【作者】 邵文娟；

【导师】 朱庆森； 杨建昌； 沈建辉；

【作者基本信息】 扬州大学 ， 作物栽培学与耕作学， 2004， 硕士

【摘要】 2002～2003年两年间以武运粳7号和武育粳3号为供试材料，进行了机插中苗双膜育秧和软盘育秧的落谷密度、秧床床土培肥以及移栽秧龄对秧苗形态、秧苗质量、最终产量及其构成影响的试验，结果如下： (1) 秧龄在3叶1心初期移栽，田间发根力、单位茁高干重、地上部干重和苗基粗等重要苗质指标均随落谷密度增大而变劣，落谷密度最稀的处理(170.7粒／dm~2)苗质虽显著(或明显)优于其它处理，但机插缺穴率高和平均每穴苗数少，稻谷产量反而显著低于其它处理。落谷密度在229.4粒～400.1粒／dm~2之间，苗质虽随落谷密度增加而呈下降的趋势，但大田稻谷产量处理间差异不显著。而从提高秧龄弹性的要求出发，双膜育秧中苗移栽的落谷密度以230粒／dm~2左右为宜。 (2) 除170.7粒／dm~2外，其它处理秧苗地上部干重的峰值出现在播后20天，叶龄为3.8～4.1时，其后秧苗干重下降或不增长，苗质变劣，苗质下降的速率随落谷密度的增大而加大，可见在本试验条件下超秧龄的临界期在叶龄3.8～4.1时。 (3) 床土培(施)肥量较多的处理田间发根力、苗干重等苗质指标显著或明显优于培肥量少的处理，且大田分蘖发生早，最高茎蘖数高，但其成穗率降低，每穗粒数偏少，处理间稻谷产量差异缩小，不达显著水平，然而产量随床土培(施)肥量增加而增加的趋势仍明显存在。依此试验的数据分析进而提出了该品种机插中苗壮秧指标：苗高12cm，苗基粗度2.7mm，糖氮比1.0～2.0。 (4) 从16天秧龄到21天秧龄的秧苗田间发根力、茎鞘淀粉含量及单位苗高干重等秧苗素质诸指标均呈上升趋势；而从21天秧龄到35天秧龄时，秧苗素质明显下降，主要表现为田间发根力和茎鞘淀粉含量均大幅下降。随着秧龄的增加，秧田的成苗率和大田成活率下降，使得移栽后的每穴苗数减少，缺穴率上升，大田成苗数减少。各秧龄条件下落谷密度大的处理大田成苗数高于落谷密度小的处理。16天秧龄落谷密度大的条件下大田成苗数随着培肥量的增加而减少。21天和35天秧龄，两种落谷密度下大田成苗数均随着床土培肥量的增加而减少。此结果反映了床土培(施)肥、落谷密度和秧龄对秧苗素质影响的互作效应，对机插轻简育秧技术措施的制定有很好的参考价值。 (5) 产量随着移栽秧龄的增加显著下降。各移栽秧龄下的秧田落谷密度对产量的影响不显著；16天移栽秧龄秧田床土培肥量对产量的影响亦不显著；21和35天移栽秧龄落扬州大学硕士学位论文谷密度为240粒/dm“的条件下，产量随着床土培肥量的增加显著增加;落谷密度为360粒/dm“的条件下产量随着床土培肥量的增加呈下降趋势。三试验因素对大田产量的影响力的顺序是:秧龄>床土培肥>落谷密度。这提示在机插秧栽培中适期早栽是首要技术关键。产量构成因素中单位面积穗数与产量呈极显著正相关，相关系数达0.9404，‘，可见机插秧的大田单位面积穗数是影响产量最重要的因素。 (6)所有试点培肥前床土三要素速效养分含量的差异均较大，其中碱解氮含量的变幅为56.5一1 58.3mg/kg，速效磷含量的变幅为2.1一56.9mg/kg，速效钾含量的变幅为69.0一305.7 mg/kg。比较三地床土碱解氮对秧苗质量的影响总体表现为，建湖的秧苗质量差于其它两地，而其床七培肥后的碱解氮含量远远高于其它两地;全试验各试点(处理)的田间发根力与床土碱解氮含量呈二次曲线关系，说明在床土碱解氮含量比较低时随培肥量增加发根力增强，而碱解氮含量超过一定界限后，其含量再提高则发根力随之下降。此外，床十培肥量对产量的影响，秧龄21天以后，落谷密度大的条件下，随着培肥量增大，产量总体仁呈下降的趋势。由此可见，机插中苗的床土根据其基础地力，因土适量培肥是非常必要的。 (7)适宜的苗高是机插中苗壮苗的重要指标，机插中苗叶龄<3.6的秧苗苗高主要取决于第3叶的叶片和叶鞘长。本试验中的床土三要素速效养分含量与秧苗的第3叶叶片和叶鞘长均呈显著或极显著正相关。根据床土三要素速效养分含量与第3叶叶片和叶鞘长的回归关系(线性正相关)得出，培育适合机插的壮苗苗高12cm、第3叶叶片长6.scm、时-鞘长5.scm的床土三要素速效养分含量指标应分别为:碱解氮204.7一225.9mg/kg，速效磷56.7一59.8 mg/kg，速效钾287.7一346.5 mg/kg。这是一个目前可供参考的床土三要素培肥指标.而其与土壤质地、应用的品种、育秧季节的温度和秧龄等条件的关系还有待进一步深入研究。更多还原

