【目的】明确杂交稻70 g以下低播量精量穴播和条播对育秧效果及机插特性的影响,突破生产中杂交稻机插的技术瓶颈。【方法】以中浙优1号和甬优1540两个杂交稻品种为材料,利用机插标准9寸盘,设置机械穴播和条播两个精量播种方式,并以机械流水线撒播为对照,穴播规格为16(纵向)×34(横向)穴,条播为纵向16条,以穴播5粒、3粒及2粒的播种量进行播种试验。考查了低播量下不同播种方式对秧苗生长影响及配套取秧效果【结果】1)低播量下不同播种方式对秧苗成苗率的影响不大。2)降低播种量提高秧苗生长一致性,且穴播和条播秧苗生长一致性好于撒播。3)与撒播相比,精量穴播和条播能够在低播量下提高秧苗根系盘结力和成毯性,中浙优1号和甬优1540根系盘结力比撒播平均高75.4%和81.0%,播量每穴3粒时即能有效成毯,穴播和条播差异不大。4)精量穴播和条播能够显著降低低播量下机插漏秧率,中浙优1号和甬优1540机插漏秧率平均分别比撒播低76.3%和74.6%,穴播和条播下,两个品种每穴播量3粒的漏秧率均在1%以下,与撒播相比降幅在10个百分点以上。5)精量穴播和条播机插取秧苗数均匀度比撒播要好,两个品种预期取秧2~5苗(5粒)、1~3苗(3粒)和1~2苗(2粒)比例均达80%以上,中浙优1号和甬优1540机插苗数均匀度平均比撒播高121.2%和67.0%,其中,穴播机插取秧苗数均匀度及预期取秧苗数比例高于条播。【结论】精量穴播和条播可以解决目前杂交稻机插用种量大、漏秧率高和机插取秧苗数均匀度差的问题。

【Objective】 The purpose of the study is to ascertain the effect of precise hill-sowing and drill-sowing methods on seedling raising and the characteristics of mechanized transplanting of hybrid rice with a low seed sowing rate below 70 g, and to further break the current technical bottleneck in mechanized transplanting process of hybrid rice. 【Method】 In this study, Zhongzheyou 1 and Yongyou 1540 were mechanically hill-sowed and drill-sowed in standard seedling raising trays with mechanized broadcasting as the control. The hill-sowing specification was 16×34 hill, and 16 drills were set in longitudinal direction for drill sowing. The seed sowing rates were 5 seeds, 3 seeds, and 2 seeds per hill for hill sowing, and the same seed rates were set in drill sowing. The effects of different sowing methods on the growth of seedlings and their mechanical transplanting characteristics were investigated. 【Results】 1) Sowing methods presented no significant effect on seedling percentage with a reduction in seeding rate. 2) A reduction in seeding rate improved rice seedling consistency, especially in hill sowing and drill sowing as compared with broadcasting. 3) In comparison with seed broadcasting, under hill seeding and drill seeding, seedling roots were more entwined as seedling mats. Under hill-sowing and drill sowing, Zhongzheyou 1 and Yongyou 1540 had 75.4% and 81.0% higher intertwining force than that of broadcasting, respectively. Precise hill- and drill-sowing generated effective seedling blanket without significant difference between the two treatments, while broadcast sowing did not. 4) Hill sowing and drill sowing significantly reduced the missed hill percent of machine transplanting. The missed hill percent of Zhongzheyou 1 and Yongyou 1540 under hill sowing and drill sowing were 76.3% and 74.6% lower than that of broadcast sowing in average, respectively. The missed hill percent for hill-seeding and drill-seeding with 3 seeds per hill was below 1%, 10% lower than that of broadcast sowing. 5) The uniformity of machine-transplanted seedling under hill sowing and drill sowing were better than that of broadcast sowing. And the proportion of the treatments with expected seedling-catching number in mechanized transplanting (2 to 5 seedlings with 5 seeds per hill, 1 to 3 seedlings with 3 seeds per hill and 1 to 2 seedlings with 2 seeds per hill) for the two cultivars were all above 80% in hill-sowing and drill-sowing in combination with machine transplanting, and the seedling uniformity of machine-transplanted Zhongzheyou 1 and Yongyou 1540 was 121.2% and 67.0% higher than that under broadcast sowing. Meanwhile hill sowing had a better result than drill sowing. 【Conclusion】 Precision hill seeding and drill seeding provide an alternative measure to current problems such as large amount of seeds, high missed hill percent and uneven seedling taking in the process of machine transplanting of rice.