不同密度对精量穴直播水稻产量的影响

Effects of different planting density on grain yield of precision hill-drop drilling rice

以2个超级稻品种培杂泰丰和玉香油占为材料,考察了不同机械精量穴直播密度对精量穴直播水稻产量的影响,结果表明：与人工撒播（对照）相比,水稻在4种精量穴直播密度（1.48万株/667 m2、2.38万株/667m2、2.22万株/667m2、1.85万株/667m2）下均表现出较高的有效穗数、群体颖花量和产量水平,不同穴直播密度对2个品种的千粒重的影响均不明显；其中培杂泰丰在4种精量穴直播密度下（P1～P4）分别增产69.07%、40.73%、34.34%和35.09%,玉香油占在4种精量穴直播密度下（Y1～Y4）分别增产109.97%、45.14%、84.86%和46.32%,差异均达到显著水平。不同精量穴直播种植密度中,20cm行距在2个品种间的表现一致,产量和收获指数均达到最高,说明适宜的行距可提高精量穴直播水稻的收获指数；培杂泰丰产量以25cm行距为次高,（35＋15）cm宽窄行和30cm行距产量水平相当；玉香油占以（35＋15）cm宽窄行和30cm行距产量为次高且两者之间差异不显著,25cm行距再次之。精量穴直播水稻地上部分个体生物产量以30cm行距和（35＋15）cm宽窄行为最高,而群体生物产量以20cm行距为最高；增加行距可提高个体生物产量,在适宜行距基础上可形成较高的群体生物产量。精量穴直播水稻在4种精量穴直播密度下均表现出较高的净光合速率,但蒸腾速率、气孔导度和胞间CO2浓度的差异因品种而异；适宜的行距可保证精量穴直播水稻具有较高的群体光合量。因此,提高精量穴直播水稻产量的主要途径仍是在保证一定群体有效穗数的基础上提高精量穴直播水稻每穗粒数,充分发挥精量穴直播成行成穴的优势,促进个体与群体、产量及其构成因素之间的协调发展以及增加群体光合量,从而提高产量。

Two varieties of super rice,Peizataifeng and Yuxiangyouzhan,were used to study the effects of different planting density on grain production of mechanical precision hill-drop drilling rice. The results showed that different planting density of precision hill-drop drilling rice produced high valid panicles,high population total number of spilelets and high yield compared with manual boardcasting（controls）;but it had no significant effect on 1 000-grain weight of both varieties.The yields of Peizataifeng with four densities（P1-P4）was increased significantly by 69.07%,40.73%,34.34% and 35.09%,respectively.The yields of Yuxiangyouzhan（Y1-Y4）was increased significantly by 109.97%, 45.14%,84.86%and 46.32%,respectively.The highest grain yield and highest harvest index were observed in both rice varieties with row spacing of 20cm,followed by row spacing of 25cm wide-narrow（35 ＋15）cm and 30cm,but the difference between wide-narrow（35＋15）cm and 30cm was not significant in the variety of Peizataifeng.For the grain yields of Yuxiangyouzhan,followed by the same levels of wide-narrow and 30cm,and then followed by row spacing of 25cm,indicating that appropriate row spacing could improve the harvest index of precision hill-drop drilling rice.The row spacing of 30cm and wide-narrow achieved the highest individuals biological yield while 20cm achieved the highest population biological yields,indicating that increasing the row spacing could improve the individuals biological yield. Improving population biological yields of precision hill-drop drilling rice should be on the basis of appropriate row spacing.The results also showed that higher net photosynthetic rate,but the significance levels of the transpiration rate,stomatal conductance（Cond）and intercellular carbon dioxide concentration in leaves（flag leaves）varied with the varieties of precision hill-drop drilling rice.The suitable row spacing could improve the population photosynthesis capacity of precision hill-drop drilling rice.Therefore, the main pathway to improve grain yield of precise hill-drop drilling rice is to guarantee grain number per panicle on the basis of certain population valid panicles,to highlight the production superiority of deepen fertilization and mechanical hill-lined characteristics,to coordinate the contradictions between individualsand-population and yield and its components,to improve population photosynthesis capacity,and therefore to culminate in a performance of high yields of precise hill-drop drilling rice.