Effect of Dense Sowing Nursery on Seedling Quality and Picking Characteristics for Mechanized Transplanting in Northern japonica Rice

doi:10.16819/j.1001-7216.2025.250105

Abstract

Abstract:

【Objective】 To study the effects of dense sowing on rice seedling quality and seedling-picking characteristics under mechanized transplanting, and to explore its role in enhancing rice nursery efficiency and mechanized transplanting performance. 【Method】 In 2024, using Liaojing 419 as the test variety, a seedling nursery experiment was conducted. The control treatment (CK) used the conventional farmer sowing rate of 100 g per tray (58 cm × 28 cm). Four dense-sowing treatments were established: 125 g (ISR1), 150 g (ISR2), 175 g (ISR3), and 200 g (ISR4) per tray. The study investigated the effects of different sowing rates on rice seedling quality and seedling-picking characteristics during mechanized transplanting, aiming to elucidate the relationship between the physiological and biochemical changes in dense-sown seedlings and the operational quality of mechanized transplanting. 【Result】 The whole-tray biomass of rice seedlings increased significantly with increasing sowing rate, reaching its maximum at 175 g per tray(ISR3). The root intertwining force of seedlings also significantly increased under ISR3, averaging increases of 35.6% and 29.1% compared to CK, respectively. The individual seedling biomass decreased significantly due to high sowing rates, accompanied by reduced antioxidant enzyme activities, lower soluble sugar content, and altered expression of stress resistance-related genes. The uniformity of plant height and stem base width decreased by 1.3%-2.6% and 0.6%-3.7% in ISR1-ISR3 compared to CK, respectively, and decreased significantly by 7.2% and 9.3% in ISR4, respectively. The injured seedling rate during mechanized transplanting showed a linear positive relationship with sowing rate. The average injury rate was 4.1% for ISR1-ISR3 and 9.8% for ISR4. Treatments ISR2 and ISR3 maintained relatively higher seedling plumpness, seedling vigor index, and lower seedling injury rates. The actual number of seedling trays used per hectare for mechanized transplanting in ISR1-ISR4 decreased by 53.2-148.1 trays/hm² compared to CK. Consequently, the manual operational efficiency during mechanized transplanting significantly improved by 17.2%-40.2%. 【Conclusion】 Dense-sowing nursery increases whole-tray biomass and root intertwining force. A sowing rate of 150-175 g per tray maintained relatively high individual seedling quality, significantly reduced tray usage by 36.2%, and greatly improved the operational efficiency of mechanized transplanting. This approach can be adopted as a high-quality and efficient mechanized transplanting option for japonica rice in Northern China.

Key words: rice, dense sowing, picking characteristics, mechanized transplanting

摘要：

【目的】研究密播乳苗对机插水稻秧苗质量及取秧特性的影响，探明其对水稻育秧及机插效率的提升作用。【方法】于2024年以辽粳419为试材，以农户常规播种水平100 g/盘(长×宽为58 cm×28 cm, CK)为对照，设置125 g/盘(ISR1)、150 g/盘(ISR2)、175 g/盘(ISR3)、200 g/盘(ISR4)共4个密播处理，进行育苗试验，探究不同播种量对水稻秧苗质量及机插取秧特性的影响，阐明密播乳苗的秧苗生理生化特性与机插作业质量的关系。【结果】水稻秧苗整盘生物量随着播种量提高显著增加，在175 g/盘(ISR3)达到最大，且秧苗的根系盘结力显著提高，分别平均增加了35.6%和29.1%。高播种量处理下水稻秧苗个体生物量显著下降，秧苗抗氧化酶活性、可溶性糖含量降低，抗逆相关基因的表达受到影响。株高均匀度和茎基宽均匀度在ISR1~ISR3下较对照分别降低了1.3%~2.6%和0.6%~3.7%，ISR4分别显著降低了7.2%和9.3%；机插伤苗率与播种量呈线性正关系，在ISR1~ISR3下平均伤苗率为4.1%，ISR4下为9.8%，ISR2~ISR3处理维持较高的秧苗充实度、壮苗指数和较低的伤苗率。机插实际用秧盘数ISR1~ISR4较CK降低了53.2~148.1盘/hm²，机插人工操作效率显著提升17.2%~40.2%。【结论】密播乳苗育秧提高了整盘秧苗生物量和根系盘结力，150~175 g/盘播种量可以维持较高的个体秧苗质量，显著降低秧盘用量36.2%，极大提升了机插作业效率，可作为北方粳稻地区高质高效机插秧作业选择。

