不同栽培模式对“早籼晚粳”双季稻光氮利用效率及产量的影响

【目的】开展多个因素集成的高产高效栽培模式研究,为水稻产量与资源利用效率协同提高的栽培模式提供技术途径。【方法】在南方双季稻区,设置4种栽培模式,分别为不施肥模式（早、晚季基本苗62.5和50.0万/hm²,不施氮肥,CK）,当地农民模式（在N0模式的基础上早、晚季分别施纯氮150和165 kg·hm^-2,基肥:蘖肥为7:3,FM）,高产高效模式（在FM模式的基础上早、晚季基本苗增加1倍以上,早、晚季施氮量分别减少20%和增加27%,基肥:蘖肥:穗肥比5:3:2,锌肥作基肥施入,T1）、再高产高效模式（在T1模式的基础上早、晚稻基本苗增加20%以上,增施有机肥,晚季施氮量增加14%,基肥、蘖肥和穗肥比例为4:3:3,垄厢栽培,T2）,研究这些栽培模式对“早籼晚粳”双季稻光氮利用效率及产量形成的影响。【结果】T2处理的平均周年产量为15.1 t·hm^-2,显著高于T1和FM处理,与FM处理相比,T2处理的早籼稻和晚粳稻产量分别提高了13.3%和24.9%;与FM处理相比,T2处理显著增加了早籼稻和晚粳稻公顷穗数,使得群体颖花数显著提高。T1处理平均周年产量为13.3 t·hm^-2,高于FM处理,表现为晚粳稻产量平均提高了9.5%、早籼稻产量略有下降。早稻季,T2处理成熟期干物质为12.30 t·hm^-2,显著高于T1和FM处理,群体生长速率高于T1和FM处理,表现为移栽—齐穗期群体生长速率显著提高;晚稻季,T2处理成熟期干物质为17.96 t·hm^-2,显著高于T1和FM处理,齐穗—成熟期群体生长速率显著高于CK,高于T1处理,且2018年差异达到显著水平。与FM处理相比,T2处理的早、晚季辐射利用率分别为1.05和1.25 g·MJ^-1,分别显著提高了31.7%和63.4%;T2处理早、晚季的氮肥农学利用率（AE_N）分别为28.8、14.7 kg·kg^-1,分别显著提高了61.6%和31.9%。【结论】 基于南方双季稻生态特点,以“定苗定氮”、垄厢增氧、其他措施增强灌浆活性为主集成了再高产高效栽培模式,实现了产量与光氮利用效率协同提高10%—20%的目标。

Effects of Different Cultivation Models on Solar Radiation-Nitrogen Use Efficiency and Yield of “Early Indica-Late Japonica” Double Rice

【Objective】In order to find the technical pathway to improve both grain yield and resource use efficiency in rice production, this study compared high yield and high efficiency cultivation models integrated by various cultivation measures. 【Method】Four cultivation models were established in a double rice-cropping region in south China, i.e., nitrogen-free cultivation model (CK: 62.5 and 50.0×10⁴ seedlings·hm^-2 in early and late season, respectively; 0 kg N·hm^-2 in both early and late seasons), local farming cultivation model (FM: 62.5 and 50.0×10⁴ seedlings·hm^-2 in early and late season, respectively; 150 and 165 kg N·hm^-2 in early and late season, respectively, with 70% as basal fertilizer and 30% as tillering fertilizer in both seasons), high yield and high-efficiency cultivation model (T1: 135 and 112.5×10⁴ seedlings·hm^-2 in early and late season, respectively; 120 and 210 kg N·hm^-2 in early and late season, respectively, with 50% as basal fertilizer, 30% as tillering fertilizer, and 20% as panicle fertilizer in both seasons; 5 kg Zn·hm^-2 as basal fertilizer in both early and late seasons), and more high-yield and high-efficiency cultivation model (T2: 176 and 137.5×10⁴ seedlings·hm^-2 in early and late season, respectively; 120 and 240 kg N·hm^-2 in early and late season, respectively, with 40% as basal fertilizer, 30% as tillering fertilizer, and 30% as panicle fertilizer in both seasons; 5 kg Zn·hm^-2 and 1.8 t·hm^-2 organic fertilizer as basal fertilizer in both early and late seasons; bed cultivation in both early and late seasons). Solar radiation and nitrogen use efficiency and yield of rice were compared among these four cultivation models.【Result】 Average annual yield under T2 was 15.1 t·hm^-2, which was significantly higher than those under T1 and FM. Compared with FM, the yield of early indica rice and late japonica rice under T2 was increased by 13.3% and 24.9%, respectively. T2 significantly increased panicle number per unit land area and consequently spikelet number per unit land area for both early indica rice and late japonica rice. Average annual yield under T1 was 13.3 t·hm^-2, which was higher than that under FM. Compared with FM, the yield of late japonica rice was increased by 9.5% while the yield of early indica rice was slightly decreased under T1. In the early season, dry matter accumulation at maturity under T2 was 12.30 t·hm^-2, which was significantly higher than those under T1 and FM. The crop growth rate from transplanting to flowering was significantly higher under T2 than under T1 and FM. In the late season, dry matter accumulation at maturity under T2 was 17.96 t·hm^-2, which was significantly higher than those under T1 and FM. The crop growth rate from flowering to maturity was higher or significantly higher under T2 than under FM and T1. Solar radiation use efficiency under T2 in early season and late season was 1.05 and 1.25 g·MJ^-1, respectively, which was improved by 31.7% in the early season and 63.4% in the late season as compared to FM. Nitrogen agronomy use efficiency under T2 in early season and late season was 28.8 and 14.7 kg·kg^-1, respectively, which was enhanced by 61.6% in the early season and 31.9% in the late season as compared to FM. 【Conclusion】Based on ecological characteristics of double-cropped rice in south China, 10%-20% increases in rice yield as well as solar radiation and nitrogen use efficiency can be achieved by the adoption of T2 model which is integrated by increasing seedling number and reducing nitrogen rate, improving soil oxygen content by bed cultivation, and enhancing the activity of grain filling by other cultivation measures such as Zn fertilizer.