水稻机插秧盘播种覆盖土厚度对秧苗生长的影响

Effect of Covering Soil Thickness in Seedling Tray on the Rice Seedlings Growth for Machine Transplanting

【目的】为明确水稻机插育秧覆盖土厚度对秧苗生长的影响。【方法】以甬优1540和天优华占为材料,利用9寸标准机插秧盘进行试验,利用基质和稻田土进行播种,设置3个育秧土覆盖厚度处理(T_(1),底土2L+覆盖土2L;T_(2),底土3L+覆盖土1L;T_(3),底土3.6 L+覆盖土0.4 L),考察秧苗成苗率,苗高和叶龄、以及干质量和秧苗充实度的变化。【结果】(1)秧盘覆盖土过厚不利于秧苗成苗,T_(2)处理秧苗成苗率最高,采用基质育秧的种子成苗率要好于采用稻田土育秧。(2)叶龄变化和育秧土覆盖厚度密切相关,叶龄表现由高到低依次为T_(1)、T_(2)和T_(3),同时基质育秧的叶龄大于稻田土育秧。T_(1)和T_(2)处理苗高差异不明显,但均高于T_(3)处理,2个品种间以及基质类型间趋势一致。(3)T_(2)处理秧苗均匀度平均比T_(1)和T_(3)处理高33.8%和41.0%,T_(2)处理弱苗比例最低,分别比T_(1)和T_(3)处理平均降低51.7%和74.3%,2个品种趋势一致,其中基质育秧秧苗均匀度高于稻田土育秧。(4)基质育秧秧苗干质量高于稻田土育秧,其中T_(1)和T_(2)处理干质量差异不大,但均显著高于T_(3)处理。T_(2)处理秧苗充实度最高,两个品种在两种育秧土间的表现趋势一致。【结论】在水稻机插育秧时,秧盘覆盖土要有适当的厚度,9寸盘播种底土3L,覆盖土1L有最佳的效果。

Objective]This study aims to clarify the effect of the cover soil thickness in seedling tray on the growth of rice seedlings for machine transplanting.Method]The experiment used‘Yongyou 1540’and‘Tianyou Huazhan’as test materials,a 9-inch standard machine-transplanting tray was also used in conduct‐ing the experiment.The substrate and paddy soil were used for sowing and subjected to three cover soil treat‐ments(T_(1),subsoil 2 L+cover soil 2 L;T_(2),subsoil 3 L+cover soil 1 L;T_(3),subsoil 3.6 L+cover soil 0.4 L)to investi‐gate the seedling rate,seedling height,leaf age,dry weight and the seedling fullness.[Result]The results showed that:(1)covering thick soil on the seedling tray was not conducive to the seedling formation.The forma‐tion rate of the seedlings raised by the substrate was better than that raised by the paddy soil.(2)The change of leaf age was closely related to the thickness of cover soil,and the hierarchy of leaf age performance was T_(1)>T_(2)>T_(3).In addition,the leaf age of seedling raised in substrate exceeded that of seedling raised in paddy soil.There was no significant difference in seedling height between T_(1) and T_(2) treatments,and they were both higher than that of T_(3)treatment.The trends were consistent between the two varieties and between the types of substrates.(3)The seedling uniformity of T_(2) treatment was 33.8%and 41.0%higher than that of T_(1) and T_(3) treatments.The pro‐portion of weak seedlings of T_(2) treatment was the lowest,which was 51.7%and 74.3%lower than that of T_(1) and T_(3) treatments.The trends of the two varieties were the same.The uniformity of seedlings was higher than that of rice seedlings raised by paddy soil.(4)The dry weight of seedlings raised in substrate was higher than that in paddy soil.The difference in dry weight between T_(1) and T_(2) treatments presented no significant difference,and they were both significantly higher than that of T_(3) treatment.T_(2)treatment had the highest seedling plumpness,and the performance trends of the two varieties in the two seedling soils were consistent.[Conclusion]When raising rice seedling for machine transplanting,the optimal thickness of seedling tray cover soil was 9-inch standard tray seeding 3 L subsoil and 1 L cover soil.