关键词: 水稻, 密播乳苗, 取秧特性, 机插

DONG Liqiang, ZHANG Yikai, YANG Tiexin, FENG Yingying, MA Liang, LIANG Xiao, ZHANG Yuping, LI Yuedong. Effect of Dense Sowing Nursery on Seedling Quality and Picking Characteristics for Mechanized Transplanting in Northern japonica Rice[J]. Chinese Journal OF Rice Science, 2025, 39(4): 516-528.

董立强, 张义凯, 杨铁鑫, 冯莹莹, 马亮, 梁潇, 张玉屏, 李跃东. 北方粳稻密苗机插育秧对秧苗素质及取秧特性的影响[J]. 中国水稻科学, 2025, 39(4): 516-528.

Figures/Tables 13

References 37

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基因 Gene	正向引物 Forward sequence (5'-3')	反向引物 Reverse sequence (5'-3')
Actin-OS-GAPDH	TACAGCTCTCGCGTTGTTGA	CATCATGCGAAAAGCCAGCA
OsLPXC	TGAAAAATTGCGTTCTGCTG	GCAAGAAGCGAGAAATCACC
OsSPX1	AGCAGCAGGAACTGTGGAAT	CCCGGTACTATCTCCAGCAA

基因 Gene	正向引物 Forward sequence (5'-3')	反向引物 Reverse sequence (5'-3')
Actin-OS-GAPDH	TACAGCTCTCGCGTTGTTGA	CATCATGCGAAAAGCCAGCA
OsLPXC	TGAAAAATTGCGTTCTGCTG	GCAAGAAGCGAGAAATCACC
OsSPX1	AGCAGCAGGAACTGTGGAAT	CCCGGTACTATCTCCAGCAA

处理 Treatment	横向取苗 Horizontal seedling width (mm)	纵向取苗 Vertical seedling length(mm)	取苗面积 Seedling area (mm²)	理论取苗株数 Theoretical seedling number	单盘理论取苗次数 Theoretical hill number per tray	理论用苗盘数 Theoretical tray number(No./hm²)
CK	14	14	196	4.43	828.57	251.45
ISR1	14	12	168	4.62	966.67	215.53
ISR2	14	10	140	4.43	1160.00	179.61
ISR3	11	11	121	4.46	1370.91	151.97
ISR4	11	10	110	4.74	1508.00	138.16

处理 Treatment	横向取苗 Horizontal seedling width (mm)	纵向取苗 Vertical seedling length(mm)	取苗面积 Seedling area (mm²)	理论取苗株数 Theoretical seedling number	单盘理论取苗次数 Theoretical hill number per tray	理论用苗盘数 Theoretical tray number(No./hm²)
CK	14	14	196	4.43	828.57	251.45
ISR1	14	12	168	4.62	966.67	215.53
ISR2	14	10	140	4.43	1160.00	179.61
ISR3	11	11	121	4.46	1370.91	151.97
ISR4	11	10	110	4.74	1508.00	138.16

处理 Treatment	叶龄 Leaf age	SPAD	株高 Plant height(cm)	茎基宽 Stem base width(mm)
CK	2.78±0.04 a	29.26±0.56 a	14.80±0.18 a	2.17±0.03 a
ISR1	2.54±0.03 b	28.70±0.19 a	14.48±0.19 ab	1.79±0.02 b
ISR2	2.47±0.03 bc	28.44±0.69 a	14.15±0.18 b	1.72±0.02 c
ISR3	2.44±0.03 c	28.35±0.42 a	13.19±0.17 c	1.66±0.02 c
ISR4	2.16±0.03 d	28.05±0.38 a	12.11±0.16 d	1.58±0.02 d