 10 cm, and dependent on the forage yield of the main crop; in 2019, the maximum net income of FFRR was 27,326 CNY hm at a cutting time of 10 days after the flowering stage while the stubble height was 10 cm, and dependent on the grain yield of the ratoon crop. Therefore, the optimal cultivation practice of the FFRR (cutting at 30 days after the flowering stage and with a stubble height of 10 cm) showed higher carbon and energy use efficiency, economic benefits of the FFRR were fluctuated with the price of forage of the main crop and rice grain of the ratoon crop.
粮草两用再生稻种植（FFRR）用于平衡饲料需求与再生稻产量，即在主季将整株（茎、鞘、穗）收割用作饲料，再生季的水稻用作粮食。本研究以当地再生稻生产系统为对照，开展了栽培措施（收割时间和留茬高度）的田间试验，并调查了系统生产力、经济效益、碳足迹和能源利用效率。能源利用效率、能量生产率和能源利润率随着收割时间的推迟而提高，留茬高度降低。在收割时间和留茬高度的处理间，这些指标存在显著差异（p < 0.05）。碳效率和碳可持续性指数随着收割时间的推迟而增加，2018年收割时间处理间存在显著差异（p < 0.05），FFRR的最小碳足迹平均为78.6 kgCO₂/t，出现在开花期后30天的收割时间。2018年，FFRR的最大纯收入为30577元/hm²，出现在开花期后第30天的收割时间且留茬高度为10 cm时，并且取决于主作物的饲料产量；2019年，FFRR的最大纯收入为27326元/hm²，出现在开花期后第10天的收割时间且留茬高度为10 cm时，并且取决于再生作物的稻谷产量。因此，FFRR的最佳栽培措施（开花期后30天收割且留茬高度为10 cm）显示出更高的碳和能源利用效率，FFRR的经济效益随主作物饲料价格和再生作物稻谷价格而波动。