【Abstract】 In 2002-2003, with Wu Yun Jing 7 and Wu Yu Jing 3 as materials, the morphology of the seedlings, seedlings quality , grain yield and its components were investigated under various treatments of sowing densities, seedbed soil fertilizing and seedling ages in raising medium-seedlings for mechanical transplanting of rice. The results are as follows:(l)When the seedling was transplanted at the leaf age of just after 3, the main indices of seedling quality such as root-developing ability in field, the ratio of dry weight to seedling height, above ground dry weight and the stem thickness at the base, were worsened with the increase of the sowing densities. The indices for the least density ( 170.7 grains/dm2) treatment were significantly or obviously superior to other treatments, but its grain yield was significantly lower than others else due to higher empty hill percentage and fewer seedlings per hill in field. Although there existed a decreasing trend in seedling quality with the increase of the sowing densities from 229.4grains/dm to 400. 1 grains/dm", the differences among the densities were not significant for grain yields, indicating that the sowing density for the strongest seedling was not the suitable density for the seedling nursery with two-layer plastic film for mechanical transplanting. The suitable sowing density was around 230 of grains/dm2 for the purpose of extending suitable seedling transplanting period.(2)The peak of seedling dry weight appeared at the 20th day after sowing when the leafage of the seedling was 3.8~4.1 for all the density treatments except for the least density (170.7 grains/dm2) treatment. The seedling dry weight decreased or ceased increasing, and seedling quality got worse thereafter. The higher the density, the quicker the speed of the seedling deteriorating would be. So the critical suitable transplanting time for these densities was at the 20th day after sowing or a little earlier when the leafage was 3.8~4.1.(3)The main indices of seedling quality, such as root-developing ability and dry weight of seedlings nursed in high levels of fertilizing, were significantly higher than those in low fertilizing levels ;Furthermore, tillers of the seedlings nursed in the high levels developed earlier ,and the peak tillers was greater ,but the ratio of productive tillers were lower and spikelets per panicle were less ,the difference among treatments in grain yield was not significant ,but the trend which yield was raised with the increase of fertilizer levels was obvious. According to these results, the appropriate indices for vigorous seedlings of Wu Yun jing 7 were as follows :12 cm for seedling height ,2.7 mm for thickness of fake-stem ,1.0~2.0 for the ratio of sugar to nitrogen .(4) At seedling age of 16d to 2 Id, the main indices of seedling quality, such as the root-developing ability , the sugar content of stem and sheath and the ratio of dry weight to seedling height were improved. At seedling age of 21 d to 35d, the seedling quality obviously went worse, the sugar content of stem and sheath and the ratio of dry weight to seedling height decreased. The ratio of seedlings to seeds and living seedlings of paddy field decreased with the prolonging of seedling age , seedlings per hill were reduced and empty hill percentageincreased, the number of seedlings in paddy field decreased. The number of seedlings in paddy field in the high sowing density treatment was higher than that of the low sowing density, it was reduced with the increase in fertilizer levels at seedling age of 16d and high sowing density. It was raised with the increase in fertilizer levels at seedling age of 21d and 35d. The results adequately indicate the interaction effects on quality among sowing density , seedbed fertilizing and seedling age. It has referenced value in getting convenient measures of seedling for mechanical transplanting.(5)The grain yield was significantly decreased with the prolonging of seedling age. The influence of sowing density on yield wasn’t significant. The effect of seedbed fer更多还原